Tig troubleshooting

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Gday guys,Recently i was asked to do some SS tig at my work, ive done a little tig here and there and i'm also certified in tig pipe but i got that ticket about 2years ago and havn't used it since. My company is predominately structural fabrication mostly mig and some site arc work so im pretty limited in my knowledge as far as tig welding goes, add to this me being the only qualified welder at my company so i have no one to go to with questions and querries.So this is where you guys come in, i dont think it turned out to bad, but it's certainly nothin to be proud about. My goal in welding is aim to be exceptional not just acceptable.Thanks in advance for any help you guys may offer.It was a corner but joint on 2mm 316SS, 2.4mm (i think) red tungsten with 2mm 316 filler, running about 45amps (i will also add the fitup on the joint wasn't the greatest in some areas, but that wasn't my doing as i only welded not assembled)Last edited by rbadger86; 01-12-2014 at 04:24 AM.
Reply:I'd really need to see better picts of the bead, but it looks lumpy and cold to me. Also that grey color is often indicative of stainless that lost it's shielding before the material cooled enough. That would also be a sign that your amps were too low and you "cooked" the material.It often seems backwards to many guys, but more amps going faster puts less heat into the material. Also with stainless you need a good gas shield. A large gas lens can often make sense to extend your coverage.I make out 2mm to be roughly .079". Typical rule of thumb is 1 amp per .001", so you ought to be up in the 70-85 amp range roughly if my math is right. You should end up with a nice rainbow or straw colored stack of dimes look. You can "cheat" and make your life easy if you set up a piece of tube on that bench you can rest your torch hand on as you go so all you have to do is slide your hand down the length of the weld. A joint like this also works well with a lay wire technique if you aren't used to feeding filler. Just lay the filler in the V of the joints and slide it into the puddle or bring the puddle to the filler rather than "stabbing" the filler at the joint..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Looks like a guard of some sort, possibly food processing machinery. You can clean things up better before welding & turn the amps & travel speed up like DSW said. If you dwell the puddle with SS too long the outside skin gives up some chemistry.In any event, around here with food machinery even a rainbow look to the weld gets polished off. It all looks the same color or it's wrong with the food guys.Pay attention to what DSW said about getting your torch hand rested and comfortable. Also depending on things, looping the torch lead around your shoulder or forearm near the elbow will do a lot to keep the torch from feeling heavy in your hand & wrist.Then it's just practice & time = less clean-up & polishing.Matt
Reply:Thanks for the input guys, much appreciate it. I did a bit of thinking and i think i was actually at around 65amps but yes still too cold, my boss seemed to think that on this sort of setup that i shouldn't need filler at all and to just fuse the joint autogenously (i think thats how you spell it) however i was always told while doing my tig cert that you need filler to avoid cracking.The units are actually coolant dispersers for a plastic extrusion line, my boss wasn't concerned about how they turned out because there not really a crucial part, they actually polished up pretty well, more work than they should've been but we got there.
Reply:Stainless is one of the few metals you can weld autogenously under the right conditions. However with that joint setup, you'll really thin down the material to fill the joint if you do it that way. With a V joint like that with just the inside corners touching, filler is the way to go. If you brought the "top" out flush with the outside edge, then you could weld with no filler, but your amps would need to be higher to get the fusion into both pieces..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:i would say you need to move hotter and faster.    i agree with your boss on not needing fillerVantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Looks like your inconsistency is also due to stopping at tacks.  If you use a thin wafer disk to feather tack edges especially the leading edge, then you'll be able to blend them in nicer.  Like others said, get comfortable, use a base to glide on.  Good project to practice on.
Reply:try 60-80amps, 1mm filler (0.40), faster travel speed, you can leave rod in the pudle.
Reply:More amperage and be more consistent. I personally would use a filler rod to make a stronger corner but if strength is not a concern, tack the end about 1/4" long so it doesnt blow out, then start your weld, get right to full weld amps and rock and roll. When you start out cold and are scared of blowing a hole this is the weld you will get.
Reply:Cheers for all the help guys, i also forgot to add that i was using a lift tig with no foot pedal, ive used a pedal in the past and liked being able to adjust the amps as i was traveling, but yes i do believe fully that i couldve acheived a much better result with running hotter. Unfortunately there was only 7 of these and they didnt take long so i will have to wait another 6months before the next thin walled ss job comes along haha.Thanks once again guys!
Reply:Originally Posted by rbadger86Cheers for all the help guys, i also forgot to add that i was using a lift tig with no foot pedal, ive used a pedal in the past and liked being able to adjust the amps as i was traveling, but yes i do believe fully that i couldve acheived a much better result with running hotter. Unfortunately there was only 7 of these and they didnt take long so i will have to wait another 6months before the next thin walled ss job comes along haha.Thanks once again guys!
Reply:I like the edge to edge configuration and suggest a smaller filler size......All your doing is filling the area between the two edges to keep the material thickness the same....Too large a filler takes heat away from the weld joint and slows things down...http://im1.shutterfly.com/media/47b8...D550/ry%3D400/  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:I'll second all that BC said and add a few more. The bad thing about lift arc and tig welding you want to keep pretty is when you break arc you typically pull the shielding gas away from the puddle. You need to keep argon on the weld til it cools somewhat. One thing I've done in a pinch with lift arc or a dry rig is to rig my ground clamp so that it's near my foot and when I get close to the end of a weld I can simply kick the ground off to break arc and keep my torch and shielding where it belongs, over the weld cooling the weld. Another point is to keep the molten end of the filler wire under the argon coverage til it's not molten. For example if you pull your stainless filler out of the argon coverage while it's still molten you will contaminate it. If you haven't ever noticed just try it both ways. If you let it cool under argon the end of the wire will be nice and shiny if not dull gray.Last edited by Showdog75; 01-15-2014 at 06:56 PM.
Reply:at 60-80 amps you can pull back 1/2" and break a arc and still have plenty of gas flowing on the piece, all it takes is a quick wip of the wrist to break the arc and get the torch back 1/4" off the work piece.  A foot pedal is like a auto darkening hood, if you dont know what you are doing they sure make it easier to try.
Reply:Originally Posted by shovelonWhy are you not using a foot pedal? You will really appreciate the control it affords you.