WELCOME to the anvilfire Guru's Den - V. 3.3

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 October 16 - 23, 2011 on the Guru's Den
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Mortar : I am not a builder but I have heard that concrete can gradually harden ( cure )over a period of years. I can see where anchor bolts should only be placed in aged concrete.
   Mike T. - Sunday, 10/16/11 00:12:10 EDT

Mike : That's true, but it does reach 90% of it's rated strength and 80% of it's ultimate strength in about 30 days.
   - GRANT - Sunday, 10/16/11 02:50:13 EDT

Anchor Bolts : I was doing some thinking. When putting up shelves on walls, etc. There are bolts that have a butterfly ( I don't know what its called ) on one end, you fold it up push through the hole and it flaps open, locking tight once the bolt is tightened. It looks like something like this would work if they were hardened steel.
   Mike T. - Sunday, 10/16/11 05:59:54 EDT

Anchor Bolts : lately I've been using new type bolts that thread into the masonry 3/8 hole...3/8 bolt.... no expansion....no broken bricks
   larry - Sunday, 10/16/11 07:56:29 EDT

Concrete generally does not reach full rated strength for a year and improves over a period of time longer than a year.

Not all concrete is equal. . . When good limestone aggregate is used the hardness is not uniform but its not bad. I've had the misfortune of working with concrete made with hard granite (a vault) and quartz (a dam). The very hard aggregate makes it VERY difficult to make a hole, much less a straight one.

In the US most bricks are pretty good but the vast majority have lightening holes in them which makes them difficult to place anchors in. As Rich pointed out, I've seen quite a few bricks that were either broken OR their mortar joint broken loose from attempts to anchor things to them.

When we were setting a lot of anchors we used a shop made nozzle that fit a vacuum cleaner and air compressor. Pressurized air blew out the hole and the vacuum kept the dust from spreading everywhere. After the first blow out we would rinse with water then blow out again. Clean holes make a BIG difference.

When anchoring machines we often ended up using shim stock and electrical tape to make the anchors tight. When I was building my shop one sill for a central wall used concrete anchors. Only about half pulled down tight on 6 month old concrete so I ended up putting a LOT more anchors in than I planned. The exterior walls used long bent leg anchor studs set when the concrete was poured.
   - guru - Sunday, 10/16/11 09:34:53 EDT

Molly or Toggle Bolts : Are what those "butterfly" anchors are for. They are generally for use in hollow walls and require a huge hole. These work well in some situations but have a bunch of problems.

1) In hollow walls if you remove the screw the toggle falls down into the hollow. . .

2) Unless the toggles can both open it will not work. My luck has been that the holes I drilled were almost always in a corner next to a stud and brace or too close to the divide in a concrete block. . . I ended with a big hole to patch and needing to use a different type anchor. . .
   - guru - Sunday, 10/16/11 09:50:02 EDT

Dutch Crown (pot rack): I would like to see or get some information on making a square
or oval dutch crown. The size will not matter as i can modify it to suit.THANK YOU.
   robert - Sunday, 10/16/11 10:55:03 EDT

Pot Racks AKA Dutch Crown :
Robert, These are infinite in design and variety. Small ones are 16 to 18" in diameter and have 4 to 8 hooks. Large ones are custom made to fit over a kitchen work station or island and require a truck to move. Some use hooks riveted in place, some sliding (adjustable hooks some both.

Try google.com, dutch crown iron

Small round pot racks usually have 4 curved arms making them look like a crown. These are most often riveted to the circular band which is made of 1/8" x 1-1/2" or 2" (2-4mm x 30-50mm) stock. A nice design is to forge hooks on the four arms so there are four fixed hooks and then extra sliding hooks can be added. I also like a central hook to hang S-hooks from. I also used central hooks on hanging candle chandeliers for the candle snuffer to hang from. I also made one with candle holders and copper reflectors.

Depending on the size and shape of the rack there can be one to four mounting points. Some hang from chain, other rigid brackets. When chain is used I like to use hand made chain designed to match the overall style.

There is a ton of things you can do to decorate or make these a fine work of art rather than the common mass produced type. Artistic texturing or incising, piercing, additions such as leaves, pine cones, animals, fluer de lis. . .
   - guru - Sunday, 10/16/11 11:59:06 EDT

Poor Man's Forge : Hello everyone. I was wondering if I could get some feedback on one of my ideas. I want to make a forge using a brake drum for the hearth. I wish to place this on platform. I am thinking wood, if I can not find a good piece of steel. If I use wood and place refractory cement on it would it hold up. I plan to put up to 2 in. on it. Here is a rough sketch.
Bl Wood lB
Bl ooo lB
Bl o o lB
Bl o o lB
Bl ooo lB

I am planing to get some soft fire bricks to place around it. I hope this is understandable, if not let me know and I can send some more info.
   Walter N. - Sunday, 10/16/11 18:31:07 EDT

That sketch didnt come out right....
   Walter N. - Sunday, 10/16/11 18:33:54 EDT

My wife looked at some shoes today. The label described them as "anti-gravity" shoes that made you feel like you were "walking on air." That much wasn't so bad. But it went on to say the soles were foamed with "lighter than air nitrogen." Technically true, I guess, but really . . .,
   Mike BR - Sunday, 10/16/11 18:37:52 EDT

Mike, Its like "Titanium Steel" (unobtanium) blades sold by the charlatans in "our" world. . . And then the Rosie O'Donnells of the world that could get away with statements like "fire cannot soften steel" in reference to the World Trade Center towers crumbling. . . EVERY time she opened her mouth on that one someone should have called her on her gross ignorance. But the interviewers were equally ignorant as are most of the buying public. . .
   - guru - Sunday, 10/16/11 20:17:38 EDT

Forges and Wood :
Walter, The first thing to remember is that refractory cement and refractory bricks ARE NOT insulators. They are heat resistant but conduct heat very well. In an hour or so they will conduct enough heat from a forge to char wood.

The radiant heat from a forge will set fire to wood and melt plastic up to a foot away. That includes parts of the tuyere which often get fuel inside and glow red as well as the fire pot. So beware of radiant heat from the pipe sticking through the wood.

A true "poor man's forge" in a wooden box is insulated with dirt and lined with clay (often bonded with a little manure).

pit forge
Side Blown Pit Forge

A pit forge is traditionally side blown but can be bottom blown with a little hardware and effort.

ASCII Sketches in HTML generally do not work unless space codes are used to replace spaces. This is a windows (where spaces are less than a character wide) and browser issue where more than one space is ignored. I type two spaces between EVERY sentence. But HTML ignores the second and every following space. . .
   - guru - Sunday, 10/16/11 20:39:58 EDT

Poor Man's Forge : My first "Poor Man's Forge" was a brakedrum set into the top panel of a junked clothesdryer. The dryer guts were already completely removed, Essentally it was just a sheetmetal box that I cut a hole into the top of to set the brakedrum into. Initially te brakedrum was too deep for my small scale knifemaking, But I changed it to a brake drum&disk from the rear of a Volvo car. The drum portion being about 2' deep X 6-7" dia worked great, the disk part was the flange the thing set into the sheetmetal hole. I made a "rockerball" out of a disc of 1" plate steel, Placed into the tyere on a pin sort of like a stovepipe damper. It was just jiggled side to side to clear the tyere, never fully rotated.

Good luck with your set-up. As Guru and everybody else will repeat a forge can be a simple or elaborate as one can envision, But a brakedrum is a great poormans beginnings.
   - Sven - Monday, 10/17/11 01:06:34 EDT

Old Appliances :
Parts from old appliances can be used for all kinds of things. In this case Sven is just using the shell for a stand. All that enameled (ceramic coated) steel is quite durable. Washers and driers often have motors that can be repurposed and the drums can be used for light tumbling and parts washing. Old hot water heaters have sheet metal exteriors that can be reused as well as the steel tank. Old kitchen stoves are handy as-is in the shop. Generally a "bad" stove only has a one inoperable burner or a failed timer. Many are replaced for mostly cosmetic reasons. . .

