Joining Stainless Steel

[eslighton]

Hi. I need advice on joining Stainless Steel.

I am a complete novice with welding and brazing although I have a lot of soldering experience. My current project involves joining 316 stainless sheet (3mm thick) and I am stuck.

Brazing with silver solder using a MAPP torch gives a strong joint, but leaves the steel thoroughly blackened and probably open to corrosion. Soaking the blackened joint in vinegar made little difference. I had the sheet pieces cut to order (probably laser cutting) and brush finished and in the final assembly there are hard to reach spots, so I am hoping to find a way to join them that does not require massive refinishing. The finished product does not need extrordinary strength or heat resistance, but will be outside, unpainted & open to corrosion.

Tin soldering is probably not strong enough, but I might try it as last resort & would need a stainless steel flux that works at low temperatures.

I see beautiful clean welds in industrial stainless construction items so it must be possible, but is there a way to do this without exotic tools and skills?

 

[Joe_E]

My friend, who welds for a living and specializes in stainless, TIG welds it.

 

[Pin_Head]

Use Solar flux to prevent discoloration/sugaring. Or TIG weld it and backflush the inside of the weld or use flux.

 

[PAToyota]

To maintain the corrosion resistance, you pretty much need to weld it with a similar filler. TIG would be my choice.

 

[e9999]

I asked a similar question not too long ago here.
Some replies discussing it, fluxes, gas etc.

 

[RDC76]

As stated above by a couple others, Tig is the best process for that job with SS filler rod.

Rich

 

[brian]

tig, stick, mig, dual shield, take your pick.
for that gauge material, mig would be easiest to use. you will find that 316 filler, in any flavor will be rather spendy.