Newbie - TIG - ???????????

admin

Alright I've only asked questions about machines and now I am getting into the welding itself. So long story short, I have a Miller Maxstar 150 STL, Picked up a torch, filler rod, and all the other odds and ends that I need to attempt to TIG weld. So I set everything up Machine Amps 80-105, 3/32 Thoriated Tungsten, 3/32 filler rod and set to work. So as I was trying to weld I would get the arc started work along, and the first problem I seem to be having is at the end of a bead I have a sorta Nipple sticking up off the bead. The other thing I noticed is that My weld beads seem to be like a dull grayish color. They are not all shinny like say some of the mig beads I have run. I guess I should mention that I am welding on mild steel, maybe 1/4 plate. flat position. Just trying to get a feel for the whole operation of all of this.Just curious what I am doing wrong. Also I will try to get some pictures of the beads up soon.
Reply:What you have is a crater at the end of the weld.  To finish a tig bead, slowly let off the pedal and give it a couple extra dips of filler rod as the puddle is cooling.  This fills the crater and keeps that 'tit' from bubbling up too.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:First off, the Maxstar 150 was never designed to tig weld 1/4" plate.Not nearly enough amps for the job.  Because you don't have the amps, you're staying in one spot too long and "cooking" the filler.I'd recommend you drop back to 1/8" coupons and learn the tig process properly.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIFirst off, the Maxstar 150 was never designed to tig weld 1/4" plate.Not nearly enough amps for the job.  Because you don't have the amps, you're staying in one spot too long and "cooking" the filler.I'd recommend you drop back to 1/8" coupons and learn the tig process properly.
Reply:Originally Posted by SundownIIIFirst off, the Maxstar 150 was never designed to tig weld 1/4" plate.Not nearly enough amps for the job.  Because you don't have the amps, you're staying in one spot too long and "cooking" the filler.I'd recommend you drop back to 1/8" coupons and learn the tig process properly.
Reply:Alrighty then, Maybe I was a little unclear, I am just running practice beads on a piece of 1/4 steel I had floating around in the garage. But in my haste to post last night I may have forgot about that part. If I am understanding what you have all said. I should go out and get some 1/8" and actually fit up various joints and that should yield me better result. Also I should speed up my movement just a little bit.
Reply:Pulser,Laughing!!!If all I had was a Maxstar 150 and 1/4" plate, the first thing I'd do is bevel the plate, stick a rod in the stinger, and go for it.But here we're talking about a "new" tig welder.  He'll find learning tig a lot easier if he's dealing with coupons more suitable for his machine.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I'll agree with sundown, there's not much point in practicing on very thick plate when you start off tigging, because it's gonna soak up the heat and act a little different than what most people would actually work at. And you would have to be near nuts to try to weld 1/4" plate manually in one pass, and think about getting good penetration AND crown and wetting etc.I think the guy was talking about just running bead on plate. Which is a good way to start and get a feel when I learned I spent about maybe an hour practicing just making a molten puddle then running a bead straight free hand with no filler. After that I did the same but with filler to get a feel for dipping, finally I started on joints. It helps to actually have a joint to run and see how it comes out.The dully grey means the weld is getting oxidized. mostly likely you're traveling too slow/ heat is too low and the material soaks up a bunch of heat and stays above it's oxidation temperature after it leaves the trailing gas.   The solution is to move faster, or start looking for leaks.I would suggest running some beads on thin gauge around 14-16ga and make the metal is very clean as that's what tig likes.Welding EngineerCertified Scrap Producer