The great thing about these items is that you may be PAID to haul them off. . .
   - guru - Monday, 10/17/11 01:46:43 EDT

Titanium Steel : I have seen several high dollar knives with blades coated with titanium to enhance corrosion resistance. Hmmmmm....why do they plate it onto stainless steel? Why not on carbon steel where it would really help? Like the knife set I saw advertised years ago for "Molecular Stainless Steel". Nope. Metals have crystals, not molecules. Just more advertising BS.
   quenchcrack - Monday, 10/17/11 13:10:59 EDT

Anchor Bolts : I was thinking that a person could make their own anchor bolts. Cut a slot down the middle of the bolt, drill a hole through the side, then drill a hole in the toggle, place the toggle in the slot parallel with the bolt, then insert a lock pin ( peening each end.) Have the toggle off center enough so when it goes through the wall, it will swing open.
   Mike T. - Monday, 10/17/11 14:22:12 EDT

Anchor bolts. : I would not suggest too much time making this type anchorbolt as they are made commercially at a modest price.

A good features of this type is they can be finessed back out of their hole provided they had not been tightened too much so the toggle is distorted, and the drilled hole needs to be only the bolt diameter.
   - Sven - Monday, 10/17/11 15:28:03 EDT

Toggle Bolts : I've had the same problems with these lever toggle types as with molly bolts. Some will work, but then you hit locations where they will not. 50/50 is the best results I've had. I've also lost them inside walls. . .

As Ries pointed out, you need to approach every anchoring job with a variety of fasteners.

The self drilling self taping narrow thread type fastener works very well when the holes do not go all whopper jawed. .

   - guru - Monday, 10/17/11 15:44:21 EDT

Sven : Thanks for your input. I have never done any construction work, but come up with ideas from time to time.
   Mike T. - Monday, 10/17/11 15:44:50 EDT

anchors : 30 yrs. of construction says Epoxy, Hilti, Core drill is the best bet 95% of the time
   - bam-bam - Monday, 10/17/11 16:40:28 EDT

Hilti : bam-bam....what is a Hilti ?
   Mike T. - Monday, 10/17/11 17:02:33 EDT

status : getting better, can work longer periods now. able to keep forge open.
looking at a road trip in future, anyone open for a forge visit?
i'll bring my hammer.
   - Geezers' Forge - Monday, 10/17/11 17:03:27 EDT

There are, at any time, a bunch of Hilti MD2000 guns on ebay for between 20 and 40 bucks. This is a two tube caulking gun, which takes the standard size concrete epoxy twin tubes.
Its well worth the money, will last you a long time, and works really well. Why mess around with molten lead or wrapping foil, or various other complicated fussy things that may or may not work?
Just buy the damn gun.

As for toggles- I have used these things called Toggler Snaptoggles for the last 15 years or so- they are about ten times better than the old style toggle bolt- they use a plastic carrier to hold the parts together til they are installed, but have a much smaller, flat, toggle assembly, and you install the captive nut part first, and it stays in the wall, even if you take the bolt out.
I have hung 4' x 8' 400 pound fence panels on stucco columns using 1/2" x 13 tpi versions of these- and they work really well. They dont fall off inside the wall, they are very sturdy, and 1/2" is a good bolt size for hanging big stuff, which I often do, in walls where there is NOTHING but chicken wire, mud, and a lot of air...
   - Ries - Monday, 10/17/11 17:06:17 EDT

Hilti is a brand name for some of the best industrial power tools, and concrete working tools, such as drills, grinders, saws, and yes, anchoring systems. They dont sell it at home depot, you have to go to a real industrial tool store. Its top quality industrial stuff, and worth every penny. Easy to buy online, though- I think even amazon has it, certainly its on ebay.
   - Ries - Monday, 10/17/11 17:08:06 EDT

Hilti Anchor : I probably spelled it wrong. It is a type of masonry anchor system. The health of my brain stops me from giving all the tech info.
GURU or PTREE can explain better right now.
I will defer to them.
   - bam-bam - Monday, 10/17/11 17:09:51 EDT

MIKE T. : As i answered, RIES posted the correct anchor
thank you.
   - bam-bam - Monday, 10/17/11 17:13:34 EDT

SEE, I still got head probs. can't tell answer from anchor.
   - bam-bam - Monday, 10/17/11 17:15:07 EDT

bam-bam : shoot, I didn't even notice the wrong word until you pointed it out. I guess we are both a couple of rednecks. Jeff Foxworthy would be proud of us, even Larry the cable guy. ha ha
   Mike T. - Monday, 10/17/11 18:10:56 EDT

Actually some of the Home Depots here (D.C. area) *do* carry a line of Hilti products.
   Mike BR - Monday, 10/17/11 18:44:26 EDT

I am not fighting any recent brain injuries, but still have trouble with words often. No biggee. You got the right name as if it was pronounced, it would sound right.
I think it was Mark Twain who said something like " Only a very small minded man can think of only one way to spell a word"
Continue on the path to better with my best wishes.
   ptree - Monday, 10/17/11 18:47:03 EDT

Spelling : I thought it was Andrew Jackson who made the quote about spelling.

"It is a damned poor mind indeed that can only think of one way to spell any word" [or something to that effect]

He gave Us "OK" as an abreviation for "All Corect".

Jackson may not have been the first stupid president, and for sure not the last.

By His judgement I must have a superior mind, as I don't always spell a word the same way in the same post.
   - Dave Boyer - Monday, 10/17/11 22:26:10 EDT

Epoxy System guns : The double tube gun I bought over a decade ago was a heavy duty model that cost about $50 at the time. It is beautifully made and there is probably nothing made like it today. It was purchased for one job and I've only used it a couple times since. But when you need to fill a hole with industrial epoxy these are the way to go.
   - guru - Monday, 10/17/11 23:15:45 EDT

Spelling :
Mine has always been pretty imaginative. . . But the spell check in firefox has helped a LOT. If you have spelling issues and you are not using firefox then you are using the wrong browser. . .

My primary editor does not have full time spell check so I have to run it when I remember. . .

Over the years of running anvilfire I've exchanged a lot of letters with folks in other languages and read translated articles. One thing this teaches is that machine translators do not work well with misspelled words and bad diction in any language. Many tools for spell checking and such are much better and available in English than other languages. However, this is changing as computers become more commonplace world wide. Machine translators are also now spell checking prior to translation.

If you think "foreigners" speak English funny and make dumb mistakes remember that YOU would sound the same or as peculiar to them when you try to speak THEIR language.
   - guru - Tuesday, 10/18/11 00:06:17 EDT

anchors : thanks all - guru / tim / paul / larry / mike / rich and anyone I've missed.

Good food for thought. Great to be able to 'check in' with others
   bob the blacksmith - Tuesday, 10/18/11 10:54:50 EDT

castable / cast carbide : I experimented a while back with a cast carbide piece - 1" thick

Well it has excellent chemical resistance but but but its thermal storage makes it like a solid 1" slab of steel - takes a long time to heat up. Same is true for castable and ramable.
Also be careful about 'washes' they can pull down the blanket fibers from walls and roof.

Best so far was spreading 'softened' castable over blanket 1/2" usually suffices.

Best is to take great care with those fluxes and not poking the walls with the work (easily said haha!)
   bob the blacksmith - Tuesday, 10/18/11 11:06:14 EDT

Quantum levitation : You gotta watch this!

   - grant - Tuesday, 10/18/11 14:46:21 EDT

Refractory coatings : I've had problems with coatings pulling the Kaowool apart myself, and have come to a couple of realizations about it. First thing is, Kaowool is used for its insulating properties and you have to keep in mind that it is NOT a structural material. If you need a structural material you can either use rigid refractory board (Kaoboard or similar), or use a rigidizer treatment on the Kaowool. This has to be done prior to adding a topcoat like ITC-100.

Trying to make a stronger roof by piling a lot of coating on the surface of the Kaowool is a folly - the Kaowool will simply separate, the coating fracture due to thermal stress and the whole works falls down. Been there, done that. You need to use the rigidizer first to bind the fibers of the Kaowool together and then add the heavy coating.

I've used other coatings besides the ITC-100 and they haven't been as good. Cheaper, yes. As good, definitely not.

I am about to reline my primary forge very soon. Waiting on my order of ITC-100 to arrive, which should be here tomorrow. I'll use the rigidizer, allow it to dry thoroughly, and then apply a normal coating of ITC-100. Once the ITC-100 has dried completely I'll slowly bring it up to 600°F to get rid of the chemical water and then fire it at 2400° to make it refractory. Following that, I'll add another coat, (possibly two), following the same process. I doubt that I'll add a third coat, since doing so only adds weight and doesn't really add any appreciable strength. Weight without strength is no benefit, obviously.

