| WELCOME to the anvilfire Guru's Den - V. 3.0 |
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THIS is a forum for questions and answers about blacksmithing and general metalworking. Ask the Guru any reasonable question and he or one of his helpers will answer your question, find someone that can, OR research the question for you. This is an archive of posts from January 17 - 24, 2006 on the Guru's Den |
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 Grant Sarver Induction Forge Heater  |
| - guru - Tuesday, 07/11/06 13:50:08 EDT |
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Dave Boyer: Thats a lot of juice for doing nothing! This induction unit has the contactor on the primary too, so power draw is like 2 amps. OBTW: I used to use my 'ol Goldstar with the foot control "on" even when stick welding at the bench. Sure nice to have that amp control. |
| - grant - Monday, 07/17/06 01:01:59 EDT |
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Grant: Did You use the HF to start the arc allso? Speaking of the HF on these machines, Mine isn't working, makes a weak spark if really close, or nothing. The points are clean and set at .008 as per the spec. My guess is the capacitors might be shot, but I havn't checked the ohms on the HV transformer yet. Any ideas? This machine had been sitting for a while before I got it,I don't think the owner before Me ever got it working. Actually Mine is an Airco, so the serial #'s in the specs may be irevelant. |
| Dave Boyer - Monday, 07/17/06 02:47:12 EDT |
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I origionaly sent this to Anvilfire FAQ but realised this is probabely a better place. I was reading through your sword crafting guide and found myself at odds with the statement of spring leaf swords being a urban legend. Our local blacksmith has made a sword out of a spring leaf. Given, It's impossible to do without a forge and a profesional sharpening service. He heated it up to an amazing heat before forming it. Apparantly after he treated it he found it was too hard to put an edge on, he wore through an entire stone in the effort. In the end he sent it off to a friend who owns a company that makes and sharpens blades. They used a laser to put an edge to it. If you would like I can probabely obtain some photos of the sword. However it is possible to form a sword from a leaf, if being difficult to the point of being impossible by any real standard. |
| Rayn - Monday, 07/17/06 06:12:32 EDT |
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A friend, knowing I've been wanting to get try blacksmithing for a while, gave me what I can only describe as a stainless brick. Which alloy, he doesn't know. It's roughly 12"x4"x3" milled all sides. Until I spend college fund money, it's as close to an anvil as I'm going to get for a few years. It's soft, a firm whack with a peening hammer leaves a good ding. I've lurked enough to know the issues: not enough mass, too soft. But, until I can afford a Peddinghaus, I'd like to use it as a door into blacksmithing for small things. My question is this: is there a SAFE way you can recommend that I can get this thing heated and quenched so it's not so soft? Can I mitigate mass issue by "casting" it into a concrete pillar that would set the "face" at right height, and leave about an inch of the "brick" sticking up? |
| jgourlay - Monday, 07/17/06 06:26:37 EDT |
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Rayn, Without knowing more than what "an amazing heat" would be and without knowing what treatment was given, it is difficult to comment. However, after hardening a sword, it must be tempered. The local smith may not have tempered it. |
| Frank Turley - Monday, 07/17/06 08:56:29 EDT |
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Ryan, I think that that part refers to a website where they advocate *cold* straightening a leaf spring and then grinding it down to a sword like object---no forging involved at all! This technique gives most smiths the willies what with the possibility of inducing cracks and the damage to the human body of whaling on a pice of tempered spring with a large hammer trying to "damage it" back straight. Spring steel alloys are often suggested for swordmaking; though in general we suggest that you buy *new* stock from a spring maker or steel supply company and not be *guessing* on if that spring is ready to snap from use damage. If it was too hard to sharpen then he did the tempering wrong and the blade may be much too brittle for safe use! Please get it checked before someone gets hurt! Thomas |
| Thomas P - Monday, 07/17/06 10:45:58 EDT |
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If its too hard to grind an edge, then its much too hard for a sword and is liable to shatter. As Frank explained it would have to be tempered. Blacksmiths work spring and blade steel with carefully graded temperatures characterized by their colors. Too high a heat will ruin the steel. A smith sometimes has need of some amazing grace but never an amazing heat! |
| adam - Monday, 07/17/06 11:00:48 EDT |
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jgourlay; unless that SS brick is an alloy that can be quench hardened all heating it up and quenching it will do is to *soften* it more. Most SS alloys are not quench hardening. Thomas |
| Thomas P - Monday, 07/17/06 11:03:13 EDT |
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jgourlay-- why ruin what sounds like a beautiful paperweight? why make smithing harder than it already basically is by tormenting yourself with jive tools and material? this is like making a sword out of a vehicle spring. It can be done, just as your stainless brick can be used to pound upon. in both cases, so what? give yourself a break. get off to the right start. get something better. |
| Miles Undercut - Monday, 07/17/06 11:09:57 EDT |
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I think jgourlay is trying to achieve what I've seen as a Japanese swordsmaking anvil, although his choice of steel (not much a choice as a lazy way out of finding the right material) is off. You dont need a Peddighaus or P.W. or brand new brand name anvil to start off with, especially if your on a budget. I'm sure there's a FAQ here at Anvilfire that could give you more than I can. All I CAN say is listen to these guys, they know what they're talking about and WILL point you in the right direction every time. |
| - Nippulini - Monday, 07/17/06 11:29:50 EDT |
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My shop has a concrete floor. What is the best way to mount my bender and air compressor so that they can't move around? |
| - Laura - Monday, 07/17/06 11:59:21 EDT |
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jgourlay 12x4x3 is approximately 40# which would be nice for jewelry but almost useless for forging any iron except wire and small nails. It would make a nice bench block. 75# is just about the very minimum. Concrete wont help - though welding it onto another piece of heavy steel would. Sure a really skillful person with a lot of time can make even a 20# sledge hammer work as an anvil. Smiths in Asia do this all the time. You will have a very hard time learning with such a tool especially on your own and it wont be fun. So skip it. The most important thing is mass and shape. Hardness is a luxury that one can do without. In fact its not really desirable in a first anvil. Go by a scrap yard and see if you can pick up a piece of RR track, heavy shafting or heavy plate. Try to get at least 100#. Better still sniff out your local smithing group and chat with them. They will know where the heavy iron is! :) |
| adam - Monday, 07/17/06 12:13:33 EDT |
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Rayn, I have been doing stock removal weapons for years, and forging weapons for a couple now as well. From what you say, it sounds like the blacksmith who made that blade does not know much about bladesmithing. If he heated the spring and forged out a rough sword, the next step that he should have done would be to aneal the piece (heat it, let it cool very slowly, making it softer). After the anealing, all the beveling and final shaping is ground in. Durring this process, I actually put a rough edge on the weapon as well, that way all I have to do after the heat treatment is clean up the blade, then do just a slight amount of grinding to hone up the edge to where I want. Then it is a common practice to nomalize, at least once, which helps to releave some of the stress from the forging and grinding process before the hardening. And everyone else who posted is right as well, after the heat hardening, the blade must be tempered to relieve excess stress and prevent it from being brittle. But it seems to me that even if a leaf spring were heat hardened down from a welding temperature (which would ruin it anyways, it would fracture and crack all to pieces) and it were very hard, you would still be able to grind it, granted it would be more difficult and time consuming and would eat at a wheel faster, but the whole wheel gone just to try and sharpen sounds a little far fetched to me. I could see that if he were trying to grind in all the beveing as well, but not just an edge, there sould not have been that much material. Oh, and like others have commented, if that blade has not been tempered, it will fracture, the moment a goodamount of stress is placed on it. In fact, with a true and well made sword, one can flex the blade a substancial distance and it will return to true, no bending nor breaking, but if you were to try that with a superhardened piece of spring with no tempering, it would break and be very dangerous, as pieces could fly off in all directions and serously harm others. So, unless that sword is just a display piece and it will see no use, I would not ever use it, for cutting tests, combat (if it has a sharp edge, dont use it either way, too dangerous), or anything else that might stress the blade. Oh, and as for it being impossible to make a sword out of a leaf spring, it is not, its just most in their right mind would not want to since there are easier things to do. I believe that the leaf spring swords talked about in the sword making myth page, were the kinds that people think that you can make by just tearing off an old piece of car suspension, then grind it into a "sword." Well, one could do that I suppose if the leaf spring were straight (like Thomas said, cold straightening a spring is not the way to go, if you even could do it cold, which is not too likley with out an infinate amount of hammering). As for the grinding its just the amount of grinding that exists in doing a stock removal weapon the size of a sword out of a non annealed piece of steel the grade of a leaf spring is basically madness, possible, but no where near worth it for all of the time and grinding equipment you will go through (wheels, belts, ect). Now, you can forge out some decent stuff beautifully with it, if you know the proper steps to make a blade and how to properly heat treat. |
| - TarAlderion - Monday, 07/17/06 12:58:14 EDT |
