Thin sheet metal welding

[itsme]

Hi there,

I'm looking for some advice on welding thin sheet metal (possibly 0.5mm or less). It would either be mild steel or stainless steel.

What types of welding are good for this (in a small home workshop)? Would MIG welding work for this? How about oxy acetylene?

Any thoguhts?

Thanks
Warren

[gotis]

Originally Posted by itsme Hi there, I'm looking for some advice on welding thin sheet metal (possibly 0.5mm or less). It would either be mild steel or stainless steel. What types of welding are good for this (in a small home workshop)? Would MIG welding work for this? How about oxy acetylene? Any thoguhts? Thanks Warren

I once saw a guy cutting Cokecans in two and welded them back together,
he used a acetylene/oxygen "Dillon weld"

http://www.cut-like-plasma.com/dillon_torch.htm

[pen25]

well theres a diffeence in welding stainless and mild steel. i would oxy/acl weld the mild steel with light filler rod. for stainless i would use a tig. but if you have a tig id weld them both with a tig.

[NC Cams]

High freq tig give pin point heat and fusion control.

Gas weld has large heat zone and resultant higher warpage potential. Mig (wire feed) is a bit on the crude side for light sheet metal welding. Spot welding is OK, but be prepared to do LOTS of short spots to weld 0.020" thick sheet metal.

I too saw a guy weld a pop can and real thin sheet metal with tig. IF you had small enough wire, you could probably weld lite sheet metal with mig but with care for sure to preven warpage.

[Mcgyver]

as alternative, why not silver solder it? sounds like it might be a heck of a lot easier - this crappy welder for one would be worried about blowing through .5mm stock, SS is very strong. since you say stainless, if its food make sure you use cadmium free stuff. as suggested, spot welds if design permits would be the easiest

[2muchstuff]

When welding thin mild steel with oxy/acetylene use a #1 tip with about 1lb of pressure. Tack both ends and make tack welds about every 3" or so. Go back and make stitch welds about 1" long skiping every other spot till fully welded. This will keep things from warping. Take your time and only use enough heat to get the job done. I have gone as far as adapting syringe needles to welding tips to get a smaller flame to weld very thin metal and welding under a magnifying glass.

[N4NV]

I like TIG welding the best. I have welded up aluminum cubes 3"x3"x3"out of .032" sheet and copper cubes 2"x2"x2" out of .024". Steel and stainless steel is even easier.

Vince

[widgitmaster]

I have never been a welder, but I have worked around them for 15 years, making special fixtures for welding and holding parts!

One trick for thin stuff is to use a block of carbon as a backup such as a corner, it keeps the tig tip from blowing a hole in the thin material, and it does not melt!

Eric

[itsme]

Hi there,

Thanks for all the replies.

It seems like oxy acetylene would be the way forward, as I don't see myself investing large sums of money in TIG.

I'm thinking about making a pulsejet, so silver solder is probably out of the question. These engines glow red/orange when running and after some brief reading, it seems like the temperature is very close to the melting temperature of silver solder and I'd rather not have bits of molten solder (and then large steel tubes...) being flung out the tailpipe.

Thanks again
Warren

[Geof]

If you are using stainless, which is the best choice for a pulse jet, you will not be able to weld it easily with oxy-acetylene. Bronze welding could work because it is well into red heat. You could also do a bit of research on Stellite. This is a hard surfacing alloy which, if my memory serves me correctly, can be applied using oxy-acetylene at around the same temperature as bronze welding but once it has been melted and resolidified the softening temperature to re-melt is higher than the first time.

[weldman]

Originally Posted by gotis I once saw a guy cutting Cokecans in two and welded them back together, he used a acetylene/oxygen "Dillon weld" http://www.cut-like-plasma.com/dillon_torch.htm

those cans are varnish covered alu. ...unless you have a good inverter TIG welder and years of training it's going to me almost impossable to do welding on metal that thin.

as for the .5mm mild steel..get a inverter tig....not a bad one from HF or home depot and put a copper block behind the weld area...it makes it much easier

my buddy just picked up a symcrowave 200 from miller....awesome machine...only draws 30A 220V single phase

the transformer units were going to draw about 60 amps...and his shop is wired with a 50A sub panel...ontop of that, the main panel is only 100A so if he wanted to upgrade the sub, he would have to upgrade his main....gets the prices up there

[weldman]

Originally Posted by gotis ... he used a acetylene/oxygen "Dillon weld" http://www.cut-like-plasma.com/dillon_torch.htm

now that is the neatest product i have seen in a while...nothing like my big O/A torch setup...ill have to get a price on it.