My forge has sidewalls that are firebrick to about 3" up from the floor. That handles most of the abuse and the ceiling gets very little.

Castable refractory, kiln shelf (either mullite or silicon carbide), hard firebrick; all of these are poor insulators and have high heat sink capabilities. However, they're all fair to good about handling flux and force. Lightweight refractories aren't. The heat that it takes to get the dense refractories up to forge temp isn't wasted by any means - you get it back when it radiates to the steel you're heating. Forges do most of their heating of the steel by radiation and only a little by conduction. Air is a poor conductor. Knowing this tells us a couple of things.

The more radiant heat you have, the faster your steel will get hot. Radiance is a function of area and temperature, as well as the "black body" radiation capability of the material itself. ITC_100 is a really good radiator, something like 95% IR radiance. That's why it is such an effective forge coating. What else can we do to increase radiance? That's easy - add surface area. How to do that within the confines of a given size of forge chamber? Make the surfaces of chamber "larger" by making them corrugated!

If you take a piece of typing paper and accordion fold it in 1/2" increments and then spread it back out until it is about 1/3 to 1/2 it's original width, you can see that you have just crammed 92 square inches of radiant area into a 33 to 46 square inch space. Apply that concept to your floor and you have accomplished two things - you've doubled (or better) the radiance, while allowing convective flow beneath your steel. The convective flow keeps the floor hot so it can radiate that heat to the steel.

So, there's a few things to think about on gas forge design. Believe me, they really make a difference. I have a 950+ cubic inch forge that gets to 2500°F on only two small burners, and will maintain that heat with only ONE burner running. If I can do it, you can do it, because I just told you how. (grin)
   Rich - Tuesday, 10/18/11 15:21:15 EDT

bob the blacksmith : As there are may "carbides" I presume you're talking about silicone carbide. Are you just using it as a floor?
   - grant - Tuesday, 10/18/11 15:24:15 EDT

Kaowool Construction :
Many industrial furnaces and kilns are made with kaowool fiber panels that hold up fine for years of operation. However, they are using techniques much different than popular forge construction.

The refractory panels are made by either fan folding or strip folding the kaowool. A stainless steel wire is placed in the fold. Short pieces of wire are looped around the long wire and pushed out the back of the kaowool at the fold. These strips are then tied by the wire to expanded metal held in a frame. Installed panels are coated with ITC-100. Insulated furnace ceilings over a foot (+4 dm) spanning 20 feet (6 meters) or more are built this way.

This construction is much stronger and durable than flat (laminar) refractory blanket construction. The stainless wire is near the cooler exterior or cool face of the panel where the temperatures are less than oxidizing for the wire. In thin panel high temperature construction Inconel, Nickle 600 or Nichrome wire wire may be used.

Contrary to what one would think the higher the density of the kaowool the better the insulation properties. While kaowool is sold in different densities the controlling factor is how it is held in place. Common 6 Pound Per Cubic Foot (166 g/cm3) kaowwol will fluff up 1.5x its thickness to 4 PCF and can be easily compressed to 3/4 its rated thickness to 8 PCF. So installation and construction methods determine not only the strength of the panel but the insulation value.

Applying heavy coatings to kaowool is counterproductive due to its low tear strength. If the coating cracks or breaks up it will easily fall off.
   - guru - Tuesday, 10/18/11 16:49:15 EDT

Refractories : Refractories are not totally impervious to heat. Like steel they also lose strength at high temperatures and can sag.

Water set refractories (castables and ramables) are not nearly as strong, durable or chemical resistant as fired refractories. Good refractory brick is much better than castable. You just have to design around the standard sizes.
   - guru - Tuesday, 10/18/11 17:01:27 EDT

Textured Forge Floors : I've thought about a ribbed forge floor for some of the same reasons as Rich. However, I'm not sure about the increased surface area theory. The angles of the surface would disperse the radiant heat and the angular radiant heat. On the other hand an arched roof is longer therefore has more surface area AND the shape would focus the radiant heat at its focal point.

The ribbed floor has several advantages. One, as Rich noted, the hot forge gases can circulate around the work. Another is that the grooves if sufficiently sized could make it easier to pick up work off the floor. They are also places for scale and flux to collect which could be bad or good.

Another forge floor shape that would give a similar effect is a waffle texture.

The only reason I considered these shapes was part of casting a floor block for a certain forge design. Cast in a wood mold the textures are easy to make in wood then finish well. Ribs are easy, waffles more little pieces.
   - guru - Tuesday, 10/18/11 17:47:15 EDT

I'd think an accordioned floor surface would radiate the same amount of heat as a flat one. One way to look at it is that the heat radiated from the rest of the forge would be spread across a larger area, so any given unit of surface would absorb less heat. Less heat absorbed means lower temperature means less heat radiated back.

Of course, an area of refractory that sees less radiant heat will also lose less heat by conduction to the outside. But flattening the accordion and using using the extra refractory to make an extra layer of insulation would also reduce heat loss by conduction. I don't know which would be a more effective use of refractory.

I suspect that an average gas forge loses most of its heat to exhaust gasses, so this may be largely an academic exercise anyway. Whatever happens to the radiant heat inside a forge, heat loss can occur only through the forge walls or from the exhaust (aside from radiation through doors or other openings). The walls on any forge with decent insulation take quite a while to heat up, and don't get *that* hot. So I don't think all that much heat gets out that way.
   Mike BR - Tuesday, 10/18/11 21:34:48 EDT

I should clarify that I meant the *outside* surface of the forge walls don't heat that much. The inside surfaces get pretty hot pretty quick!
   Mike BR - Tuesday, 10/18/11 21:38:58 EDT

External Forge Temperature :
The first gas forge I built was a trough type and had a fire brick lining inside a 10ga steel plate box. The ends of the forge had the bricks turned on edge so there was 2-1/2" of brick then the steel plate. The rest was all 4-1/2" thick. The exterior got VERY hot but the ends where the brick was thinner got so hot you did not want to get withing several feet of the forge. I suspect temperatures just below 1,000°F on the ends. It was so uncomfortable working near this forge I sold it without the burner to a fellow that thought it would make a good barbecue. . .
   - guru - Tuesday, 10/18/11 23:02:23 EDT

Anchors : If you are putting in a lot of anchors the same size it is worth making a special tool.
Take a small hammer head suitable for knocking the fasteners into the wall. If your hole is the correct size they will need a slight tap but no more. Weld a piece of pipe into the head to act as a handle. Then weld the correct size socket for the nuts used into the other end of the handle. The heard makes an excellent grip which is big enough to turn to tighten up the nuts. You have an excellent combi tool.
Don't use the steel handled hammer for any serious amount of hammering of course.
BTW this is my world patent so after making the tool send me US$1,000;-)
   philip in china - Wednesday, 10/19/11 00:23:56 EDT

Refractory Board : I saw where it was mentioned and thought of something. The holes in a honeycomb are actually octygons, but for forging purposes, can be called round. When making a propane forge, why not cut angles in the board and fit the pieces together in an octygon shape ? Looks like it should work ? I have never used board, does it need to be coated with anything ?
   Mike T. - Wednesday, 10/19/11 02:06:19 EDT

Honeycomb and Refractory Board :
Mike, Honeycomb made by bees is hexagons. Hexagons fit together, octagons do not. Time to do some drawing. Making hex OR octagon boxes from material with any significant thickness requires careful angular cutting and joining.

Prior to some modern DIY pipe forge designs using refractory blanket, hard refractory lined gas and oil forges were rectangular. If they were very large they might have an arched roof. The only purpose for a round forge is that it was a quick and dirty method of construction. It has all kinds of problems and solves only one, the shape allows self supporting laminar construction with refractory blanket.

Refractory board also has problems. One is expense. 1" board retails at $15/sqft. or more. Individual 23x36" sheets must be sandwiched between two sheets of plywood for shipping thus doubling the product cost AND chipping cost. In bulk a case of six sheets costs about $800 retail. I say "about" because its been a long time since I purchased any. We were going to carry it in our store but due to the shipping logistics we gave it up. We've considered selling cut pieces (12 x 12 and 8 x 12) but the cutting adds a lot of cost.

Besides the expense it is messy to cut with a saw and is best cut with a knife. This requires deep scores on both sides of the board before breaking. While it would seem ideal for a forge roof the board loses strength when hot and sags. Thus on a large forge it must be anchored in multiple places. This is also problematic.