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jgourlay, my best advice is to check ebay. In a noble gesture my dad bought one of the anvils off of ebay that are the mexican made anvil (i believe they claim they are made in mexico out of american steel ) because he thought that it would be nice to have a nice flat faced anvil for finishing work. i think the anvil weighs around 100 pounds. now , before i start a whole other string of discussions , remember that this is just a starter anvil and upgrade as soon as possible. while these ebay anvils are not that massive, they will work for small work (or in my case for smooth finishing work ). Personally, I started out on a RR track anvil that was made of light gauge rail. The whole thing weighed maybe 30-35 pounds. I learned alot (like how many lag screws it takes to keep a light anvil attached to a stump) but it was a start (and one that I would not reccomend to anybody else.) |
| - sandycreekforge - Monday, 07/17/06 13:02:07 EDT |
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Note regarding glass torch work: "Beadmakers" usually refer to themselves as lampworkers (which identifies them as opposed to folks who make beads out of other stuff, and lampworkers make other things as well), and they refer to their heat source as a lamp, burner, or torch. It is worthwhile to note that a lampworker's torch nowadays is a SURFACE MIX burner, meaning the propane (usually) and oxygen do not meet and mix until they reach the burner head, and they actually meet and burn in open air. This makes it much easier to vary the oxidizing/reducing characteristics of the flame to an extreme degree and change the flame's length without changing tips. Stainless block (brick): This is a 40lb chunk... fairly sizable. If you want to get started on some 1/4" stock, Jgourlay, I would encourage you to do so. |
| T. Gold - Monday, 07/17/06 13:22:14 EDT |
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Laura- to fasten your bender and compressor to a concrete floor, you need to drill holes in the concrete, and then use a special concrete anchor bolt. You can rent a hammer drill designed to drill concrete at most rental yards, they dont cost too much for a day. Around here, they make you buy your own bit- about 10 bucks. Then you need some concrete bolts. I find that the sleeve anchor style is the easiest to use- I bolted my bender down with 4 "Lok-Bolts" from Powers- www.powers.com look under mechanical anchors. I used a 5/8" diameter by about 3" long, tighten em down tight with a wrench, and have since bent somewhere around 20,000 parts with it in the last ten years. A good industrial supply house or fastener company will carry a much better selection of these than a home improvement store will. There are other types that rely on pounding in, or pins that make the anchor expand, but I find they screw up a lot more often- the sleeve type are usually a lot easier to set, and hold just fine for what you need. |
| - Ries - Monday, 07/17/06 13:31:27 EDT |
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So, i got like 80 pounds of Anthracite Finings by accident, how am i supposed to light them? apparently the local historic village uses this same stuff, Heritage Park, in Calgary alberta, anywyas, i know its not going to be that great for forgning, but i would think it can still be done, help me |
| Cameron - Monday, 07/17/06 14:39:16 EDT |
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sandycreekforge my son works for the railroad and he replaces the trucks under the rail cars. i asked him what they did with the wheels and axels that had to be replaced, and he said they rebuild all the axels and wheels if it was at all possible to rebuild them. ron60. |
| - ronald rumfelt - Monday, 07/17/06 15:01:17 EDT |
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ok...when u heat metal to forge it it in to shape u let it cool slow so the grain size would get larger right (but if it doesnt i would think its from heat being "knoked out")and thus making the metal less dense and weeker so would u not have to harden it more than 2 times before quenching on the 3rd???if so how would u know the# of times u would harden it |
| thomas mayhugh - Monday, 07/17/06 16:39:04 EDT |
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Grant, How well would your induction unit work for forge welding damascus billets starting in the 4"x4" range and working down? Would you have to have multiple coils and if so, what increments would you suggest? You mention already welding with your set-up. Did you use flux and if so, did it have any effect on the coils or other components? Any idea as to how heating a 4x4 layered billet would heat differently than a 4x4 tube with steel powder in it for mosaic damascus? Thanks Patrick |
| Patrick Nowak - Monday, 07/17/06 16:54:41 EDT |
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Laura, My 5hp Ingersoll-Rand T-30 60 gallon compressor jus tsits on the floor on a rubber mat; no anchors. I use a six foot length of 1-1/2" rubber hose betwee the receiver and the air lines to absorb sudden changes and vibration. In a year, the compressor hasn't moved at all. I prefer to use drilled anchors for securing tools against movement. Depending on the type of tool and the stresses involved; I may use lead anchors and lag bolts for a bender, since the loads are mostly lateral, but for a compressor which vibrates considerably, I would probably use threaded female anchors setin expanding grout. Then I would put a vibratio damping mat between the compressor and the concrete floor and bolt it down ,using an anaerobic thread locker on the bolt threads. For really jumpy things like powerhammers, I'd go with threaded anchors epoxied into deep holes in the concrete ( at least 8" deep), and the anti-vibration mat and bolts with anaerobic thread locker. I would prefer to cut the floor and pour a proper foundation, with anchors cast in place, but that may not be a viable solution in every case. With power hammers, you can pretty much count on any fasteners coming loose if they're not sealed or safety-wired. |
| vicopper - Monday, 07/17/06 17:00:14 EDT |
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Uh Cameron; why not ask the folks near to you how they are managing to use the fines? I know that bituminous fines are used by mixing with water and letting the sludge coke into a solid mass that can then be worked like regular coked coal. Thomas, larger grain would not necessarily be less dense I would think that single crystal would be the most dense. Modern alloys generally have additives to help prevent or slow down grain growth and of course forging is a method or reducing grain size---mechanical deformation leading to dislocations leading to re-nucleation of grains... However most bladesmiths normalize their work several times before hardening, three times has been accepted as a "magic" number with diminishing returns increasing after that. After normalizing you then heat and quench---generally only 1 time though there are some alloys that do improve by multiple hardening runs---they can be a pain in other ways too so they are best not to start out on. After quenching you *IMMEDIATLY* draw temper on the blade and again most bladesmiths will do this several times as well. thomas |
| Thomas P - Monday, 07/17/06 17:44:33 EDT |
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Ineed to know what would be the lenth of the ark of a cegment of a circle that has a cord lenth of 42 in and a cord hight of 12 in and a radiaus of 24.375???? (how long of a pice do i need to cut ??to bend the ark) |
| Bill E - Monday, 07/17/06 18:24:35 EDT |
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Bill E: Sounds suspiciously like a homework question. Now if you are using it in a particular application than that is a different story. |
| Ken Scharabok - Monday, 07/17/06 18:49:39 EDT |
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Hi Bill Epps circumference of 76.5375 divide in half is 38.36875 I think. My thinking cap is not on very tight at the moment. Better have someone else figure this on |
| - mousehole - Monday, 07/17/06 18:51:23 EDT |
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Hi Ken It is Bill Epps. He is a bit old to be in school. You math guys better help him on this one. I am pretty tired and just took a WAG. :) |
| - mousehole - Monday, 07/17/06 18:52:49 EDT |
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Ries and Vicopper thank you for the help with fastening to concrete I really appreciate it! Laura |
| - Laura - Monday, 07/17/06 18:58:58 EDT |
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ok well what is normal izing and how is it done also what would u say is the best materials to use for making a sword and i dont care how hard it is to make a blade from them i just want to know wich combo would be best and y |
| thomas mayhugh - Monday, 07/17/06 19:28:06 EDT |
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which is the best book to read for learnign all there is to know about forging |
| thomas mayhugh - Monday, 07/17/06 19:29:45 EDT |
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Thomas: Right here would be a good place to start: http://www.anvilfire.com/FAQs/swords_faq_index.htm |
| Rick - Monday, 07/17/06 20:01:13 EDT |
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Bill? Why not draw it out and measure? |
| JimG - Monday, 07/17/06 20:15:05 EDT |
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OK, I need to correct an error in one of my posts. The operating efficiency of an induction coil used for HF pipe welding is indeed about 20%. However, the system efficiency of an induction unit used to HEAT a tube or a billet is the operating efficiency to the bus times the operating efficiency of the coil. Now we know that the bus efficiency is about 80% and the coil is estimated to be about 60% (more or less depending on how well matched it is to the load) and we get a system efficiency of about 50% more or less. Way too many big equations for me to work out but I think the realistic efficiency would be in the 50-70% range, not the 20% I quoted earlier. Sorry for the confusion, Grant. Don't quote me on the price of the Tocco unit, it was over 6 years ago that I saw it in their shop and I didn't write anything down. Maybe it was $5000. Tocco bought Ajax Magnethermic last year and I am sure their prices went up to offset the purchase of Ajax. I just got back from the social event of the year in Left Tennessee: The Grand Opening of a new Tractor Supply Store! YEEEHAAA! |
| quenchcrack - Monday, 07/17/06 20:58:06 EDT |
