Phillip from China writes:
A favourite complaint of mine is the junk that is on the internet telling you how to do things- by guys who obviously know nothing, or almost nothing, about the subject.
As a part of my training project for guys crippled by the earthquake I am going to do some very basic metalworking training.
So I thought project #1 could be making a welding bench - teach them measuring, cutting, prep for welding, making things square etc. etc.
Nice basic project.
So I looked on the internet to see if there were any plans - try to teach them to follow plans as well.
The first one I pulled up suggested using 1.6mm steel sheet and bracing it underneath with plywood!
Trouble is some people see such things and think it will work!
Imagine the fire risk!!
Frightening! I consider my 20mm plate to be barely adequate. . .
There are welding benches and there are welding benches. None are cheap.
There are four basic types of welding bench. Steel top, Brick top, Ventilated top, and heavy cast platten.
The basic bench has 1/2" to 1" (12 to 24 mm) plate supported by heavy angle.
I use 4" x 4" x 3/8" (100 x 100 x 10 mm) for legs, and 3 x 3 x 3/8" (75 x 75 x10mm) for framing.
On mine I bolted the 24mm top plate on with 1/2"-13 bolts installed from underneath then cut and ground flat on the top so they filled the holes but could be removed to facilitate moving the bench.
In the center of the 300 pound plate I taped a hole for a 3/4" eye bolt. It is stored underneath filling the hole and also cut off and ground flat.
Under the bench I used bar grating for a shelf about 1 foot of the ground.
The frame for this stiffens the bench.
Another bench used when lots of torch work is done but also arc welding is a fire or refractory brick surfaced bench.
These are supported on heavy bar grating so air can cool the brick and moisture is not trapped.
My big welding bench has a 3 x 3 foot by 1" thick steel plate on one end and 3 x 3 foot 2-1/2" thick refractory brick surface on the other with heavy frame as described above.
The fire brick end weighs about the same as the end with steel plate.
Toatl weights 1300 pounds (590 Kg).
It has a thick brass plate bolted to the frame with a heavy copper lead going to the bench surface and a short cable with a ground clamp. The clamp from the welder attaches to the brass plate.
Yet another type is the down draft ventilated spatter catching bench.
This has a 1" x 1" spacing bar grating work surface and a funneling down sheet metal duct underneath and "back splach" on the back.
There is a clean out door on one end (and for retrieving lost tools and pieces).
An exhaust fan sucks smoke DOWN and out of the shop through one end or the back.
In use a small steel plate is set on the bar grating to support small parts and create a flat work surface.
This is a very HEALTHY bench.
It also catches many pounds of sputter balls that usually end up on the floor.
In a shop with a semi smooth concrete floor sputter balls, especially from MIG welding can be like walking on ice.
So, smoke goes out, and a high percentage of sputter balls are also trapped.
Bar grating can support many hundreds of pounds so it is not a flimsy bench - just ventilated.
These are very good when most of the welding is bench work and for production ESPECIALLY in a small space.
Working with toxics? THIS is the bench.
Bar grate surface benches with catch trays are also used for flame cutting benches but that is another subject.
AND the bench of benches for the industrial welding and blacksmith shop is the heavy cast iron weld platten.
Also called a platen table or Acorn plate.
My friend Josh introduced me to these wonders. He had a 5 foot square by 8" thick platen at the time. Weighed more than two tons. Today he has a 6 foot by 12 foot and a 5 by 5. The 5 x 5 is used for a general work bench and has a vise mounted on one corner. The big double bench is reserved for assembly of gates and fencing.
Platens are cast iron with sides about four feet square and larger, 8" (200mm) tall and a middle 2" (50mm) thick.
A 4 x 4 foot platen usually weighs about a ton but "solid" platens that are equal thickness all across are much heavier.
There are large square holes in the top located on a grid about 8" (200mm) apart. Some benches have ribs between some of the holes to make the bench stronger.
The holes in the bench are used with L shaped bench dogs about 1 x 1 foot made of 1-1/4" (30mm) round bar.
Drop one of these in a hole and give it a tap with a hammer and it will hold tight enough to lift the bench.
They look like a wood working hold down except much heavier.
A couple raps behind the curve and they pop out.
While these are the most common clamps the Acorn company makes screw clamps, pivoting dogs and burning pyramids as accessory tools.
Like many other work holding surfaces in the shop the furniture is what makes it useful.
Double Bend (Belly) Picket Bending on a weld platen from Benders 3
like all work benches need to be built solid and be well anchored.
Due to their weight these are a great place to attach a vise.
However, a vise can be an obstruction to using the bench for building things as large as or larger than the bench.
If possible mount the vise on a leg so that the jaws are no higher than the top of the bench.
If mounted this way on a leg it can still be used for sawing off the side of the bench but not interfere with work on the bench top.
Vises mounted on weld platens should be attached with pegs and wedges so they are easy to install and remove.
As different as they are all these benches have their place.
More photos and sketches coming. . .
The trick is photographing my big bench. It is loaded down with about 1,000 pounds of "stuff" on the shelf and always has something on top!