Refractory board is like all light weight kaolin refractories in that flux and scale attack it and rapidly destroy it. Its surface also breaks down when exposed to oxidizing conditions and produces dust. So it should coated with ITC-100 as well.

Industrially board is used as an insulation behind hard refractory brick panels and shelves. It works well in these applications. When used for an exposed surface it is stronger than blanket but it is still susceptible to mechanical damage. Due to it's compression strength it makes a good insulation under a refractory brick forge floor. NC-Tools used to use a piece of 1" board under a thin fired refractory floor block. I've thought about using it under a split brick forge floor in a demonstration forge I am building but did not want to use materials that we are not selling.

Costs dictate trade-offs and compromises on most things we build so no design is ever perfect.
   - guru - Wednesday, 10/19/11 09:25:29 EDT

old world anvils : are they any good ? are they worth the money ?
   greg colman - Wednesday, 10/19/11 12:00:43 EDT

MikeT your "One way to look at it is that the heat radiated from the rest of the forge would be spread across a larger area, so any given unit of surface would absorb less heat. Less heat absorbed means lower temperature means less heat radiated back."

seems to be based on their being a limited amount of heat going into the forge. Every forge I know of runs on excess heat being wasted out the openings so the entire convoluted surface can be at the same heat and not at a lower temp.

   Thomas P - Wednesday, 10/19/11 12:58:29 EDT

Old World Anvils : Greg Coleman, when I bought my 75kg double horn, they were under $400 and I think that was a bargain. They are good anvils but if you are a pro smith, you might want to go with a forged anvil. I think that will last you longer if you beat on it every day. If you are a hobby hammer, they will outlast you.
   quenchcrack - Wednesday, 10/19/11 13:03:50 EDT

File metal : Have a friend who wants to make a draw knife out of an old file. He annealed the file (24 hours in vermiculite) and started grinding off the teeth. Going VERY slow.

Do they ever make files out of air hardening steel?
   Rudy - Wednesday, 10/19/11 13:37:33 EDT

Rudy, High carbon steel hard OR soft grinds about the same. Most people making blades out of files by stock removal leave them hard, shape the blade then temper to about a spring temper. How fast or slow it goes is all in the type of grinder and grit used.

The critical time for the anneal is the first 5 to 24 minutes. The longer time for alloy steels. There is also a heating soak time of a few minutes or longer at just above the transition point. If the steel is not heated properly then gotten quickly into annealing medium it may cool too fast and not be annealed.

Air hardening alloy steels are much more expensive grades of steel than files are made of. Files are generally something like SAE 1095 but when using recycled steels Junk Yard Steel Rules apply.
   - guru - Wednesday, 10/19/11 14:17:50 EDT

Energy generation : I notice you had a thread going on alternative et al energy generation.

I probably shouldn't admit this but I spent 20 years as an engineer w an electric (only) utility. Since I was the only engineer they had that was really good w words I got all the perpetual motion and similar nut jobs that showed up.

In most cases, (except the perpetual motion) they were right AND wrong. What they knew was correct. What they didn't know was an idea killer - or at least a major complication.

I can't say anything posted above is WRONG, but if anyone is interested, I can point out a few common misunderstandings.



   Rudy - Wednesday, 10/19/11 14:38:41 EDT

My main complaint about Old World Anvils is with the exception of one pattern (the Peddinghaus copy) they are all butt ugly as are MOST of the cast anvils being made today. Making a cast anvil beautiful is dead easy compared to making a forged anvil. For the cost of the patterns and the anvils I think it is criminal for them to be ugly. It is a waste of effort, steel and money.

Cast anvil patterns should have no creases, any decorative features should be sharp and crisp, hardy hole locations should be where they are the strongest NOT where they are easiest to make. Copies of historical types should look like the BEST of the type not cartoon versions of the worst.

Patternmakers ARE NOT anvil designers yet most of the current cast anvil shapes were dictated by the foundry and patternmakers. It is a case of the tail waging the dog.
   - guru - Wednesday, 10/19/11 14:50:27 EDT

DIY anvil : I've recently been taking classes in blacksmithing and I am wanting to set up a forging area in my garage. Right now I'm working on how to get an anvil and making my own seems like the best plan.

Reading through the articles here, I was struck with an idea, taking one of the cast iron ASO's and welding a tool steel plate on the face the step and around the horn.

Would this work, or would I be throwing good money after bad?
   Horuke - Wednesday, 10/19/11 15:39:41 EDT

No, it won't work. Too many reasons to list.

For what a cast iron junker costs new you can other find a very reasonable old used anvil. A beat up, swayed chipped and down right SAD looking old forged anvil is an infinitely better tool than an ASO.
   - guru - Wednesday, 10/19/11 17:19:29 EDT

dutch crowen : i would like enformation on this subject
   rnhulett - Wednesday, 10/19/11 17:31:56 EDT

Rudy; a possible problem with annealing is that smallish pieces don't have enough heat to start with to overcome warming up the vermiculite. A trick to get around this is to heat up a larger bar with the file and bury them both in the vermiculite so that the large bar can be a "heat donor" to the system.

My question is "what is he grinding with?" Some things are a whole lot faster and easier than others!---I have a student who's doing his first big blade and I've had him using several different abrasive set ups so he can learn what works best for him!

   Thomas P - Wednesday, 10/19/11 18:06:06 EDT

High Speed Steel : I read that razor blades are made out of M4 steel. Since they are so sharp, would something similar to M4 ( M2-M3 ) be suitable for making skinning blades. The reason I said M2-M3, I have never found a listing for M4 for sale. If it would be suitable, how would it be forged, heat treated, tempered etc.
   Mike T. - Wednesday, 10/19/11 18:09:03 EDT

dutch crown: Please specify, I assume you mean the one for hanging pots and not the one for the Netherlands royalty. But you don't tell us if you want suggestions for size, materials, how to construct one, how to mount one, how to finish one.

Instead of asking everyone to write a several page post that might not even cover what you want info on, please ask detailed questions!
   Thomas P - Wednesday, 10/19/11 18:10:00 EDT

Old Anvil : Horuke,

Good equipment is nice, but hardly necessary for the beginner.

A (possible apocryphal) story is told about the hippie who took up blacksmithing and could on afford an old junker w a chip out of it about the size of a grapefruit. Years later when he had a little money (probably from his day job) friends asked why he didn't get a new anvil. His supposed response "Are you crazy? That chip is too useful!"

Have fun. You're starting a long journey and don't be afraid to ask before spending money. We've ALL thought we could beat the market at one time.
   Rudy - Wednesday, 10/19/11 19:12:20 EDT

Annealed file : mhulett,

Yeah,we thought of that and did include a couple pounds of big scrap wire to the file. We were not particularly careful and might have just done it wrong.

The Sutter's Mill Forge has no power tools so we are trying a 2 foot diameter, foot pumped, sandstone grind wheel (don't ask) and some harder stones hand cranked.

Unless we REALLY want to be true path, we may just have to bite the bullet and go down the hill to the park maintenance shop.
   Rudy - Wednesday, 10/19/11 19:19:07 EDT

Thomas I (and not Mike T) was referring to radiant heat. There's certainly plenty of hot air in forge, but the floor's only going to see a given amount of radiant heat, whether it's flat or textured.

And a surface that sees both hot air and radiant heat's going to be hotter than one that just contacts hot air (or hot air and a lower amount of radiant heat). Just like it feel hotter in the sun than in the shade on a hot day. To continue an analogy, if the sun's directly overhead, a flat roof's going to be hotter than a peaked one (all other things being equal), because the same amount of radiant heat's spread across a smaller area.

   Mike BR - Wednesday, 10/19/11 20:33:53 EDT


I skipped over your offer when I was reading before I posted. Please point out what I've missed -- I'm always glad to learn. (I worked at the patent office for a while, and don't envy your perpetual motion assignment. Luckily I didn't have to deal with those folks myself.)

I was asked by a newbie at our guild forge if he could shape his file into a knife by hot rasping (filing) it. I didn't see why not. Might be worth a try for you.
   Mike BR - Wednesday, 10/19/11 21:24:30 EDT

Mike T : You can not heat treat high speed steel in a home shop and get the results that professional heat treaters can, period. This makes the use of them impractical.