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Thomas: Durring the process of forging and grinding a blade, different sections are heated and placed under stress in doing so, different grain sizes will form over the length of the blade. This inconsistancy can cause problems with blade performance when finished, as well as some problems durring the heat treating. To normalize, the enitre length of the blade is heated consistantly to about a cherry red (to keep it simple)or so, then allowed to cool uniformally, in doing so, the grain size in the blade will become more uniform over the entire length and areas of different grain and stress will be removed. Often normalization is repeated multiple times to ensure that the grain is as uniform as possible before the heat hardening. As for good blade making steel, it has to have two qualities to be considered a blade worthy material. First, it must be hard so that it will hold an edge, and it must be flexable and resialiant so as not to either bend or break when put under the stress it will face in battle. High carbon steels are the only thing to use, mild and medium grade are far too soft, wont hold an edge and will bend very easily. I would not recomend any stainless either, 440 is about the only grade that you can do a blade out of, but that is best left for knives that arent of the size nor under the same stress as a sword. The other grades of stainless are very soft and almost "gummy" if you will. So, personally I would not go with anything besides a high carbon steel. Spring steel (5160) is very good for swords, its hard enough to hold an edge and it is extremly flexable and resialiant so it wont fracture. Some of the more common blade making steels are the 5160, Q-1, W-1 & W-2, 1095, and 52100 just to name a few. Basically any steel with a carbon content greater than .5% carbon is good (high carbon, spring, and tool steels). Now, if you were to do pattern welded, laminated, or damascus blades, you would forge weld a high carbon with a lower carbon, but that is a different story. I would say that spring steel is the best choice for a sword due to its huge amount of flexability, it hardens up nicly, and holds a good edge. |
| - TarAlderion - Monday, 07/17/06 22:23:48 EDT |
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Sorry noticed a mistake. Its not "Q-1" its O-1. And I also forgot to throw in that the entire 10-series will make good blades. 1060 (basically spring) and 1050 are a little tougher for sword use than the upper 1084 and 1095. |
| - TarAlderion - Monday, 07/17/06 22:41:55 EDT |
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Heat Treatment: The absolute best way to find out how to heat treat and weather to normalize after forging is to get the handbook from the steel manufacturer and follow the directions. This of course doesn't work on "junkyard" steel. Some steels shouldn't be normalised after forging. None of the tool steels I ever used were supposed to be heated and quenched more than once, and tempering on MOST steels is supposed to be done for 1 hour at temperature plus 5 minutes per inch of thickness, 1 time only. There are a few tool steels that are to be drawn twice, not necesairily to the same temperature. When "running the colors" to get a diferential temper on a blade You CAN NOT temper for 1 hour, so some of the blademakers are tempering multiple times to try and make up for the difference. |
| Dave Boyer - Monday, 07/17/06 22:44:25 EDT |
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Bill E: I got 50.617" by calculation. I didn't lay it out, If I goofed it could be WAY OFF. |
| Dave Boyer - Monday, 07/17/06 23:01:16 EDT |
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That looks suspicously like Bill Epps. I recognize the handwriting from his iForge demos :) We do Bills homework here and most anything else he asks! Bill theres a slight error in your numbers : the height, half the length of the chord must form a rt triangle with the radius as the long side - this would require a radius of 24.187" so I am going to assume thats the case. Then the angle subtended by the chord is 120.51 deg , very slightly over 1/3 the circle so the length of the arc will be 1/3 the circumference ie 1/3 of 2Pi x 24.187 = 50.66" check my work! |
| adam - Monday, 07/17/06 23:10:50 EDT |
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PS if I use your number for the radius I get an arc length of 51.27. Like Dave says, I would lay it out to be sure. I can do math but I never mastered arithmetic :) |
| adam - Monday, 07/17/06 23:18:19 EDT |
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Adam and Dave I am glad your math caps are on. I was asleep at the wheel on that one. :) |
| - mousehole - Monday, 07/17/06 23:25:40 EDT |
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Adam: Where Did You get 24.187 from? I used the same method as You, but used 24.375" for the radius [hypotenuse] 21" for altitude and 12.375" for the base to get an angle of 118.9795 deg. total. or .3305% of the circumfrence. |
| Dave Boyer - Tuesday, 07/18/06 00:44:30 EDT |
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Still having modem and PC problems. . . be back later. . updating software. GRRRRRRRR |
| - guru - Tuesday, 07/18/06 00:59:48 EDT |
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Dave I understod the chord length was 42" and the distance from the center of the chord to the center of the circle was 12" so root(12^2+ 21^2) would be 24.187" the radius of the circle - this gives an angle of 120.26 deg. But if you assume the radius is correct and calculate the height the answer might be what you calculated - too sleepy to check. I do think those three numbers that Bill gave are slightly inconsistent |
| adam - Tuesday, 07/18/06 01:13:16 EDT |
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Patrick: I wish there was a better answer, but induction falls flat when it comes to pattern welding. First, 4 X 4 requires a fairly low frequency (500-1000Hz), second, equipment for heating a 4 X 4 is usually a comercial billet heater. And lastly laminates really screw up the magnetic field, that's why they use a laminated core in a transformer. The tube filled with powder would be even worse. sorry Quenchcrack: Thanks for the update. The discussion has been fun and it really helps me understand where I'm not giving all the needed information and where any confusion might creep in. |
| - grant - Tuesday, 07/18/06 01:13:20 EDT |
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Well, I used 24.375 radius, 42 chord length, 12 height and get an answer of 50.6167 from my CAD. Actually you only need the radius and one of the others. |
| - grant - Tuesday, 07/18/06 01:19:15 EDT |
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Hmm, guess you don't need the radius if you have the other two. So, any two will give you the answer. |
| - grant - Tuesday, 07/18/06 02:07:41 EDT |
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To Bill E: My apologies. Didn't associate name with you. |
| Ken Scharabok - Tuesday, 07/18/06 02:26:33 EDT |
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Adam: The rise of a chord is from the chord to the diameter. Asuming that is what Bill is using for hight, when I saw Your answer I checked the sides 12.375", 21", 24.375", and it does make a Rt. triangle, so I figured that the 24.375 radius was OK. Grant, You COULD solve for the radius knowing the length and rise of the chord, I used to do that to figure the bullet nose radius for pilot pins, but it is another bunch of steps. I guess not an issue with CAD, fortunatly We had calculators when I was doing it, be a real bear with a trig table, pad,& pencil. |
| Dave Boyer - Tuesday, 07/18/06 04:03:18 EDT |
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Yet another induction question: This is only to satisfy my technical curiosity. Would the induction affect the heat treatment of a higher carbon steel? I was just wondering of those emag eddies would somehow scramble the normal formation of grain. |
| - Marc - Tuesday, 07/18/06 08:36:56 EDT |
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Marc, The first time I saw induction heating at work was at the GE Forge and tool works, a horseshoeing tool supply. They used it to harden the hoof nipper blades. Just a portion of the blades was heated, the business end and a little behind. This was done on both blades at once after the riveted assembly. I don't think there were any adverse effects, as GE is considered top of the line. Chords and Arcs. I am not too savvy when it comes to geometry or cad calculations, but did we miss something by not asking the cross sectional dimensions of the stock to be bent? Are we working with the mean diameter of the stock, the OD, or the ID? |
| Frank Turley - Tuesday, 07/18/06 09:23:48 EDT |
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Bill Epps, Final Answer: First I checked Bill's numbers. When you have more than the minimum to define what you need they can be inconsitant. Bill's numbers of Cord = 42, Rise = 12 and Radius = 24.375 are correct, according to my old copy of Mass2 (based on MACHINERY'S HANDBOOK). There are several ways to calculate the answer. The constructivist method I use is to determine the angle of the Isosceles triangle created by the cord and radius with the center of the circle one corner. Using a right triangle for half of the Isosceles you use half the cord and the radius minus the rise. Dimensions = 21, 24.375 and 12.375 In this case it is 118.98 degrees. That is .3305 of the full circle. So the length of the segment is .3305 times the circumference of the full circle. So, 48.75 times PI = 153.153. Times .3305 = 50.6167... Correct Answer: 50.617" segment. Dave and Grant had the right answers. However, the whole thing is so close to being 1/3 of a circle and the angle being 120 degrees I would check the layout and see it that was what was intended by the designer. IF that is the that case the segment is 51.051. |
| - guru - Tuesday, 07/18/06 09:46:23 EDT |
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Frank, I assumed Bill was talking about center lines as he has done enough of this to know. But it is a good obsevation and he did not state it as part of his question. I'm still checking in via dial-up on a backup PC (which I spent all weekend rebuilding. . GRRRRR). Had to do a clean install of Windirt and lost tons of files and old programs. |
| - guru - Tuesday, 07/18/06 09:53:31 EDT |
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Fancy Math: I defined a lot of questions in my old Mass2 calculator similar to the way it is on the on-line Mass3j by allowing any of the possible knowns to be entered including area and sometimes volume (see Polygons). This means setting up a lot of cases in the programming but that is irrevelent as the user does not care what goes on behind the scenes. What the user wants is simplicity and the flexibility to enter what they know. Sometimes what you know is that you want X volume in Y length in "this shape". OR they want to do some "what ifs" based on an odd variable. Too few computer based calculators work this way. |
| - guru - Tuesday, 07/18/06 10:12:57 EDT |
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We all agree that half the chord, the rise and the radius form a rt triangle with the radius on the hyp. What do you guys get for root( 12^2 + 21^2)? I get 24.186777 - not 24.375 |
| adam - Tuesday, 07/18/06 10:40:44 EDT |
