lap joint 3mm on .8mm

[BrokenBiker]

what technique is best for a lap joint with 3mm plate being welded onto .8-1mm steel?

is it best to run cold enough for the thinner metal, or run hot enough for the thicker metal and stitch weld?

 

[Shedendman]

i've used the method thats in the tats
http://www.mig-welding.co.uk/welding-tips.htm
found that very useful

 

[BrokenBiker]

cheers. I think I have some scrap from a fiesta wing in the shed so will try sticking some thicker stuff to that

 

[F.J.]

I find that setting the welder more for the thicker metal and running a bead close enough to the thinner metal that the puddle flows and melts into the thinner. However the thinner metal needs to be in constant contact (no ripples) otherwise it will blow away

 

[Jim Davey]

Use some clamps to press a strip of copper flat bar against the back of the thin metal. This will draw heat away from the thin metal and won't stick to it after. It will help to prevent the thin material from buckling and pulling away from the thicker section too.
Chunks of copper are dead handy things to have around if you regularly work on thin material.

 

[Lawnmowerboy]

A simple lap weld is easy. We weld 1mm perf mesh to 3mm mild for some cc to recorder boxes we do on a regular Contract. Just run at the power for 3mm and wash it slightly over to the thin stuff and the heat from the molten pool will melt it in ok. I'll try and find a picture as I wrote it up for one of my college jobs

 

[gaz1]

i hope these help

jim davey reference to copper flat bar is there

 

[sapperb]

Really Good videos..I very seldom weld anything under 1/8th" or .120mm

 

[BrokenBiker]

Really Good videos..I very seldom weld anything under 1/8th" or .120mm

are you sure you meant to write .120mm? that's awfully thin

 

[Lawnmowerboy]

I think he meant 120 thou. Which is about an 1/8" or 3mm

 

[Jan]

I wish that this kind of information/help had been available when I started stick welding. I might have been fairly decent at it by now!

 

[Lawnmowerboy]

This was for mig welding mate. No chance on 0.8 with MMA!

 

[BrokenBiker]

mma will blow through as soon as you strike an arc.