On cold work aplications like punching steel sheet, M4 or any of the high speed steels don't hold an edge much better than a High Carbon/High chrome tool steel like D2 or D3, and You can do a reasonable heat treat on those in a home shop.
   - Dave Boyer - Wednesday, 10/19/11 21:27:02 EDT

Rudy : Bite the bullet and get on with the job. The old foot pumped wheel may look neat, but it won't remove much material. It is a poor abrasive and the surface speed is really low by comparison.

It is worth mentioning that the vermiculite MUST be ABSOLUTELY DRY to be a good insulator.
   - Dave Boyer - Wednesday, 10/19/11 21:32:26 EDT

Pot Racks AKA Dutch Crown :
Robert, I answered your question immediately after you posted it Sunday.
   - guru - Wednesday, 10/19/11 22:10:15 EDT

Grinding with old natural abrasives :
Natural grindstone materials are VERY inefficient and were never used for stock removal blade making (a modern process using powered high efficiency abrasives). Natural grindstones, especially manually powered stones, are good for light sharpening and finishing only. Heavy grinding operations using them used very large diameter wheels generally powered by some means (wind, water). But they were still a finishing process.
   - guru - Wednesday, 10/19/11 22:29:09 EDT

forging stainless steel : What type of stainless steel is most suitable for hot forging?
   chris gavin - Thursday, 10/20/11 08:20:29 EDT

Stainless Steel : That depends to a large degree on your intended use of the final product, Chris. If you want to make hardware, art items and such, then 304L is nice for that and about5 the easiest to forge. If you need high corrosion resistance then 316L is a better choice. If you want to make cutlery, then you need to be using the 400-series stainless steels, which are harder to forge and require complex heat treatment to achieve optimal properties for cutting tools.

No one metal is best for everything.
   Rich - Thursday, 10/20/11 08:30:57 EDT

Stainless Steel : Also note that while forging stainless is only a little more difficult than mild steel provided you keep it very hot, everything else about stainless is equally more difficult as the price. Stainless is hard on cutting tools (saw blades, drill bits and files) and more difficult to finish. These add up to much higher labor and overhead (3 to 4 x).

If you normally do a first class job finishing your work (4 step paint job) then much of the cost difference balances out, but not all.
   - guru - Thursday, 10/20/11 09:58:41 EDT

That foot driven natural sandstone wheel was only used to *SHARPEN* the edge of tools. Shaping was done by hammer and file in small shops.

In places like Sheffield that specialized in Cutlery the natural stones started out up to a dozen feet in diameter and so provided a high SFM at low RPMs. As they wore down they would go from primary grinding to detail grinding to finish grinding just like a modern knifemaker migh start with 36 grit and go to 80 grit then 100, 200, 300, etc.

Down below one of the former Anvil works in Columbus OH you can still see a dozen or so of the old standstone wheels used to dress the faces of anvils---when they got down to about 4' in diameter they were removed and rolled down into the river as too small to mess with.

People get a quite odd view of historical technologies and I seem to be always telling folks who "want to do it the old way" that the first metalworking powerhammer I have heard of was in the 900's and the most common tool used in historic smithing that people tend not to use is *MORE* *PEOPLE* even in the shops in photographic times you tend to see a half dozen workers.
   Thomas P - Thursday, 10/20/11 12:58:42 EDT

Anvils : There are not that many forged anvils to choose from. The only one I know of is the Peddinghaus. The rest seem to be cast tool steel. So how would you rate the following anvils ?

1. Kohlswa - cast
2. Rat hole - cast
3. Peddinghaus - forged
4. Refflinghaus - cast
5. Old World Bulgar/Italian - cast
6. Old World Austrian Workhorse - cast

   Greg - Thursday, 10/20/11 16:31:53 EDT

#1 is Nimba! IMHO
   - GRANT - Thursday, 10/20/11 17:37:26 EDT

OBTW: I understand TFS anvils are heat-treated alloy ductile iron.
   GRANT - Thursday, 10/20/11 17:48:18 EDT

Anvils : Personally, I'd rate the (cast steel) Nimba #1 as a forging tool
Rat Hole #2, because it is highly stylish.
The rest are also-rans. (grin)
   Rich - Thursday, 10/20/11 18:39:59 EDT

4 step paint job? : Explain please, GURU.
   - danny arnold - Thursday, 10/20/11 19:21:28 EDT

anvils : Fontanini gave me a good deal on the 250# "Rathole" a few years ago. It's a good anvil. I have it held steady in a box of sand with straps, allthread, and nuts. Cast in the USA.
   Frank Turley - Thursday, 10/20/11 21:24:36 EDT

Sandblast or acid bash clean and etch, Zinc cold galvanize, Neutral primer (such as Dupont red oxide or grey sanding primers), the a top coat of whatever finish you like (Lacquer, enamel, epoxy. . .).

Optionally you can hot dip galvanize (many government contacts require it), followed by an etching primer for zinc and top coat as above.
   - guru - Thursday, 10/20/11 21:43:22 EDT

Anvils : In regard to the also rans, because of style or material they are made out of ? I'm interested in how you rate them as to material not so much style of anvil.
   Greg - Thursday, 10/20/11 21:48:20 EDT

Kohlswa is no longer imported into the US from what I understand. So its off your new anvils list.

From a materials and manufacturing stand point Peddinghaus should always be #1. However, they went through a period of producing rough anvils and are still not finished they way they should be. DO NOT mistake the cast "Peddinghaus" style for the real thing.

Nimba and Rat-Hole are right behind Peddinghaus due to quality materials and manufacturing. I have not seen a new Nimba since Russell Jacqua died but when he was finishing them they were the best.

All the Eastern European anvils vary from one batch to the next due to shopping out their manufacturing to whatever foundry is desperate for work. All are made from low quality patterns. When they were selling for $2.20 US/pound they were a good deal but prices have gone up and the quality is inconsistent. They are a product that WHO you purchase them from, and the terms of THEIR warranty are important.

From what I have seen of them the pre WWII German Söding & Halbach anvils were probably the world's finest anvils ever made. They were forged, machined and hand dressed. This starting with a superior no compromises design.
   - guru - Thursday, 10/20/11 22:15:47 EDT

Anvils : OK, I appreciate the advice given. I think I'll go with a No. 9 165# Peddinghaus. Should serve me very well. The rat-hole is really nice but it's too expensive. Tempting though but it's a little heavier than what I was looking for both as to price and weight.
   Greg - Thursday, 10/20/11 22:57:55 EDT

Energy : Mike BR,

Ooohhh, a chance to preach!

Well, this is a hard science type group and there were no absolute mistakes, but a few small refinements and one big refinement should do it.

Dave Boyer was essentially correct with some minor changes: We paid 1.5 cents for a kWh of energy (same price we paid to get it from the utility next door - PG&E), we charged 8 cents per kWh. The difference was "overhead" (see major item below for details).

Dust on solar panels needs to be rinsed off in most areas, BUT not all. (one of the "little complications" that justify engineer's high salaries)

Dave was wrong to use the term "power". Solar panels do not (for practical purposes, produce power, most alternatives produce energy, but you cannot rely on them for power - see major item below).

In Berkeley, the sound bite was "the sun is free". Well, Yyesss, rain is also free, but the bucket to collect it and the pipe to get it where you need it aren't free.

Now, about my big opportunity to sound off:

Dave repeated one of the most common vocabulary mistakes of the energy industry. Despite common usage, POWER IS NOT ENERGY! To explain, energy utilities do not sell just energy, they sell a lot of products. Most of these are, and should be, transparent to the customer. LOLP, black start, reserve margin, the difference between a base load and intermediate and peaking plant, etc. make and break energy engineer's careers, but they mean almost nothing to the customer.

However, if you are going to talk about energy generation, and utilites, and alternative energy sources, there are TWO things you MUST understand. Energy companies sell energy AND capacity (that is the term used in the energy industry, for the rest of us it is usually power - which ain't energy). By analogy, in an automobile, the gasoline in the tank is your energy, the size of the engine is your power. Power is the rate of delivery of the energy. One of the biggest problems of the energy industry is not generating the energy, but getting the energy to the customer in sufficient quantity to "power" the devices he has running at the moment.

The problem with most (not all) alternatives, is even if the energy was free, you would still need to back them up w expensive (usually) load following plants to cover your peak load when the alternatives just weren't there.

Even w free energy, you are going to pay - a lot. Transmission, distribution, synchronization, voltage regulation, imaginary energy, reserve margin, i.e. "overhead" comes to more than the energy itself.

