Having real trouble with TIG stainless welding vertical

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So, I'm taking a welding certification where a work to qualify me to weld carbon steel to stainless. I have to pass X-ray and bend tests on 2g, 3g and 4g plates. Beveled quarter inch, and I forget the thickness of the backing strip. I welded my 3g plate, root pass looked great, fill passes were solid, but the cap was absolute TRASH. Literally looked like you gave a chimp a mig gun, and I was welding TIG. I was walking the cup, and no mater how fast I would move the metal would flow down, and I couldn't get even half decent gas coverage. I have the AWS certification for vertical TIG 3/8 plate, Walked the cup and everything, welds were great. Why am I having so much trouble with stainless?
Reply:Amperage? Pictures? CFH? How thick is the steel? Filler size? Filler alloy? Did you let it cool before doing the cap? Electrode type/ fresh grind? Cup size? Electrode stickout? Arc length? You need to tell us more so that we can give advice.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:130 amps, I will upload a picture soon, 30 cfh 100% argon, 1/4 inch plate, 3/32 309 rod, I didn't let it cool, stupid mistake. Freshly ground thoriated tungsten, Number 7 cup, I couldn't tell you my stickout exactly, but I would say 1/8 of an inch. I tried to keep a tight arc, probably not tight enough, just didn't think that much about it.
Reply:30cfh on a #7 cup is high argon flow for such a small cup 15-20 would be more like it. I would use an oversized large cup #12 or 1 1/8th gas lens with 30-35cfh for good shielding
Reply:If you only had 1/8" stickout and a #7 cup while walking the cup I'm guessing that your arc length was too long. That will cause lots of trouble. You need enough stickout so you can keep a tight arc and be able to see when the torch is laid back a bit so you can rock it for forward progression. 30CFH is a bit high for a 7 cup but it shouldn't be a problem.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Ok, I definitely concluded gas coverage was an issue, considering the appearance of the weld. I think the biggest cup I've got is a 9 so I will buy a larger one. About how much does a bigger gas lens cost?
Reply:Walking the cup is definitely a very new skill for me.   I've only done it one other time and that was on my AWS 3G 3'8 plate test. I've only been welding for a little under a year and  I'm starting to realize stainless is quite a bit more difficult that carbon steel.
Reply:Check out arczone, gas coverage is definitely your issue. Get a #12 gas lens setup or Pyrex whatever you prefer. The prices varyinadequate gas coverage I think is your problemLast edited by That Guy There; 08-03-2014 at 08:37 PM.Millermatic 211Miller Syncrowave 350lx with cooler and tigrunner Thermal Dynamics cutmaster 811955 National Cylinder Gas O/A setup with original patina
Reply:Gas coverage should be fine with a #7 cup, unless you are weaving really wide. Overheating the steel with a long arc and slow travel speed is likely your problem with the way it looks.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Thanks for all the advice. Thoriated tungsten is good also? Besides the radioactivity.
Reply:Yep thoriated is fineAirco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Originally Posted by SquirmyPugGas coverage should be fine with a #7 cup, unless you are weaving really wide. Overheating the steel with a long arc and slow travel speed is likely your problem with the way it looks.
Reply:Alright, Welded another plate and it looks much better. Now my issue is horizontal, and overhead! Any tips on these positions? I'm having trouble with overhead the most.
Reply:For overhead, wrap your legs around the tube and hang from it. Just like welding flat then. Honestly when tig welding there's not a huge difference in the way it welds when changing positions. Just have to get comfortable and pay attention to arc length/ work angle/.. You get the picture.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG