TIG'n across a gap

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hey all...so at work i pretty regularly come across rather large gaps.  we work with only sheetmetal, usually 18 or 16 gauge, sometimes up to 14 gauge.  the fab guys suck and fit up is usually pretty bad.  so my question is...whats the trick to getting that nice stack of dimes look on a gap with the TIG process?  im working with 3/32 2% thoriated tungston, and 3/32 rod, on mild steel.  the gaps are up to 1/8 of an inch.  i can lay a bead down that seals the oil pan up sufficiently and the company has no complaints about the way the welds look, but they definately arent as pretty as i would like them to be...anybody have any insight?  tips tricks?  i usually just keep the heat centered on the gap, as long as it keeps the edges of the weldment wet, and work the rod back and forth across the gap, but sometimes i have to move the torch back and forth across the gap just a hair before i dip the rod.
Reply:I am not going to lie, I have filled some hellashious gaps beforeMy methond to making them look good and make them as structuraly sound as possible *(if there is such a thing) is to have a constant filler feed with one hand as I move the the torch side to side (usually in a U motion), constantly feeding in the filler as I consistantly move side to side with my other hand and closing the gap or hole at a constant rate.I am always suprised how well they look, then I yell at the freshman and whip em with the filler if they really deserve it.  Force behind whipping is proportional to the size of gap they leftMechanical Engineer
Reply:Are you using ER70S-2?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by BLUE2KSSI am not going to lie, I have filled some hellashious gaps beforethen I yell at the freshman and whip em with the filler if they really deserve it.  Force behind whipping is proportional to the size of gap they left
Reply:Punkrider, you can also use backers, like copper or even aluminum blocks. You can weld right over the copper, and it will suck the heat out so you can get better looking welds. I would be talking to the man upstairs about getting better fit-up than 1/8" if I am having to weld on it.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:david-yeah im using er70s-2blue-i like that idea...def gonna try that tomorrowas far as the copper and aluminum backers, its not really posible since im welding on 3-d oil pans...unless i were to find a really small piece and clamp it to the inside...and i have complained to the higher ups...apparantly they are more concerned as to the speed at which the job is done rather than the actual quality...leave it up to the welders they say, then they complain when it takes us longer than it should to do our part of the job...save a little with the fab guys, but it comes right back when it gets to tacking and welding and finishing...i just cant give in to the "quickness" they want, i take too much pride in anything that my hands touch
Reply:Start recording how much time it takes you to re-fit/weld the massive gaps they leave, compared to one thats properly fit.  That ought to get their attention.
Reply:phaa, we work with 24g 304 and 316 (60 Grit Dull finish) Stainless Steel and regulary get bigger gaps than that, if the Turret punch has thrown one. Luckly all the joints are ground back and the grain put in. As others have said, big rod, and side to side torch movements.Zapster, doesn''t have the sole rights to all the fun jobs
Reply:You could try laying a piece of rod in the big gap and weld it in there too.  I have done that and it works.   Make the rod part of the weld.David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:What size of cup are you using?  For that I'd use 7 or 8 and just walk the cup.
Reply:Ahhh, idjits thinking that faster sloppier work in the earlier phases/production-steps is somehow going to mean a better production rate or magically a 'better' product at the end of the line.  Pffft!About the same kind of thinking as bean-counters thinking that 'saving' a few pennies on cheaper supplies but not considering the labor costs involved with that so-called 'savings' for all the extra labor and rework, etc, etc.Now, where was I?A 1/8 inch gap on some sheetmetal?  Jam a 1/8 inch filler rod in there to fill the gap, then grap another filler rod and the torch and weld all of THAT together.  That will only work if there is 'space' to have 1/8 inch of rod 'deep', it won't work for a smooth butt joint on 18 gauge sheetmetal."Gee boss, if the fitment is sloppy we have to go through TWICE as much filler to do the job as if the fitment was correct."Or you can run a 'gap-closing' bead length-wise on both sides of the gap until the gap is gone or you can bridge the remaining smaller gap and THEN you weld all of it together.Or you 'locally' do the gap-filling bridge at your 'start' (start puddle on one side, dab filler, jump arc to other side and start puddle, dab, jump back to first side and repeat until you can get both sides to 'meet in the middle' and actually have something to weld to instead of air) and then you repeat until done (side-side-middle ,advance, side-side-middle, advance, etc)."Gee boss, if the fitment is sloppy we have to go through twice as much filler AND the welding takes three times as long as it would take if the fitment was correct."Production cost of the sheetmetal whether sloppy or correct would be about the same, time and material wise.Production cost for the welding steps with sloppy fitment could be double or triple what they could/should be.And sheetmetal costs a LOT less than filler rod, on a pound-per-pound basis.Idjits.  The best laid schemes ... Gang oft agley ...
Reply:MOONRISE is right !Talk to your boss and tell him how much argon costs and filler rod etc.,.If the customer sees the sloppy workmanship the word will get out too.You have to have good ft up to do good welding.Many times bosses are big picture people and do not notice details.Not taking care of details can cost you a lot of business.Like a car repair customer that gets a car back and there are greasy hand prints on the car or interior. Coud be the last time the customer does business with you.Just think what would happen if your competitor  sees the sloppy workmanship.Here is the perfect example:American car manufactures used to have poor fit up.When the Japanese found out, they made a car TV commercial that showed a ball bearing rolling down the crack of the engine hood and fender on both cars.GAME OVER !!!Last edited by Donald Branscom; 12-11-2008 at 03:14 PM.AWS certified welding inspectorAWS certified welder
Reply:I remember that oneThats a good example weld it like you own it
Reply:Pulse (have it humming) and walk the cup.I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.