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Adam, You need to make a clear diagram. That is the hypotenuse of the right triangle between the cord and the arc or the cord of half the arc. That sits on top of a right triangle under the cord. 12, 21, 12.18677 top triangle (cord of 1/2 the arc) 12.375, 21, 24.375 bottom triangle (half the Isosceles). Calculating the top triangle serves no purpose. I did the same then tossed it. The bottom triangle is used to find the angle or sweep of the arc which can be used via proportioning the curcumference to find the length of the segment under the cord. |
| - guru - Tuesday, 07/18/06 10:57:52 EDT |
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We are using the same method - the key is to find the angle swept out by the arc - theta then s = theta/ (2pi)r Now using just the Radius, r, and the Chord, c the arc length s and the angles in radians: s = 2* asin(c/2r) * r = 50.61674614 but also s = 2*atan(c/2h)*r = 51.26794786 and s = 2*acos(h/r) *r = 51.48279432 We are ALL right and Bill is wrong! Sorry Bill! He gave 3 numbers where, as Grant pointed out, only two were needed. Those three numbers are inconsistent, so depending on which two you pick for the calculation you can get three different answers |
| adam - Tuesday, 07/18/06 11:14:15 EDT |
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ummm errata ... s = theta * r where theta is in radians |
| adam - Tuesday, 07/18/06 11:15:10 EDT |
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ronald , thanks for the heads up on the train axles , I had a feeling that that was what happened (couldn't see any corporation scrapping out that much steel unless absolutely neccessary.) I mentioned it earlier, and now I've finally got around to doing the math. This is in the vein of me building something similar to the KA75 (or at least based on the same general idea). So i did the math, and as close as I can figure the anvils on those hammers weigh only about 200-225 lbs. If the hammers really produce 500psi of striking force ,this seems like an awfully light anvil for that much for that much force. Is there some math or mechanical principal that I am missing somewhere? Thanks everyone, -Aaron @ The SCF |
| - sandycreekforge - Tuesday, 07/18/06 11:37:11 EDT |
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Math Errors: Adam, Nope, you are still confused and need to start over and draw a clear diagram. Your logic is incorrect. Bill's cord, height and radius check out. There is only one right answer and Grant, Dave and I got it right. The proof is VERY simple geometry. Half the cord (42") is one side of a right triangle = 21". The radius given MINUS the height is the other side = 12.375". The result, the hypotenuse is the radius given 24.375 (48.75 dia. circle). THEREFORE: All three givens are true and there is only ONE true answer and no inconsistancies. From these the length of segment is 50.617". Start at the begining. The half segment cord distance you keep calculating is a red Herring having nothing to do with the solution. The fact that this thing is so close to a 30-60-90 triangle also lends itself to many false assumptions. |
| - guru - Tuesday, 07/18/06 12:02:37 EDT |
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Note: what's "industry standard" is not always the best way to go---just the cheapest. Particularly in knifemaking when we are discussing blades much thinner than the standard 1" cross section that most of the tables in the books are based on. Cycling tempering helps as the change helps "jar" a bit more down to tougher state---at least that was the explination a research metallurgist at Batelle Institute told us when I worked for the swordmaker. BTW 1020, 1030, 1040 are 10 series that don't make decent blades and pattern welded billets do not have to be high carbon/low carbon mixes; many makers use high carbon/high carbon but with differing alloying elements. Thomas |
| Thomas P - Tuesday, 07/18/06 12:13:52 EDT |
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Hammer/Anvil Ratios: SCF, There are many long discussions on this subject that have been repeated over and over here. See our archive of April 1-7, 2006 with the efficiency chart notation. Simply put: 1) You must forget theoretical energy calculations most are full of errors and do not reflect the real world. 2) The ratio used is the weight of the anvil vs. the weight of the moving ram and attached parts (drive rod, die). 3) The greater the ratio the more efficient the hammer up to a certain point. Cost effectivness changes over time. As steel or cast iron for mass increasses in cost the cost effectivness of large anvils has come down. 20:1 gives you a 70% efficient system and is considered to be the best ratio for a heavy duty hammer. 15:1 (59%) was long considered a "normal" ratio for power hammers. 10:1 (39%) is commonly used today due the cost of steel. The loss in efficiency goes into anvil movement which is resisted by the floor or stretching the machine frame. This results in vibration. A heavy foundation can reduce the vibration and improve the effeciency. When building a JYH you use what you can find. However, I have known folks to build hammers with hollow pipe anvils. They work but are very noisy and will bounce themselves off the floor. There is a significant amount of loss and more noise than work. The KA does have a very low anvil to ram ratio. I think they offer an optional heavy base plate that improves the ratio considerably. This was a design choice so that more money could be put into the dovetail dieholder design. |
| - guru - Tuesday, 07/18/06 12:27:13 EDT |
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okay I see now - this is a semantics problem. We all have the same diagram but with different names. In my diagram the HEIGHT is the shortest distance from the center of the circle to the chord. And it turns out that thats the same diagram my mathbook uses. If you take the HEIGHT to be the longest distance from the chord to the radius then you do get three numbers that make a rt triangle and those values in the formulae above give your answer |
| adam - Tuesday, 07/18/06 12:43:45 EDT |
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...If you take the HEIGHT to be the longest distance from the chord to the CIRCUMFERENCE sorry again :) |
| adam - Tuesday, 07/18/06 12:44:35 EDT |
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Copper safety Can I use electrical wire for forging and soldering and penny welding or do I need to worry about beryllium. Can I assume that if the wire is soft it doesnt have any beryllium? |
| adam - Tuesday, 07/18/06 12:49:22 EDT |
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ok hi carbon"/"spring steel are basicaly the best but what about that one um...tungsten i read thayt stuff is like better than titanium "gram to gram" and my dad had also said that spring steel is the best to use...(he was/is one fine welder/engineer) |
| thomas mayhugh - Tuesday, 07/18/06 13:05:27 EDT |
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Adam, Copper wire is something like 99.999% pure copper. Yes you can use it for forge brazing or penny welding. Berylium is used in making bronze spring wire and hard braonzes used to make tools. The hard berylium bronze wrenches and hammers are called "spark free" and are required for working near flamable vapors and explosive atmospheres. If you find a wrench, hammer or pry bar made of a pinkish bronze then it is probably berylium bronze. The hazzard of berylium is the metal itself when machined, ground of polished. Anything that makes dust. The dust causes a reaction in the lungs that is so similar to pnemonia that it is almost always misdiagnosed. With sufficient exposure the wrong treatment you die. |
| - guru - Tuesday, 07/18/06 13:08:11 EDT |
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Steels: Thomas M, There are thousands of alloy steels. Each has advantages and disadvantages. Some are better for one application than another. Tungsten steels are very heat resistant and have great advantages at high heats. Most have other alloying ingrediants. The disadvantage is that if you are making a knife it is difficult to temper soft enough thus being brittle in thin sections and is difficult to sharpen due to the alloy content. Cobalt also increases steels heat resistance and increases hardness. Cobalt HSS (High Speed Steels) are the best for drill bita and milling cutters. But the heat treating is difficult and expensive, not something to attempt in a blacksmith shop. Alloy steels typically include nickle, chrome, manganese, tungsten, cobalt, vanadium and others. Some have a small amount and others have so much alloy that there is little or less iron than other constituants. They range from low carbon to high carbon as well as high and low amounts of the alloys. What makes a good steel for punches and hammers is not the same as a good steel for cutting edges and those for cutting steel are different than those for cutting wood or flesh. Check out Machinery's Handbook for starters. Then any of the books on bladesmithing. If you are serious the ASM metal/alloy references are good. See also our review of Metals for Engineering Craftsmen. |
| - guru - Tuesday, 07/18/06 13:26:20 EDT |
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o hey i thought i mite just give some info on me im 15 ill be 16 in sept ive been intrested in this stuff as long as i can remember i live in culpeper va.(a bum rag town) dont believe anything u read about this place sofar ive made a few designes (cant spell) and iv only grinded things sofar but the material i got to make the stuff was from bud k but rite now i cant really aford much to start a forge but i was thinking about this "wok" version of a grill from lows and use coal or this gas grill but im not sure which would be hotter or less on the wallet anyway thats o lil' bout me and thak u guys for your help so far i really apresiate it!!! |
| thomas mayhugh - Tuesday, 07/18/06 13:26:43 EDT |
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thanks for the simple breakdown on the numbers , guru , i think i can work with what i have . My concern was that there was a mechanical reason that the anvil was relatively light, but since it seems to be an economic reason, I'll just throw as much mass as i can under it. I have a (practically) unlimited supply for scrap semi axles. I have four now, and i think that with three or four more i should be able to get enough mass (and if not i also have a virtually unlimited supply of lead tire weights to make up the difference). i also have a piece of one inch plate with a 30" diameter for the base. looks like the only expensive part is going to be the control valve and cylinders ;) |
| - sandycreekforge - Tuesday, 07/18/06 13:29:08 EDT |
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thomas m. the book that the the guru mentioned , Metals for Engineering Craftsmen is available as a PDF format ebook at http://195.92.230.85/Publications/articles/Publication_tcm2-7494.asp this is put out on various sites by the British government, so I'm pretty sure downloading it doesn't break any laws. This agency also has several other Ebooks about blacksmithing at http://195.92.230.85/Index.asp just type blacksmith in the search box and it should bring up 4 different Ebooks in PDF format. Enjoy. |
| - sandycreekforge - Tuesday, 07/18/06 13:41:32 EDT |
