Welding stainless steel

[notfarnow]

I bought a Lincoln 140C (110V) MIG welder last year. I have been a welding fool since then... I just love the thing and have had some really fun and challenging projects, like welding up a 115 liter veggie tank for my Mercedes.

Anyway, my big project over the next month or so is doing some re-rigging and rearranging on my 35 yr old Chrysler 22' sailboat. Part of that involves rearranging the stanchions at the stern, and incorporating a traveler into them, as well as a mount for my bbq and swimming ladder.

I have some 1" 316 SS tubing, and I'm confident I'll be able to make the gradual bends I need. What I'm not so sure about is the welding. I'm guessing I'll have to get a different wire, but what about shielding gas (I have 75/25 CO/argon)?

And what about technique? Is there anything particularly difficult about welding SS? If it's really specialized, I'd like to at least bend everything, line it all up, then tack it together to bring to a pro for final welding. If I just wanted to tack it together, could I use my regular wire & 75/25 gas?

[asphaltgambler]

I may be wrong here, but I believe that SS must TIG welded so as to have more control over the heat and rod feed. MIG may work but a TIG is what you need.

[TerryH]

I believe you want to use ss wire to weld ss and the argon ratio should be the higher number 75/25.

Actual welding isn't much different, but I haven't welded in 20 years, so I won't argue other's opinions....

[notfarnow]

Originally Posted by asphaltgambler

I may be wrong here, but I believe that SS must TIG welded so as to have more control over the heat and rod feed. MIG may work but a TIG is what you need.

Thanks! To distill your message, do you mean "MIG isn't as good as TIG" or do you mean "MIG won't work" ? I know TIG is ideal and makes beautiful looking welds, but I don't have a TIG and am just wondering if I can use my MIG. I don't mind if I have to grind & pretty up, as long as I have penetration & strength.

[lendaddy]

MIG will work fine on stainless. You can even use standard wire (obviously not corrosion proof) but get yourself a small spool of stainless wire and you're golden.

TIG is certainly superior, but it(almost) always is, so what's the application require?

Oh, and C25 gas is fine though again, not optimum. Again, it depends on the application requirements.

[notfarnow]

Originally Posted by lendaddy

MIG will work fine on stainless. You can even use standard wire (obviously not corrosion proof) but get yourself a small spool of stainless wire and you're golden.

TIG is certainly superior, but it(almost) always is, so what's the application require?

Oh, and C25 gas is fine though again, not optimum. Again, it depends on the application requirements.

Thanks! So I can even use my 75/25?? That's great news. I don't mind if I have to clean up a bit after, as long as it's strong.

Are there any differences in technique for welding SS?

[lendaddy]

Originally Posted by notfarnow

Thanks! So I can even use my 75/25?? That's great news. I don't mind if I have toi clean up a bit after, as long as it's strong.

Are there any differences in technique for welding SS?

Not really, I think it welds a little smoother but that's probably because it's usually kept cleaner Speeds/feeds are basically the same.

I say all of this from a manufacturing background, not an artist/specialist back ground. So if you want to know what's "best" look elsewhere, I'm telling you what works just fine.

[rick-l]

Have you looked around here?

http://www.hobartwelders.com/weldtalk/

or

http://www.millerwelds.com/resources/communities/mboard/index.php

[notfarnow]

Originally Posted by lendaddy

Not really, I think it welds a little smoother but that's probably because it's usually kept cleaner Speeds/feeds are basically the same.

I say all of this from a manufacturing background, not an artist/specialist back ground. So if you want to know what's "best" look elsewhere, I'm telling you what works just fine.

I'm definitely looking for "what works just fine"... so this is exactly what I was looking for, thanks!

Originally Posted by rick-l

Have you looked around here?

http://www.hobartwelders.com/weldtalk/

or

http://www.millerwelds.com/resources/communities/mboard/index.php

Thanks I'll check that out!

[Rot 911]

I've used the same 75/25 gas for stainless as I do for regular steel welding. Works ok. My welds looks just about as crappy with stainless as they do with regular steel. Nothing a grinder can't make look pretty.

[notfarnow]

Originally Posted by Kurt V

I've used the same 75/25 gas for stainless as I do for regular steel welding. Works ok. My welds looks just about as crappy with stainless as they do with regular steel. Nothing a grinder can't make look pretty.

Ha! My welds have gone from booger, to peanut butter, to knotted rope, and now they are just starting to look OK.... now and then. The big learning curve was making my tank... you can't have leaks! Took a lot of practice, but I learned more on that project than any other.

[asphaltgambler]

Ther ya go!