tig welding stainless

Date 07-20-2011 02:43

The argon gas will be fine. If You are good at scratch start steel You should have no problems with common 18-8 stainless.

Duplex stainless is another matter, and I have no experience with it.

By 52lincoln (***)

Date 07-20-2011 02:50

thanks i kinda figured it was like welding steel.been using 308 rods on his other equipment but, this is a deep fryer pot and its pretty thin guage.gonna kinda have to put a patch on it of some sort. really just starting to get the hang of this scratch start tig.again thanks

By DaveBoyer (*****)

Date 07-20-2011 04:31

I am not good at all with scratch start, because I have mostly used machines with HF start and a foot pedal, really spoils You.

I am not a TIG wizard period, due to not doing it often enough to get real good or stay that way. With HF and a foot pedal I can get by.

By 2006strat (***)

Date 07-20-2011 10:52

Just keep an eye on your heat zone when welding stainless. It gets heated faster the than normal. I like to use a smaller filler rod then I think I need. I need 1/8th I"ll get 3/32. It works better for me. Your argon dosent have to be blasting out of the tig head eather just enough that you feel it. Main thing just don't get irratated at it. It only makes it worse.

By qcrobert (***)

Date 07-20-2011 15:06

52lincoln,

Take 2006strat's advice on keeping your heat down. Austinitic stainless steel conducts heat at half the rate of mild steel, but it has a much higher rate of thermal expansion when welded. Carbide precipitation occurs between 800 and 1400 deg F so you should keep your heat well below 800F by making sure your travel speed is not too slow. You want your finished weld to be a straw color, not purple or blue and never black. I like to use a gas lens in that is provides better coverage and can use less gas pressure.

Just make sure you don't stay too long in one area and make your patch fit tightly with no gap and you should do fine.

I walked out to the shop and here is a project currently being fabricated.

Have fun,
QCRobert

Attachment: GTAWwithfill1.jpg (120k)

Attachment: GTAWwithfill2.jpg (162k)

Attachment: GTAWwithoutfill.jpg (520k)

Attachment: GTAWfinish.jpg (305k)

By 52lincoln (***)

Date 07-20-2011 20:51

again thanks guys.my brother has a miller bobcat if i cant get this heat down enough(my welder just sparks in 1st gear).would assume it is done the same way.not really familiar with the bobcat.,and he knows nothing about tiog

By qcrobert (***)

Date 07-20-2011 13:12

With very thin gauge steel you will need to make sure the patch is tightly held against the metal with no gap or as they say, "zero gap between the faying surfaces." A little practice and you'll have the scratch start technique down before ya know it. GTAW is my favorite welding process.

Here's belt buckle I made back in '78 in Texas with "misuse of (B&R) company materials." :evil:

Attachment: beltbuckle001.jpg (52k)

Attachment: beltbuckle002.jpg - back (51k)

By weldwade (***)

Date 07-20-2011 13:19

Good looking buckle Robert! I think the Statute of Limitations has expired on that investigation into where all that TIG rod disappeared to, you’re in the clear.

By 52lincoln (***)

Date 07-20-2011 14:38

thanks guys for the responses.got some thin stuff to practice on for a bit

By Cumminsguy71 (*****)

Date 07-20-2011 14:44

I did a water tank on an industrial dish washer around Christmas time, thin wall stainless with a crack where 3 welds met. Think I set my 200 on 90-min(1st gear?) and set the fine tune around 40-50 if I remember right, slept since then so not for sure. Used a 3/32 tungsten and 3/32 filler. Worked out good until the water pressure on the inside of the tank blew out a larger whole then sprayed me with water. My dumb mistake for believing the guy who said, "We'll have the tank drained for you when you come out in the morning" This was two days before Christmas, big rush job for a large store chain. Drained the tank myself, asked the guy about it and he says, "Ohhhh, yeah, forgot about that." Repaired the repair and still made it back to the house in about an hour and charged my minimum for it.

It's not difficult with the scratch start, same as carbon steel, scratch off the filler, set my argon about the same, 20-25. I like starting a bit low on the stainless til I know what I'm dealing with as far as heat input etc, rather stop and turn up machine then have it start to sugar or discolor badly. That's just me though and I'm no stainless guru either, just things that have worked for me.

By Superflux (****)

Date 07-20-2011 14:54

.035 or .045 MIG wire makes nice filler for the thin stuff. I also get some of the Insulators wire when I can. It is 304, which is hard to find at your LWS, since all they ever have is 308. The insulator's wire is often a better "color match" on 304 kitchen parts.

By paul prill (*)

Date 07-20-2011 19:03

The 304 insulators wire also works really well when making belt buckles!

By 52lincoln (***)

Date 07-20-2011 20:44

gonna have to try 2nd gear.for some reason my 1st gear doesnt work.thanks for the input

By Blaster (***)

Date 07-21-2011 13:47

If you purge the inside of the pot with argon before welding your results should be much nicer. If a purge were not possible a piece of copper tight up against the back of the area will go a long ways toward preventing burn through, scaling, "sugaring", etc.

By 52lincoln (***)

Date 07-22-2011 06:10

man there aint no way to purge it but,thanks for the tip.i'll post up some pics

By Superflux (****)

Date 07-23-2011 06:57

Solar Flux the outside, then weld the inside first to reduce scale and sugar on the cooking surface. Unless you can build a big enough box. I've often thought a Bead Blasting cabinet with the space man gloves would make for a nice purge box...?