Things just plain ain't as simple as the Berkeley nut jobs (most of whom were nice, intelligent people) think. Closing your distribution system is great. Now you have reduced the chances of an outage (by a lot). However, now your engineers go nuts keeping everything synchronized. Oh, yes. Have a well trained line crew and good insurance w the closed sytem for they will occasionally blow themselves into low earth orbit. There ain't no free lunch.

I can go on for pages, but basically, most of the alternatives are "diffuse". Even if the energy is free, the collection, distribution, etc. isn't free. AND if it isn't there when you absolutely need it (3:00 PM, July 15, Los Angeles) you pay an arm and four legs to back it up with something else.

I love talking, feel free to ask.


   Rudy - Friday, 10/21/11 01:58:37 EDT

Energy costs : Oh yeah - those ancillary costs do get appreciable.

Here in the VI we pay a "base rate" of 11.8 cents per kilowatt hour for electricity. Sound good, right? The kicker is that we have additional charges for some ancillary costs like "service charge" (flat rate of $7.21), "line loss surcharge" of .002 per kWh, "pilot surcharge" (?) of .0006, and our infamous "Levelized Energy Adjustment Charge" of $0.31 per kWh (that covers the high cost of fuel for the turbines). So the final rate I pay for electricity is actually more like $0.46 per kWh - OUCH! Guess why I don't have an induction forge, incandescent lighting, electric stove, etc.

In an isolated place like the VI, with no grid, no hydro power, outdated equipment, etc, alternative energy sources become more viable. Payback on a photovoltaic system is only about 6 years here. It's the front-end cost that stops me, as I'm only renting. If I owned my property I'd go with PV, wind, oxen on a treadmill, gerbils in a wheel, or something to offset the cost of local electric power. Be a fool not to.
   Rich - Friday, 10/21/11 10:56:04 EDT

Alternative Power : People don't realize when they put in a solar or wind system just how hard it is to be 100% utility independent. The battery banks are huge and expensive as well as having a finite life. The system size must be large enough to take motor surges (about 5x the motor rating) and possibly multiple motors starting at the same time. This is a complex enough problem that house and shop wiring should be designed with a control and delay timer system to prevent multiple motor starts as it adds a LOT to the necessary system capacity.

However, frequency control and surges are much simpler to cope with using the new digital controller systems. They also automatically connect to the grid so you have the reliability of the utility company as well as lower cost of power. YES, having the utility there IS a necessary evil (and expense) unless you are prepared to do without power for significant periods. The down side is the digital controls are not cheap and if anything fails it is like much other digital equipment, you replace it rather than fixing it.

Leaning on the Grid: To avoid complicated synchronization and voltage regulation systems the small hydro people do what is known as "leaning on the grid". This assumes the incoming line is hot and that the power company capacity is so much larger than yours that you cannot affect it. Simple induction motors are used for generators with no excitement. The turbine is brought up to near synchronization speed and the power connected, then the turbine is sped up enough to push more electrons OUT than are coming in (reverse EMF). I know this system very well as I've had my hand on both the turbine throttle and the power switch simultaneously while standing on the turbine housing. . .

When rating generators for such a system the operating speed is about the same amount higher than synchronous speed (1800 RPM) as the full horsepower load speed is below synchronous. Example a 1725 PRM motor would run 1875 (reverse slip).

Leaning on the grid works on significantly sized systems including former utility hydro plants (hundreds of HP). The down side is they produce nothing if the general utility is off-line.

Way back in the 40's just before the tensions with the Soviet Union Buckminster Fuller of geodesic dome fame had an international electrical grid peaking plan. This was based on an Arctic electrical distribution system so that off peak power plants on one continent could supply power to another that was on-peak. There was a lot of interest in it until politics made it impossible.

Solar: As Rudy pointed out, there is no "free" energy of any type. Without the means to utilize it, control it, store it, you have nothing.

The new solar systems (due to digital controls and better storage) are much better than a decade ago and with passing of time will continue to get better. The biggest difference in the past few decades has been the reduced cost per installed KW. But there is still a LOT that can be done to improve efficiency of solar cells AND storage medium. In the summer peaking South a good efficient solar panel should also reduce solar gain to the house - two for one.
   - guru - Friday, 10/21/11 11:34:27 EDT

The only realistic solar for home heating is to build the home for solar heating in the first place. To retrofit is simply not cost effective.
Mine has paid off but probably took 20+ years. The real benefit of building a house for solar, is that since solar will not generate much energy, the house must be very well insulated and not need much energy.
   - ptree - Friday, 10/21/11 13:53:13 EDT

Energy : Rich, Guru,

I can obviously write a book, and this isn't an energy forum, but FYI:


It sounds like your utility is trying to "unbundle" their charges. Unfortunately this is a good AND bad thing. It's a good thing in that the customer sees exactly what he is paying for, and it is FAIR. It's a bad thing in that it's complicated beyond belief for the average user, the politicians can't howl about the dishonest utility, and the guy who was getting free ride now has to pay just like everyone else.

My personal opinion (opinion - not gospel) is that unbundling should be done to a limited degree. The customer should get a base charge (what it costs the utility just to be ready to serve an empty house if the owner comes home unexpectedly), energy charge, and time of use, and miscellaneous (which might be more than the others combined).

When they first started selling electricity, they knew about all this, but analog meters were just too complicated so they rolled everything into an energy charge to keep it simple.


you're right, there are special situations where things like solar are the smart way to go. I can't think of any other practical way to power a satellite or one of those weather stations a 3 day mule trip into the back country.

Getting off the grid is fiendishly difficult and usually forces you to become your own solar, battery, transformer maintenance expert. Again, an exception: Some years ago the utility in Oregon (Idaho?) set up a deal for people in the back country. You buy a solar system from them. If it breaks, get on the horn. A couple hours later a truck w some genuine experts shows up and fixes it. Of course you pay the utility for the service even thought technically you are not a utility customer.
   Rudy - Friday, 10/21/11 13:53:38 EDT

More Solar :
Cost of a 20KW system IF you engineer and install it yourself is about $10,000. Currently there is a $3,000 US tax credit and a $3,500 (over 5 years) North Carolina tax credit. That means the first year cost would be $6,300 (10,000 - $3,700). Average estimated production (4 hrs/day avg), 75% efficiency is about $1500/yr (based on various published values and further reduced by me). So the first year invested cost would be $4,800. Second year payback would be $2,200 with the NC credit (90% of our current electric bill). This would leave $2,600 for the third year minus another $2,200 so all that is left is $400 or so going into the forth year. For this and the next year of the NC tax credit we would have "free" or almost free power and the system paid for. Worse case is it would take the full 5 years to pay for itself.

After that there would be maintenance costs (a fried controller could cost $3000 to replace unless covered by homeowners insurance, - panels are supposed to have a 30 warranty but the company that sold them still has to exist. . . batteries supposedly a twenty year life.). The advantage drops from "free" power due to the tax credits to very low cost then about 30% to 50% of utility cost due to maintenance.

The problem for many is that my costs above are for a relatively "cheapo" DIY system. Costs supposedly can be reduced further if you build your own panels (a LOT of labor). The above assumes above average electrical skills as well as mechanical. A contractor installed system would probably cost double. Payback would be much longer and there would be no period of "free" energy.

There are other considerations as well. While our location is good and the house oriented nicely the roof slope is too low for optimum solar. It is also a "modular" home and the roof is not very stong. It is 7 years old (out of a 20 year shingle life). Putting a 30 year system on a a roof with half that life does not make sense. A better route would be a free standing system in front of the house. But this adds to the cost somewhat. Its not just the supporting frame but a long life foundation and site work.

The hard part, even though it would pay for itself in a relatively short time is coming up with that initial $10,000 - $11,000. . . or more. Things always cost more than you expect.
   - guru - Friday, 10/21/11 15:48:17 EDT

Solar : The local folks, for the most part, are completely bamboozled by the unbundled electric billing. They think they're getting surcharged, for some reason. They simply refuse to accept that it costs a potful of money to generate electricity with fuel oil and that someone has to pay for it - a legacy of the paternalism of the past centuries compounded by the current welfare state, I'm afraid.

