what is the best surface to weld on? surely if you weld on a wooden worktop etc there is a risk of fire? what about jigs etc for chassis welding, what are they made of?

I tend to find a thick steel plate is perfect, it does not warp/ distort and u can use magnetic welding clamps on it, this is great for small parts but when its comes to chaissis building a steel jig would be best but its a case of time, effort, money and space espeshaly if you are only using it once. So the 18mm ply building board with 4x2 braces are the way forward there IMO put some holes in it so you can put clamps threw and some blocks around the rails to prevent them from moving

Hope this helps
Tilly

Welders benches tend to have a metal top that the earth strap to the welder is conected to.
That way you can just lay your work piece on and weld away

[Edited on 7/6/09 by snapper]

I have a 5mm steel plate on top of a paving slab, on top of a wooden bench. My plate has a tab welded on at the back for the earth clamp to live on.

Don't weld things sat straight on a paving slab though, the concrete spits little flecks off when it gets too hot.

ply wood and a bucket of water

I weld on top of a sheet of MDF. And I just blow out the little fires that inevitably start when it gets too hot!!!! Perhaps not the best option long term as MDF contains lots of nasties which I'm probably breathing in....

we have a thick steel table about 25mm thick,it also depends on what your welding ally holds heat,its a right pain,if i was you use a paving slab like someone says up there,also a little tip you can use a scaring pad to go over where you have already cleaned to weld,this just helps you to get a nice clean weld,mostly if your welding ally do this,but it wont hert

At work I have an 8`x4` 10mm steel topped work bench , with a matrix of 10mm holes all over it to hold steel pegs for lining up stuff .
At home...........I mostly use the garage floor

i made a alloy desk, top is mdf and then covered this with 3mm alloy sheet. seems to work great for alloy but marks when mig welding steel.

At work they have these great tables about 1200mm square and about 20mm thick made from alloy but they tilt making it eassier to get the part in the right place.

I often use a piece of plywood. I've scorched it but never started a fire. It isn't that easy to set wood alight.

John

steel tables sound good since they will not catch fire and be very flat but surely the steel acts as a huge heatsink if yoo are welding close to it?

hence wood would be good.

I personally use bacon, once I'v finished welding, it is nice 'n'; crispy just right for a butty!

Metal topped bench is best and a good heat sink...