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Copper, thanks! I had heard that busbars have berylium so I wondered how pervasive that stuff was. But ordinairy elec wire needs to be very soft. I assume that if the copper is soft or can be annealed to soft it wont have Be. |
| adam - Tuesday, 07/18/06 14:15:42 EDT |
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Thomas P: you are exactly right about the lower 10-series, not enough carbon to be decent for blades. I got caught up in other things and accidently forgot to exclude those (thats what you get for beign too general). I did mention at least .5% carbon though, which I suppose technically would exclude them (glances away). My mistake. Oh, and I didnt mean to come across as pattern welding having to be high carbon to low carbon mixes, but, that usually tends to increase the contrast in the coloration. I myself have done some high to high carbon stuff. Its difficult to write what I mean sometimes, I suppose, especially when I dont want it to be ten pages. I usually mess these things up when I am trying to condense or simplify. Thomas M.: As for setting up a forge, it depends on what you intended uses are. I don't know if I would recomend messing around with grills. Usually they arent shaped quite right for what is needed, and there are pleanty of better things you can do for less money. If you want to use coal, and you want something cheap, you can go with the breakdrum design, and use an old hair dryer with the heating element disconnected for a blower. For a gas forge, you will need a bit more. The gas grills will not get anywhere near hot enough to do any forging with the way they are, their insulation factor is far to low to hold the type of heat needed in forging, plus that burner system doesnt have the punch to generate the heat you need. It sounds like your main goal for the forge is weapons production. I personally use a propane forge. There are pros and cons to each type of forge and it really depends on what you are after in your work. The reason I went with a gas forge was that, first of all, in my situation, propane is easier to come by, and cheaper than buying coal. Gas forges are also a bit easier to use, you just turn on the gas and light it up (then adjust gas flow and oxygen intake to get it running where you desire, a neutral flame, oxidizing flame, reducing flame, ect.) With the coal forges, you have to know what you are doing when setting up the fire, and how to build it right for what you need (which I am not the person to ask about coal forges). Propane forges are also a bit more economical in fuel usage, and you can get them hotter, easier. The type of forge a person uses is really comes down to personal perefrence. Coal is no better than gas, and gas is no better than coal, just depends on what you want to use. For more info on forges, check out the FAQ, cant beat it. There are lots of things about forge construction, operating stats, and whatever else you need to know. Oh, and a note on titanium, and tungsten in blade uses. Jock has it down perfectly in his post BTW. As for what I want to say, firstly, titanium has been taken and exagerated by hollywood and turned into a high tech sword material that far surpasses anything else, kind of like what they have done reguarding the katana and japanese bladesmithing. Katanas and folded steel do not posess the ability to cut cleanly through other swords, cement pillars, cars, and what ever else. They are like any other sword or knife, they were not better than the weapons produced in europe durring the medieval period either. Infact, all of the hollywood combat they do with swords is improbable, you never parry/block/deflect blows with the edge of a weapon, it will ruin the weapon, causing chiping and big gouges to form in the blade. Physically what is done with blades in the movies would destroy them. Sorry about that little rant, I just cant stand that type of thing. Back to titanium, it is not what you would want to use for a sword blade. It sounds cool, is light weight and extremly strong, but it would snap on you in an instant. Its far to difficult to work with with out special equipment and skill. The other thing is, you dont want a sword to be that light, it needs to have weight and mass. The mass creates momentum in a swing which increases the force of impact the blade has upon contact. And, I dont think you could afford to use titanium in a blade, that stuff is very expensive. Stick with the steel. |
| - TarAlderion - Tuesday, 07/18/06 14:35:57 EDT |
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On the KA-75. I remember a brief conversation with Bob Bergman at one time on it. He remarked it wasn't intended to be a forging hammer, but rather either a substitute for a striker or for one shot die/jig work. I have a friend who has an ornamental ironwork shop in the general area. He has a 25 LB LG for light/delicate work and a large, self-contained air hammer for heavy stuff. To compliment it he has a KA-75 run off of a fairly standard portable shop compressor. Say he is putting the flame waves at the top of a finial. He has top and bottom dies ready to go in the KA75. After forging one stroke of the KA-75 puts in the waves. However, name escapes me, but there was someone at a recent Quad-State who was using a KA-75 to forge hammer heads. As I recall he was having difficult due to the compressor recycle/refill capacity he was using. Perhaps Nathan Robertson, Jackpine Forge (jpine@paulbunyan.net). For those not familiar with him he makes custom-made blacksmithing tools, such as an assortment of hammer heads. |
| Ken Scharabok - Tuesday, 07/18/06 16:43:47 EDT |
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On the KA75. I am mostly using the hammer for the punching , cutting , "striker" purpose. The few times that I will use it for drawing will be helped by the fact that i have a large shop compressor , and I also have the tank off of an old compressor to use as a "dump" tank that will get installed right next to the hammer (much the way they recommend on the KA75 website. But for the most part i am going to use the hammer as a striker. Thanks for the heads up on these issues. And if I ever do decide that I need it for drawing purposes i can always "reverse engineer it" and fix it up with more of a kinyon style air system. Aaron @ The SCF |
| - sandycreekforge - Tuesday, 07/18/06 17:57:39 EDT |
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Induction for pattern welds: I would have thought the biggest problem for pattern welding in an induction heater would have been getting an even heat. You couldn't do it at low frequency though. While the billet may be large, the layers are thin & so require a high frequency. That's why laminated cores are only suitable for low-ish frequency transformers - once freq. gets too high, they get hot. Given that the flux density will not be evenly distributed & so cause uneven heating, I'm not certain if conduction would carry the heat through to the centre in a reasonable time. |
| andrew - Tuesday, 07/18/06 19:31:46 EDT |
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Which side of this hammer has the rounding face? Why is one side octagon, and one side square? (overlength link removed) |
| - Tyler Murch - Tuesday, 07/18/06 20:57:07 EDT |
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Tyler, I think this is this is Tom's design. The square face is traditionally used on the continent of Europe, and apparently, Tom likes that. The rounding face on the octagonal end is often used by horseshoers to "break the toe" (make the toe bend) and to concave the inner foot surface of a horseshoe to help prevent sole pressure. The typical American rounding hammer has two circular faces of the same diameter, one of them domed, one of them with an extremely slight "rocker". Rounding hammers are designed for farriers, but many blacksmiths use them and have them as part of their "hammer arsenal". |
| Frank Turley - Tuesday, 07/18/06 21:13:34 EDT |
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Conduction between laminates is problematic. Guess it's no worse than with a gas forge, it's also heating from the outside. given the relativly long soak time in either case it might work O.K. Guess I need to do some R&R (or is that R&D?). It's not something that comes up in industrial aplications. Patrick: How thick are your layers when you start? 4 inch square is pretty big, 2 inch would make pretty big blade. How long are you talking? The reference depth @ 100KHz (the max frequency of this machine)is around .060. That means when the material is less than about 1/8 thick the lines of the magnetic flux start crossing and cancelling each other out. Due to the magnetic qualities of steel it will heat to a little above Curie (the non-magnetic temp) and go no further. Now that is with magnetic flux on both sides of the part, not sure what would happen with a laminate. I think the same thing. |
| - grant - Tuesday, 07/18/06 21:14:54 EDT |
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Thanks Frank. I was at a guys shop last weekend who had all Tom Clarke and Hofi hammers. Decided to make my own. I could use that rounding face for tomahawks. |
| - Tyler Murch - Tuesday, 07/18/06 21:50:20 EDT |
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Tyler: I have several of those hammers. In fact I believe Tom started making them after I special ordered a couple. The sq face is a european style hammer face with a watch glass curve as is typical on a forging hammer face. The octagonal is a rounding face - about a 2.5" dia radius. Its a very nice combo IMO, when I need a straight pein I use the far edge of the anvil. I have it in 2.5# 3# & 4#. The hammers are *beautifully* forged and finished. I would love to have a 5# version too. |
| adam - Tuesday, 07/18/06 22:45:30 EDT |
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Grant, I am not actually doing any laminated billets myself, so the question was hypothetical. However, I do have a friend who is in the buisness of providing mosaic damascus to blademakers. His typical starting stock is 1.5 wide x .125 thick. The assembled billet is 4" thick. He ends up working this down to a large variety of sizes and lengths and then performs various manipulations and re-welds to achieve the final pattern. Right now, he is using a large NC Tool forge, but I was hoping the induction unit you have might be a viable alternative since his forging is limited to long skinny bars that are generally straight. Patrick |
| patrick nowak - Tuesday, 07/18/06 23:10:37 EDT |
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I did mess up (the angle was 60deg ) 5 divisnions I was to busy trying to figger out the ark that I forgott what the angle was thanks |
| Bill E - Tuesday, 07/18/06 23:43:00 EDT |
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PS octagonal rounding face - doesnt need to be octagonal its just pretty. If I were making one I would likely leave it square - point is with the rounding face you arent going to use the edges like you do on the regular forging face. I used this hammer when I took Franks class and every now and then he would dis it pointing out that a round forging face can be used at any angle wrt to the anvil face. A square face is best used standing at the heel of the anvil so that the vert edges line up with the edge of the anvil. When you do this you get awesome scissoring action for drawing out. |