Down here solar is the way to go, no question about it. With tax credits, both federal and local, the front cost is roughly halved and the payoff is great - over 325 sun days a year for six to eight useable hours per day. We only need the electricity for lighting and refrigeration, for the most part (at the house - shop is a whole other deal!), as stove is gas and water would be direct solar. No need to heat the house, ever. No real need for AC, unless maybe a small unit for the bedroom. Our solar influx is sufficient to make it a sure thing. As noted, the only thing stopping me is that I don't own the blasted place. When/if I do get around to building it will definitely be a solar home.
   Rich - Friday, 10/21/11 16:10:00 EDT

Nimba Anvils : When Russell was still alive, Jim Garrett was finishing his anvils. Now, Jim owns Nimba, and Jim Garrett is still finishing the anvils.
Hence, there has been no falloff in the quality of finish.

For some reason, up here in the Northwest, we are a hotbed of locally produced anvils.
Renato Muscovik of British Columbia did a run of amazing 450 lb or so euro pattern anvils, which are the size of aircraft carriers. Formidable, as the french would say. Only available used, and rarely, though.

Then, Kris Ketchum has been making the Blackjack anvil- again, in the 450-500lb range. These have a variety of innovative hardy holes, including hex shaped ones, as standard.

Both of these are cast tool steel anvils, like the Nimba. Both are rare, expensive, and really impressive. The guys I know who have used them love them.
   - Ries - Friday, 10/21/11 17:16:17 EDT

gas forge info : I am planning a rather large gas forge, a lot of heat will be exiting the forge in the stack gas, Would a STERLING engine turn a blower?
   - danny arnold - Friday, 10/21/11 21:23:22 EDT

Solar : The grid tied system My friend has was installed by a contractor. It is on it's own supports in the yard, not attached to the house or roof. They are in an agricultural area with not a lot of rain, dust is a problem. This 9 KW system cost 40K out of pocket after rebates & tax credits. It is sized pretty well for their power usage, as a grid tied system, but would need to be quite a lot larger if it was to be stand alone. It has been in operation about 2 years.
   - Dave Boyer - Friday, 10/21/11 22:12:03 EDT

Living off grid : I and many of My friends lived without grid power on Our sailboats. I have a better system than most, but in spite of having a wind generator, most of My energy came from burning diesel fuel in an engine.

For 120VAC I use an 1800 watt 12 VDC to 120 ACV inverter. The DC system was 6 golf cart batteries in a series/parallel arangment. This provided 645 amp hour capacity as measured by BCI standards for 20 hour discharge rate.

The majority of battery charging was done by a high capacity alternator driven by the propulsion engine. This was limited to 135 amps flowing into the battery bank, and 14.6 volts max. When acceptance amperage dropped sufficiently, this systen would drop to 13.4 volts to prevent overcharging with extended engine operation. This system would operate at any engine speed over 1,000 rpm.

My refrigerator compartment is suficiently large that I could get inside and shut the lid. I was about 185# the last time I did that. The freezer compartment is about 1/4 this size. These compartments use thermal storage plates, aluminum tanks filled with a glycol/water mixture with the evaporator coils inside. Glycol/water is not a true eutectic, but that is what this system uses. Solidus in the refrigerator plates is 25f and 0f for the freezer. The compressor for this system is driven by the engine and operates at 1,000 rpm or greater. The run cycle is 45 minutes (2) times per day with full heat load in the tropics in summer. Because all the evaporators are plumbed in series, frezing the refrigerator can happen with low outside temperature.

Hot tap water is heated by waste heat from the engine. The heater tank holds 6 gallons, but that is way more than enough, as You only dare use 1 gallon for a shower, and I had long hair & a big beard back then.

I later used a solar heated jerry jug with a gravity feed in the shower, as I could use poor quality local water that wasn't good enough to drink for showers when down island.

I used a Red Dot truck heater off the engine cooling system any time the engine was running during cold weather.

I have a 5K btu propane heater in the aft cabin that I used in cold weather so I could come out of the shower and not freeze dry.

Lighting is a mix of 12 volt flourecent and 12V filament, white LED were not available when I started cruising, and were way too expensive when they first became available.

Air circulating fans are 12 volt and draw .3 amp on low & .5 amp on high. I wore out many of them in a 12 year period.

I used electricity for most of My cooking before I converted to a propane stove. On the propane stove I used the top burners, but still did a lot in the combination microwave/toaster oven and electric cook pot/fryer.

This system uses 1/2 gallon of fuel per day, and that provides for about 2 KWH of electric usage per day. Significantly greater power usage requires greater engine time than the 45 minute (2) times/day refrigeration cycle. If the engine was not used for propulsion, I carried enough fuel to operate the systems for (4) months in the internal tanks.

One of My friends using (2) Air Marine wind generators and a solar pannel seldom has to run the engine for electrical generation in the winter in the Bahamas [the windy season]. He is using an electricly driven refrigeration system, but it is MUCH smaller than the system on My boat. He uses no electric cooking devices, and has gone to LED lights.

   - Dave Boyer - Friday, 10/21/11 23:01:46 EDT

Danny : You COULD use the waste heat from a forge to power a stirling engine to power a blower, but You would have the most expensive forge in the world.
   - Dave Boyer - Friday, 10/21/11 23:05:30 EDT

If you could create a good enough seal where you inserted the work (a *big* if), I think you could use something like a low pressure turbocharger to run the blower. Because the hot exhaust has a much greater volume, you should be able to take enough power out of it to force the intake air in. In effect, you'd be building a jet engine. Hopefully it wouldn't run away . . .

The other advantage is that building it would prove Dave wrong -- the stirling engine forge would then be the *second* most expensive in the world. (grin)
   Mike BR - Saturday, 10/22/11 08:21:41 EDT

My 2KW $10,000 solar system numbers :
Phillip from China pointed out I had a math error in the first year. . . So I've corrected the numbers. The payback is a bit longer and the true "free" electric period is a bit shorter.

The other thing I left out is that even if you are making all your own power if you stay connected to the grid as a backup or buffer most utilities have a minimum billing even if you use NO power and many of those additional local taxes and fees apply even when no power is used. My minimum no-power used bill in Virginia was about $20/month!

In our case the local utility (a "COOP") does not have to bank OR buy our excess. So there would never be a credit to cover the connection fees. AND I suspect that taxes and connection fees would be considered seperate from the minimum power fee so there would ALWAYS be a small monthly bill (OR more).

In our case the 2KW system would meet 90% of our power needs 3/4 of the year, a lot more than we need 2 months of the year, and be short by 50% in January. That assumes all the weather averages hold true (degree days, solar days. . .). So we would need that utility hook up. A system twice as large would cover all but the coldest months but we would still need supplemental heat in the winter. That larger system would take a decade to pay for itself. Still not bad if you can afford it and are planing to stay put.

The other reason for staying connected to the grid is that the above is for a small house with moderate loads. However, none compare to striking an arc with a buzz box. . . It would take a LOT of battery back up and a much bigger inverter than priced into the system.

   - guru - Saturday, 10/22/11 10:40:36 EDT

Sterling Engines, Forges :
NASA has experimented with sterling engines for use in space and the auto industry has looked at them and neither found them useful. NASA has lookied into them numerous times as technology changed and just never found them economical or fool proof enough. I think they are a curiosity still looking for a home.

On a natural gas forge you are going to assume being connected to an Earth anchored pipe so what worry about the minuscule amount of power to run the forge blower? And no matter what system you used to replace the blower you would need some sort of start-up system to get things going. A lot of trouble to replace a venturi type atmospheric burner. . .

   - guru - Saturday, 10/22/11 10:49:32 EDT

Shop size : A friend and I are trying to start up a shop for blacksmithing. As I am the only one to have a house and a bit of a yard, it is going to be at my place. The only problem I have is room. I have a 10ft by 10ft shed that is 10ft tall in the backyard and my one car garage. I would love to set up shop in the garage, but I don't think my wife would like that too much. So shed it is, but is that enough space. I have a 130lb anvil that was my grandfather and a leg vice that some one is letting me buy off him. The shed has a barn style door that swing out, and I plain on placing two windows to allow air flow. To start off I believe it's enough room. I am thinking of adding a lean to off of it to add room. But I am just not sure. What do you guy's think.

