TIG welding stainless

[fusername]

Just kinda a gripe thread, but if anyone has any pointers I'd be all ears. I warped the hell out of my plate (bad jigging PLUS over heating it) welding that I was doing, and don't wanna post pics it came out that bad.... trying to stick a vertical piece of 1 inch tube onto the middle of 1/8 plate....

Anyways that is done, but now I have 400 joints to do of tube to tube with some square 1x1x.095 tubing, 304 tubing, and I am suddenly looking forward to it a lot less. New to the TIG, first time doing SS, and the pedal is acting up a little. I have fixed the pedal best I can, but I am leaning towards using fixed current and not having pedal control. Might make my own taper out circuit for when I turn it off, but only if they don't make a new pedal still, which I am 80% sure is the case.

[fusername]

so far it seems that the SS does not "wet" as well as mild steel, I need to use molten filler to get the two sides to flow together when starting up, where as w/ mild steel I had better luck getting a puddle started and then being able to add filler as I went. Also I have a hard time having a reasonably sized puddle, seems like either i only have it molten directly under the arc on a tiny point, or suddenly blow away the wall of the tube. Not sure if that is the SS or the pedal, since when I did most of the mild steel last time I just turned off pedal control and dialed in the heat.

[ProctorSilex]

I am interested in learning to do the same, so I can't help you
What kind of gas are you using?
What kind of TIG machine?
I MIG welded stainless once. It was a mess, but that was for a lot of other reasons than the stainless itself.

[Fiatdude]

First thing to remember is that stainless take about half the heat that mild or moly does -- I usually turn it way down and never use a foot pedal - -- kind of treat it like gas welding -- so turn your machine way down and then sneak back up on it -- it is easy to put to much heat into it -- so take your time -- TAKE YOUR TIME lol

[Piledriver]

SS can be very difficult if:
Poor fit: Filling gaps in SS is more of a PITA than otherwise. It conducts heat poorly, sort of the opposite problems of welding aluminum. Welding 2 machined surfaces with a perfect fit is the easiest thing in the world, if....

...You Clean it. Clean. I don't CARE if it LOOKS clean and "should" be clean because it's SS, it has an oxide layer on it (esp in the HAZ) Solvent to clean to touch then SS wire brush. (and don't use the aluminum one)

There are SS rods made if you HAVE to maintain corrosion resistance and other "SS" rods for APPEARANCE and welding to mild steel etc... If it structural or for appearance, there is probably a better rod with a touch more silicon or such in it to flow better.(check with your LWS, that's their job to help)

[tjenus]

we do a lot of pipe, if you can we tent flow a little extra gas on the inside of the pipe, make a big diff on stainless, also prep is key, the 3M combi wheels seem to be my favorite, clean with a good finish, NO HYDROCARBONS. watch what you clean your parts with, most cleaners do more harm than good. anyway just my 2 cents, thanks Tjenus

[Prtexx]

Stainless is easy to weld the key is to do your prep work. Make sure it's clean dry and remove any burrs to get 100% penetration you WILL need back up gas or flux to avoid oxidation. I have always used argon for my back up and make sure your tungsten is sharp and doesn't stick out too far. For a good looking weld watch your speed keep your heat down and use the correct welding rod. Gaps are easy to fill unless they are huge. I find SS the easiest to weld. One big factor to remember is to get as comfortable as you can so your hand and knees don't start shaking from over reaching. Just remember to back off the pedal if something goes wrong but give it a moment before you pull away so you don't contaminate he weld.

Just my 2 cents worth.

[tjenus]

One big factor to remember is to get as comfortable as you can so your hand and knees don't start shaking from over reaching.

this is so true, i try to drape the cable over my left shoulder to the right, hold the torch in the position i want it the stretch out all the way, then when i get into position the torch and cable are not bound up, if that makes any sence, also hold the torc with the tip of your fingers, not in the palm of your hands, thanks TJenus

[fusername]

thanks guys! I chopped a bit of scrap for myself today and am gonna try and slop it together and I'll post up my results. Wish me luck!