| adam - Wednesday, 07/19/06 00:04:29 EDT |
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Adam: I would be really surprised if busbars had berylium, as it lowers electrical conductivity. Resistance welding contacts have some berylium, but as much as a harder point would be desired, the content is kept low enough to keep resistance from being a problem. Except for silver any alloy I know of increases resistance in copper, so electrical conductors are generally close to pure copper. |
| Dave Boyer - Wednesday, 07/19/06 01:28:38 EDT |
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induction: Grant, the books I have here recommend using two frequencies, a high frequency up to the curry point, and then a low frequency (by an order of magnitude) to bring up to welding temperature. They suggest this is only economical for large industrial machines, but given the capabilities of large IGBT's and power MOSFET's etc these days, I don't see why this would be the case. Perhaps they refer to need for some kind of feedback to identify the currie point - which would be the smith in this case. |
| andrew - Wednesday, 07/19/06 03:16:21 EDT |
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Bussbars, Maybe some exotics special purpose bussbars are alloy, Only special treatment I know, Many are tin plated to afford corrosion resistance. But bussbars are all copper, Non anealed so they retain better strength are left workhardened from the last passes through the rollers at the mill. Unlike wire thats annealed prior to being insulated, But its still hard to a degree, Not deadsoft. (Conductors within firealarm cable typically remain much harder than typical TH insulated conductors, a notable and irritating exception. I dont know if there is a legitimate technical reason for it, Or its just cheaper manufacture and the Alarm Business in general is too dumb to realise its an inferior product) Wire needs to have flexabilty to ease installation and reduce damages from pinches etc. BTW, Whats this about avoiding copper in the forge? I heard alot of warnings thats an old prank to pull on a Smith is to toss a bit of copper (penny) into the fire, Somehow it buggers up the ability to forgeweld? The only cure is to stop work and clean out all the firepot and fuel then start over? Seem odd to me, As copper is so reactive to oxygen at high temperature, I would think if it does something bad the effects would only last a short time until the copper all melted out then whatever is left behind oxidised. So, Whats the true story?? |
| - Sven - Wednesday, 07/19/06 04:48:25 EDT |
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Shopping at Fazzios Steel in New Jersey, the place has a regular area for metal stock and next to it 3 warehouses chock full of odds and ends, nuts and bolts, old tools, safes, ball bearings, anything, you name it. So, I'm there getting my usual stuff (junkyard art, sculptures, etc.) and I notice a very odd piece that nobody could identify. It's a rectangular block of iron set in a rectangular wood stand about 2 feet tall by 3 feet long. The iron block is about 8 inches by 2-1/2 feet, at one end of the face is a round groove, runs about 6 inches or so with another round groove going across the other groove. The wood stand has heavy iron strapping around it. It has a pretty cheap price tag ($59) but nobondy knows what it is. I suggested its use for blacksmithing and they agreed. What is it? I feel like I should have bought it or at least taken a shot of it. |
| - Nippulini - Wednesday, 07/19/06 08:31:38 EDT |
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oops..... when I said (junkyard art, sculptures) I meant I was shopping for stuff to MAKE (junkyard art, sculptures) with. |
| - Nippulini - Wednesday, 07/19/06 08:33:00 EDT |
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Dave & Sven. Thanks. I overheard some conversation somewhere - mebbe the hammerin - where I picked up this morsel of wisdom about berylium in busbars. I have put copper in my forges, both gas and coal, for penny welding etc and never noticed any effect on subsequent forge welding |
| adam - Wednesday, 07/19/06 08:46:28 EDT |
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Lead Tire Weights: SCF, I've posted rants on this before so I will not repeat it. Don't use them. The ONLY purpose for lead is if for some very critical engineering reason you need the high density for space reasons OR you need the softness (lead hammers, lead anvils). Otherwise most uses of lead ESPECIALLY in power hammer and treadle hammer rams) is dumb and enviromentaly problematic use where steel is a much better application. Bundled JYH anvils: If the bar you have is fairly even diametered or straight it can be bundled to make an anvil. The pieces all need to be welded to each other periodicaly and the top ends aligned very flat so that a heavy cap can be set atop and welded on. I recommend several straps wraped around the whole like big collars and welded on. I posted a drawing of doing this with flat stock here somewhere and will have to look for it. . Odd Piece: TGN, It definitely sounds blacksmithy but could be any kind of shop special. There was a time when they cast lead and zinc elements around pickets. . . What makes me wonder about this piece is that it is so large. A smith dressing a cross joint would use a relatively small tool. This thing SOUNDS huge. As a repousse' form it would be on the scale of something like the Statue of Liberty. It also sounds like the kind of thing that there should be a pair. . . The world is full of this kind of odd stuff. |
| - guru - Wednesday, 07/19/06 08:58:48 EDT |
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Math Question: Bill, I gave the answer in one of my posts where I guessed it was an even angle based on the layout. When the angle of the segment is known: 1) Calculate the full circumference (diameter * PI). 2) Divide the known angle in degrees by 360. 3a.) Multiply the circumference by the fraction above (#2). 3b.) OR if the angle is an even division of the circle skip #2 and just divide the circumference by the number of divisions (in this case 3 for 120°). When the angle is unknown then you have to calculate it. Often when you layout things like this you must fudge either the angle or the distance. Your dimensions sounded like good even construction dimensions but they scewed the angle just a bit. If that is the case then go with the answer we gave for those because it will give a better fit. But we all know that if we are making more than one we make the first sample the best we can then correct it. The following pieces will all be cut to the corrected dimension and be as perfect as we can make them. |
| - guru - Wednesday, 07/19/06 09:14:28 EDT |
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Induction Billet Welding: Grant, There may be less problem than you think. The pieces are usualy tack welded at the ends to hold the bundle together. This should help the magnetic and electric conductivity. Except for a very few rare makers that are using shim stock and razor blade steel most starting billets are only 5 or 6 quater or 3/16 inch bars about 2" wide. Once the first weld is made the rest are most often made two slabs at a time. You said that you could forge weld a couple pieces held together or a bundle like basket twists. This should be no different. But I am sure you ae out testing it now. . . The other billet that is now common is the mosiac Damascus billet. These start as a bundle of 1/4" or 3/16" square (sometimes round) bars. They are usualy two alloys and stacked in a grid to make a pattern. Billets are fairly short then drawn out to reduce the size of the resulting pattern or image. Later these are built into other billets or slices sawed off and assembled mosaic style. . . |
| - guru - Wednesday, 07/19/06 09:35:15 EDT |
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Weird Block of metal: I've seen anvils with channels milled in them used industrially for things like chain welding where they wanted to preserve the roundness of the stock. What signs of wear does it have? Looks forged on or could it be a large die from a press now being used as a JYA? Thomas |
| Thomas P - Wednesday, 07/19/06 10:30:06 EDT |
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"Dis that hammer face." Adam & All, I have a method of fullering, top and bottom, over the far, radiused edge of the anvil with the hammer, so that I don't always have to reach for top and bottom fullers. It is similar to a normal hammer blow, except that you "pull" the hammer head toward you at the last of the swing. I can fuller more easily with the round (circular) face, because I can catch it from various angles. That particular process is more difficult with the square faced hammer. As for "scissoring", it can be done with a round or square faced hammer. When you're blacksmithing, you're not always standing by the heel and drawing. You are doing beaucoup processes which have nothing to do with drawing iron on the anvil face: bending a scroll, bending a corkssrew, hammer upsetting, working in the vise, etc. We can talk about the American ethos and a bit of history. We know that the Dutch and Germans were quite early settlers in what is now the eastern U.S., but the English language and English ways predominated over time. In my huge, 1894 catalog of tools*, the circular faced hammers are favored over square. On the "Machinists' Hammers" page, all have circular faces, including the ball peen. On the "Solid Cast Steel" page, we have engineers', blacksmiths', and planishing hammers. All have circular faces save one planishing hammer. "The Sledges" page depicts all circular faces. The boilermakers' hammers have circular faces. Horseshoers' hammers are shown with circular faces. Square or rectagular faces are found on stone, spauling, and brick hammers. The American blacksmiths' hammer evolved, and it is not too unlike the Continental square faces hammer. It is formed of square stock, the difference being that the working face has the corners chamfered enough so that the face can be made circular. When I came to blacksmithing from horseshoeing in the 1960s, I brought the round faced hammers with me. In my shop now, I have a large assortment of hammers and sledges, some of them having square faces. The French hammer has a slightly rectangular face with NO corner chamfers. Most Continental hammers have a little bit of corner chamfer. I've never seen a Japanese forging hammer that didn't have a circular face. A lot of hammer styling is regional happenstance. With the resuscitation of American smithcraft beginning around 1970, catalogs began to appear which depicted all manner of hand hammers. I think this is good; we can now pick and choose. *Manning, Maxwell, and Moore, New York, Chicago, 1894. |
| Frank Turley - Wednesday, 07/19/06 10:40:42 EDT |