Thanks for any help
   Walter N. - Saturday, 10/22/11 17:43:27 EDT

Walter : I started out with about that much space and it quickly grew too small, but I am, admittedly, a tool junkie. If you're going to stick with hand forging, filing and finishing, 10x10 may be enough space for quite a while, especially if you keep as may things as portable as possible so you can shift things around to suit your work requirements. A lean-to on one or two sides would be a great addition and I'm sure you'll do it sooner than you think. Blacksmiths seem to have the same properties as a gas - they expand to fill whatever volume they're in. (grin)

You don't say where you're located, and that can make a big difference. I'm in the tropics and only need protection from rain and wind, but you may need heat, too. Winter can make an outside work area much less practical, depending on your stamina.

In the final analysis, we all work with the materials and space we have available, and adjust our work to suit, to some greater or lesser degree.
   Rich - Saturday, 10/22/11 18:14:22 EDT

Space : I live in central ohio, weather is always changing, so as my grandfather said" Hate the weather, stay around a bit. It will change here soon. Weather here right now is starting to get cold, we just had two days of straight rain. But too day was an nice day....
   Walter N. - Saturday, 10/22/11 18:19:21 EDT


I'll second what Rich said. But if the two of you are planning to work together, it will make the space that much tighter. You'll need to be very careful to keep enough space open that you aren't tripping over each other. On the other hand, you have a space big enough to set up an anvil, forge, and vise and keep them under cover. I think that's the key to getting started.
   Mike BR - Saturday, 10/22/11 18:21:47 EDT

Space : A 12 x 12 is an average small bedroom. . . A 15 x 15 is reasonable space for two to work in. I've had three people in a 15 x 15 and it was OK as long as everyone was working at their own work station (lathe, drill, saw). But that can be VERY VERY tight for blacksmithing. Height helps.

Is your shed 10 foot tall at the peak and lower at the sides? Try raising your arm with a hammer in your hand. Are you going to hit anything? When two people are working together you can share a forge but it is difficult with coal. The tendency is for one person to break up the "just right" fire with a second piece of steel. A gas forge is easier to share but not in a space less than 12 x 12 without a hood and power ventilation. . .

Step one is to determine what is allowed in your yard. Permanent buildings are often limited but temporary buildings are not. Go for as much space as you can afford. A 15 x 20 is good, 20 x 20 better. Put some strong framing in for when you want to unload that power hammer from your pickup truck. . .
   - guru - Saturday, 10/22/11 19:22:14 EDT

space : Guru: the shed is shaped like an barn, tall in the middle and shorter on the sides.
Where I live I can have up 100 sqf. with no perment. If I add on with a lean to with a sliding door I can make a lot more room. the side I want to do this too the ground starts to run down hill a little so this would give me some extra space too. Thankfully I learned how to do all this in agricultural science class and FFA.
I looked at getting a bigger shed but the price just was not in my range for what lowes wanted.
But maybe I can add 2 feet long ways and make it a 10x12, I will have to look into it.
   Walter N. - Saturday, 10/22/11 19:48:31 EDT

Space Issues : All of my forging equipment is in a 5 by 20 area along the north-west side of the shed in my backyard. Vice is mounted farthest from the front, but about 6-8 feet (2 steps) from the forge, the forge is against the wall, the anvil is about 3 feet from the end of the forge, with stock in select sizes inside the barn. With addition of a power hammer, I must now either build a shop, or rent one. (Yay, finding a shop close to home, in my price range)
   HH - Saturday, 10/22/11 23:28:44 EDT

Size of coal : What size should coal be ? I've read pea-sized, walnut sized, but what is the proper size ? Probably depends on the job at hand. I've been experimenting with some local steaming coal and it's not very good. Doesn't pack very well, and has too much ash. I have some good coal I want to try but I need to break it up.

   Greg - Sunday, 10/23/11 00:06:44 EDT

Blacksmith Coal : Greg, good blacksmith coal is top grade bituminous in the "nut" size (larger than stoker). Nut size is 3/4" to 1-1/4" lumps or thereabouts. There is probably a specific screen size for it. Smaller coal, stoker and pea, works OK but has a tendency to fall down the tuyeer of bottom blown forges. Pea and breeze (dust) are used in side blown forges.

Lump coal varies from golf ball up to softball sized lumps and is a pain to break up.
   - guru - Sunday, 10/23/11 03:35:56 EDT

Space : If you have an anvil and a vice you need a couple of hammers, a source of heat and you are away! First job is make a hardie. You have got what I started with and about as much space so let's hear what you have made in your next post.
   philip in china - Sunday, 10/23/11 04:36:22 EDT

Large lump coal : I get large lump smithing coal from a local feed & fuel supply, and I think it comes from King Mine near Durango, Colorado. I have a concrete pad and tamper to break up the quite large lumps. However, I have found that once I get a fire going with coke, the nut size and a few fines, I can surround the fire with the larger lumps. As the lumps get hot, they begin to coke and they fractionize. They become easily broken with the fire rake into smaller chunks, some golf ball sized and some nut sized. It turns out that this makes a decent fire as long as it is kept well above the hearth as a deep fire in a bottom blast. fire pot.
   Frank Turley - Sunday, 10/23/11 08:19:00 EDT

really good coal !! : To see what ideal blacksmith coal should be like get a fifty lb. box from Kayne & Sons. It is almost unbelievably HOT!
   - danny arnold - Sunday, 10/23/11 08:32:58 EDT

The easiest way to learn about coal is to start with GOOD coal (as mentioned above) as a reference. Then you can decide if locally available fuel is suitable or if you would rather pay for the better coal.
   - guru - Sunday, 10/23/11 12:05:12 EDT

Coal : OK, thanks. I'll try 3/4 to 1 1/4 for the good coal I have and see how it works.
   Greg - Sunday, 10/23/11 15:42:36 EDT

Shop Size and Sharing : I did most of the hot work in my first shop in a space about 6' X 6'; but you need work benches and tool chests and such for all of the cold work you will end up doing, too. If you share the shop, it's important as to whether the other person is and "assistant" or a "partner." Assistants wait (time wise) on you, and it's a more compact relationship. This also applies when you're teaching another person, or when both of you are working on the same project- one person takes the lead and the other follows.
Partners or coequals, however, may be working on a completely different project, and you each lend a hand to each other from time to time. This requires a higher form of cooperation (and patience). It also sometimes requires different fires for different tasks. In my new forge, in addition to being roomier, I have both the coal forge and the small gas forge, and the anvils arranged so that projects can be run in parallel. This works really well for both teaching and running parallel projects; you still need to coordinate, and you must be extra careful so that everybody knows what everybody else is doing. (...it's a little like a ballet at times, BUT WITH HOT, GLOWING IRON! ;-)

I'm lucky down in St. Mary's County; we're a largely rural area and they don't worry about structures of less than 300 sq. ft. However, you might want to check out just what would be involved for a larger structure; depending upon the local government the regulations for a "workshop" might not be too onerous.

I like the idea of the outside lean-to for storage of stock and supplies; both neat and handy.

It is a lovely, cool, and sunny day on the banks of the lower Potomac. I had to sit-out Hastings XXXXIII this weekend, the first battle reenactment I've missed in many years; not enough energy yet to charge about in armor. I did drop off our Viking ship's boat, the cooking gear, and my wargear for my friends to use, though.

Visit your National Parks; www.nps.gov

Go viking: www.longshipco.org
   Bruce Blackistone (Atli) - Sunday, 10/23/11 17:37:32 EDT

Bruce we don't need you bringing TOO much reality to reenacting the life of an old warrior!
   - guru - Sunday, 10/23/11 19:04:24 EDT

My first shop was open air. Drug the stuff out under the shade of a Persimmon tree:)
Then I built a leanto on the main building that was 9'x9'. Tight, but I used that for a couple of years, and taught my oldest in that shop. But junk expands to fill the space allotted, and I have just expanded my shop yet again.
   ptree - Sunday, 10/23/11 19:04:47 EDT

Small Shop and Attached Garages :
Attached garages are nice for some things but there are many things to think about before doing metalwork in one.

1) Fire smoke, fumes blowing into the house.
2) Airborne dust dirt grit.
3) Sharp metal chips (drill, die grinder, lathe, mill) tracked into the house.
4) Noise at night. . .
   - guru - Sunday, 10/23/11 19:12:45 EDT

Blacksmiths are like crustaceans, we grow to fit whatever shell we are currently occupying. My first shop was a 10x12 lean-to open on one side. Up here that means that the snow blew in to cover everything, even that shelf up high in the back. Now I have about 1000 sq. ft. and it's still too small.
   Judson Yaggy - Sunday, 10/23/11 21:12:52 EDT

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