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Thanks guru, I'll keep that in mind. SCF |
| - sandycreekforge - Wednesday, 07/19/06 11:26:18 EDT |
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Tyler- dont post those long URL's (web addresses) it screws up the width of the window, making the text go way off my screen over towards the driveway, which makes it hard to read. |
| - Ries - Wednesday, 07/19/06 12:37:10 EDT |
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Out of curiosity I followed the link that was posted a few days ago to Tocco and called to find out what their small 5/10 kw TOCCOtron AC induction unit suitable for typical blacksmith work would cost; about $15,000 with all the items needed except the individual coils. Looks like Grant has come in at the right price point. |
| - Bob Johnson - Wednesday, 07/19/06 12:55:20 EDT |
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Out of curiosity I followed the link that was posted a few days ago to Tocco and called to find out what their small 5/10 kw TOCCOtron AC induction unit suitable for typical blacksmith work would cost; about $15,000 with all the items needed except the individual coils. Looks like Grant has come in at the right price point. |
| - Bob Jhonson - Wednesday, 07/19/06 12:55:51 EDT |
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i was reading the safty thing on here and activated charcoal cartridges seem to be good to use but do i really need one for the work i would be doing (weapons forging) i read the coal/charcoal page and it seems charcoal is a better choice for heating is this right or should i use something els (i need inexspensive and hi heat)or is gas the best o thank u for the recamendation on the book but is "new age of the anvil" good i was told about it by a midevil blacksmith at this renasants fair he was doing iron work mostly knives and spear tips |
| thomas mayhugh - Wednesday, 07/19/06 14:19:44 EDT |
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I bought a 90 pound anvil and face is marked quite a bit. Can it be resurfaced? Thanks, rusty |
| rusty - Wednesday, 07/19/06 14:43:43 EDT |
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Andrew: Yes, the resonant frequency from below curie to above curie can differ by as much as 20:1. Fortunately this machine has a range of 30 - 100KHz, which covers most of what we (blacksmiths) want to heat. As we talked about earlier, the machine automatically adjusts the frequency to the tank circuit (within it’s range). Lower frequency machines and higher frequency machines cost more. They build a lot of machine in the midrange and get economics of scale. The components used in my machines are ubiquitous. While a lower frequency would work on pieces ½ inch and over, it would not work on anything smaller. A higher frequency machine is more dangerous and has poor penetration depth. These are radio frequency devices and require FCC certification and shielding and a whole slew of things I don’t want to get involved in. Working with a little too high of a frequency only limits the depth of the initial heat penetration, the balance is by thermal conduction. With too low of a frequency, you can’t heat above Curie. Actually the machine does not need to know when the part reaches Curie. It only needs to resonate with it. As the permeability changes (for whatever reason), so will the frequency. |
| - grant - Wednesday, 07/19/06 16:26:31 EDT |
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Bob Johnson: Why thank you, Bob! Actually 5-10 KW is a little low, did they have a 15KW single phase machine? Most American machines I've seen in this size are three phase and cost a minimum of $20,000.00! |
| - grant - Wednesday, 07/19/06 16:30:52 EDT |
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Rough Anvil: Rusty, You want to do as little as possible to prevent thinning the face too much. An 18" belt sander used with a coarse belt (60 to 100 grit) works well and prevents making worse dings. A flap face wheel on a small 4-1/2" angle grinder can also be used but you need to keep it moving constantly or you can make dips. A big 7" HD angle grinder can also be used but should only be used by someone with lots of experiance as they can make an 1/8 ding as fast as you can say DING. I use all three when available. If you do not own any of these grinders then the 4-1/2" are the least expensive. There are some for less than $20 but they are often throw aways. If you remove 95% of the marks you will often just have places that are just discoloration that can be ignored. Many of these will "heal" from use. In fact, if an anvil has a lot of chisle dings they should be closed up by lightly hammering all over the surface BEFORE doing any filing or grinding. Do not have anyone weld on it or machine it. Some old anvils only have a 1/2" thick face and others that are solid steel the hardness is less and less as you go into the face. Many anvils have been permanently ruined, turned to junk, by folks that said they knew what they were doing. . . |
| - guru - Wednesday, 07/19/06 16:49:04 EDT |
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Rusty, Yes, No, or Maybe depending on information you haven't provided us. What type of anvil is it---cast, forge welded, cast iron with or without a tool steel face? The maker will help tell us this. How thick is the hardened face---if it has one? What kind of damage---how deep? If it is a traditionaly made anvil it has a hardened face of limited thickness and anything you do that decreases that thickness is moving that anvil toward boat anchor status. In general we suggest you go over the face with a belt sander or a flap wheel on an angle grinder---harder to not make mistakes with an angle grinder. Don't try to clean all the dings off, you just need a couple of inches in the sweet spot for most forging work. If the face is soft---see the anvil FAQ for the ball bearing test---You may want to try planishing it smoother before grinding. WARNING: There have been a number of people who have ruined anvils by clamping them down to a milling machine table and milling the top parallel to the bottom never realizing that they were *NOT* parallel to start with having been forged freehand using steam hammers. By doing so they have milled off large ammounts of the precious hardened face to make it parallel to the base that nobody cares about. If you *must* go this route clamp the face to the table of the mill and true the bottom to it and then flip it and mill the least ammount possible off the face. Welding on the face: if you have to ask about the proper method/rod to weld on high carbon HEAT TREATED steel you probably don't want to attempt this... Thomas |
| Thomas P - Wednesday, 07/19/06 16:58:50 EDT |
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Thomas Mayhugh, Have you read our "Getting Started" article and followed the links? New Edge of the Anvil is one we recommend and have reviewed. The review is old and needs updating with more images but it is a very good book. Charcoal and coal each have their advantages and disadvantages. Charcoal is very clean burning and you often do not need a chimney (just good ventilation). However, it makes dusty ash that blows around AND some grades make hot fleas that are almost as bad as arc welding sputter balls. Even in tropical countries folks using charcoal like to wear full covering (long sleaves and pants) to help protect from the fire fleas. The poping hot fleas vary according to kind of wood used. Dense resinous wood charcoal tend to be worse than good pine or oak. Good coal makes a hotter denser fire. Its smoke MUST be vented outside the shop. Coal quality varies greatly. Where with charcoal the only variability is a slight difference in density and the quantity of fleas there is coal that will almost NOT burn. Coal ranges from nearly pure carbon down to mostly slate or "oil shale". In hardness it varies from anthracite to peat. There is infinite variety and only the best is really suitable for blacksmithing. However, the best is VERY good and much more efficient than charcoal. Wearing a respirator mask in the shop 100% of the time can be expensive. The filters have a limited life even with fairly clean air and the masks themselves wear out. Wearing a respirator mask is also stressful ESPECIALLY in hot weather and can lead to other problems. In fact in most industry you must pass a specific physical prior to using a respirator mask. However, there are times when you absolutely should wear a mask. It is also best to have the correct filters for the specific job. They make combination particulate and activated charcoal filters but they are more expensive and can be a waste. Hazards consist of dusts and particles that can be removed by filter paper and fumes and gases that go right through filter paper and must be removed by the activated charcoal. Most hazards are not both and half a combination filter will get used while the other half does nothing. Identify hazzards and have a mask with flters for each. Also be sure to have spare filters. They do not last forever and as they clog the stress of using them goes WAY up OR you start sucking air around the edges of the mask. Also note that masks only work on clean shaven skin AND must be fitted to your face. Wearing a mask over a beard is pointless. Masks come in different sizes and those for a large round face or large head will not fit someone with narrow thin features or a small head. Also note that "hospital" type masks are just about worthless. While they WILL collect some dirt most of it goes around the edges. These things are designed to prevent spit dropletts from a cough or sneeze from being projected OUTWARDS, not to stop inward traveling dust. Unlike a respirator these actually work BETTER with a beard as the air going around the edges may be filtered by you beard. . . but do not count on it. |
| - guru - Wednesday, 07/19/06 17:17:51 EDT |
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Thomas M.: I do primarily weapons. As I stated earlier, the type of forge you want to use depends on your own personal preferance. There can be some other factors which influence your forge choice as well, such as if you live in an urban area and are going to be working in a backyard setting, coal forges tend to produce a great deal of smoke which may not be looked kindly upon by neighbors, also the availability of fuel sources and cost in your particular area. I know for me, coal is a bit more expensive and difficult to come by where I live. Now, you can make your own charcoal, which is about as cheap as it gets, you just need some scrap pieces of wood (I think hardwoods work best in this case). Now, the good thing about coal forges is you can build one for little to nothing, you just need some sort of container to hold the fire (break drum, or any thing like that) and a blower, which can be as simple as a hair dryer with the heating coil disconnected. Coal forges do take a bit more work setting up and preparing the fire for work however. They take some time to light and get going, and you have to know how to build the fire right and where to keep it for the maximum heat. Propane/gas forges cost a bit more to make, but are a lot more efficient (in most cases) and easier and faster to run. I built my forge out of an old propane cylinder that I first knocked the stem off, then filled to the brim with water to prevent an explosion (anyone who welds should know this, but) never attempt to weld or cut anything that has held flamable materials, even if you think it is clean, the porosity of the metal may still have some traces of the material left, and if you cut into that, or weld it, there is a high chance for an explosion, which will kill or seriously injur you. The only time it is safe to do something like that is if you have had the container professionally boiled out with acid and filled with an inert gas, or you completly fill the container with something like water so there is no air exposed in the container (but that wont work to well if you are trying to weld or flame cut. Just if you are using something like a cutoff wheel or something that sparks.) Anyways, after I cut open the cylinder, I made some openings in the front and back, a couple of holes on the top to recieve my burners, and hinged a door. Then I welded some legs on it and gave it a coat of high temp paint. Then I insulated the body with some kaowool, gave that a couple of coats of ITC-100 and dropped in my burners (atmospheric Reil design). Overall I think it cost me about $150 to build my forge, the insulation was the most expensive part (but I ordered enough to insulate about 4 or more forges, so its actually a bit less $ than that. Plus that is including buying a new propane cylinder to fuel it). So it will cost more to build a propane forge, and it will take a bit more work, but as far as the fuel availability, you can get it anywhere, and its not too overly priced. Plus, all you have to do to start it up and work, is open the gas, strike the flame, and let it heat up. Plus, its a whole lot easier to get it hot, my forge will get passed forge welding temp in just a few minutes (not sure how hot it runs exactly because I lack a pyrometer, but It is probably somewhere close to 2800-3000 degrees F). The propane also burns cleaner and you dont have to worry as much about oxidizing, burning up your piece in the coals or contaminating it, and no nasty smoke for the neighbors to complain about. So as far as simplicity of use, I would say you cant beat gas, but that is my own opinion and what works best in my situation. I will probably try to set up a coal forge later on when I get more time and after I have taken care of some other things for the shop I could use first. So, there is my views on forges. If you want some more details about how I built my forge, and what I used and/or some pics. Drop me an email. |
| TarAlderion - Wednesday, 07/19/06 18:01:44 EDT |
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Sandycreekforge, Bundling those semi-axles by welding will be pretty difficult. The alloys used in Class 8 trucks are a Chrome/nickel alloy with the addition of managanese to add fast deep hardening by induction. Welding is very difficult. Old axles, say 1960 or 1950 or even before may be 4140, also difficult to weld for this application. |
| ptree - Wednesday, 07/19/06 19:02:27 EDT |
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Copper in the forge: There may be some basis in science for keeping copper out of your forge. Liquid and vapor phase copper can penetrate steel at the grain boundaries. This weakens the grain boundaries and the steel can literally crumble apart. Copper in most electrical contact devices is usually very pure because, as has been mentioned, alloying lowers the conductivity of any pure metal. |
| quenchcrack - Wednesday, 07/19/06 20:47:12 EDT |
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Rusty, other than a little dressing with a belt sander, anvil repair should be done by someone who knows his welding and knows his anvils. It is quite common for people to want to repair their first anvils when in fact, as Thomas pointed out, its probably not necessary and once you get a feel for the work you will look at it quite differently. |
| adam - Wednesday, 07/19/06 22:36:11 EDT |
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I have plates of pure copper and pure titanium either brazed or high temp soldered together. I'm trying to get them apart. How hot will I have to get the solder to "make a parting of the ways" so to speak? Will a hand held propane torch (benzo)do the trick? It's enough copper and Ti that i couldn't carry them in one trip and the $ from recycling is going into my forge fund. thanks chris |
| Chris R - Wednesday, 07/19/06 23:16:08 EDT |
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Chris R :It all depends on how big they are and what EXACTLY was used to join them. Copper conducts heat really well, so there must be enough heat to get the entire thing hot at once. Silver solder will take red heat, brazing will take a brighter red heat. If they were solid state bonded You would have to melt the copper off, probably not practical. What will the scrap guy give for them "AS IS"? If You could get a forge of any kind together as a heat source, You might stand a chance at getting them apart, A small propane torch alone probably won't do it even with a makeshift enclosure unless they are really small. |
| Dave Boyer - Thursday, 07/20/06 01:54:24 EDT |
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I am looking for information on making a jew's harp, jaw harp, juice harp, trump. I would appreciate any information and help. Thanks, Chris |
| Chris Brown - Thursday, 07/20/06 08:13:58 EDT |
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Jews Harp: Chris, There are books on making folk musical instruments and I THINK this one is covered. Sadly my books that would have it are packed for moving and are several hundred miles away. Information for making musical instruments in general is fairly rare. The best places to find it are university libraries where they have a music program. The best (world wide) is the music library at the University of Virginia in Charlottesville, VA. They have a better collection than the Library of Congress which is the second best in this regard in the U.S. The UVA libraries are open to the public but their schedules are erratic being closed during exams and holidays. CALL before making the trip. The music library is seperate from the main library and much easier to use if not a little difficult to find (sub basement of the music building). If you are intrested books on making musical instruments this collection is worth traveling any distance. What makes the UVA collection different is that they have a buying program to purchase all books on this subject no matter where they are published. The Library of Congress collection is made up entirely of books supplied via copyright applications and as gifts. MANY forign publications do not make it there unless they are copyrighted seperately in the U.S. I have a number of books on this subject that are not in the LOC. Books of this nature are a lot like some of the books in our field and others that come into print one time in a limited number and that may be the last. Folks that are serious buy them when they can. Libraries often have them but if they are not used they get culled so the only choice is private and special collections (such as UVA's). |
| - guru - Thursday, 07/20/06 08:57:28 EDT |
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Grant, May I suggest a useful feature for your induction forge? Because your controller is already tracking the resonant frequency of the work coil, why not detect its abrupt rate-of-change as the work piece passes through its Curie temperature and signal the blacksmith (say with a sound)? This would be helpful for heat treating purposes, if you are using the Curie temperature to indicate when to quench something. At the least the user would get continuous training in matching the heat color with the nonmagnetic point. |
| Walking Dog - Thursday, 07/20/06 09:01:20 EDT |
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Thanks for the information guru. I will check the local university. Thanks again Chris |
| Chris Brown - Thursday, 07/20/06 09:02:00 EDT |
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Another copper question: What precautions should one take against copper oxides when working with that metal? Thanks |
| adam - Thursday, 07/20/06 09:04:08 EDT |
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Chris, If you do not find something let me know. I had planned on leaving my musical instrument books packed up but I get numerous questions on some related subjects. Next time I am at "home" I will pick up those boxes. |
| - guru - Thursday, 07/20/06 10:25:19 EDT |
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I have a wrought iron decorative rack that has a mirror in the middle, a shelf below the mirror and hooks (for hanging coats or whatever), I had to have a iron bar attached to this piece in order to hang it on my wall (so it could be attached to the wall into the wall studs), now how do I get the dark color (flat blackish/grayish color) in the new iron? |
| Roxann Foster - Thursday, 07/20/06 10:26:50 EDT |
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Copper, Copper Oxides: Although we are surrounded by copper items, work with wire, wear copper jewelery the metal and its compounds are toxic if ingested. If you burn copper in the forge it may not prevent a forge weld but it may poison you. Generaly the problem is with grinding or buffing brass, bronze or pure copper. This puts lots of fine particles of the metal in the air which you breath, thus it gets in your mouth and lungs, you ingest it and should be able to taste it. That nasty metalic copper taste is a warning that you should have been wearing a filter respirator. Copper is not as toxic as other metals like cadnium or lead but it IS a heavy metal that can cause problems if you absorb enough of it. In general you can work it as much as you want, just be carefull when making fine particles or dust. |
| - guru - Thursday, 07/20/06 10:38:56 EDT |
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Roxann, The general color of forged iron and steel is from the surface oxidation called scale. This is a blue grey when fresh and dry and becomes a dark grey-black when oiled or waxed. Scale occurs when the steel is heated to a red heat or greater (1500°F or more). Your best bet is to clean as sand the metal surface and then paint it. Flat black spray paint will not match but will be close. Otherwise you can let it rust. Light rust when waxed makes a dark brown similar in tone to scale. On very old pieces of unpainted ironwork the finish is often a combination of rust and scale. When places are scratched or the scale rubbed off the steel will rust. Oiling or waxing darkens the rust and it nearly blends into the waxed scale finish. Scale and rust (browning) are both natural finishes but the require constant maintenance by cleaning and re-waxing. For practical purposes and low maintenance paint is better. |
| - guru - Thursday, 07/20/06 10:49:48 EDT |
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