Some Tig help with steel please

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Below are a few pictures of some welds I made tonight, I am hoping to get the following questions answeredSetup2% Lanthanted3/32 Tungsten#6 (3/8) cup/nozzle with gas lens100-115 amps DCOld Transformer Machine.150 CR mild steel with a quick buz of the sanding disc1/16 ER70S-2 FillerThe first and second pictures is the cosmetically the best weld I can pull off, the 3rd and 4th are as I turned up the amps trying to make a larger weld. In the process of upping the amps the welds go from shiny to dull grey. The web thickness in the first 2 are maybe .100 on .150 material, the 3rd and 4th pics it might be closer to .125, still no where near .150My questions are1. When doing a T weld (tig) on steel do the weld generally come out concave? I can not seem to get any of mine to come out flat or convex (like when I MIG weld). 2. Are Tig welds on steel generally smaller then "idea" welds. By idea welds I mean where the web thickness is equal to or greater then the thickness of the thinest material? I have seen several pictures on the forums where tig welds appear to smaller then the "idea" size. 3. What color should a properly done tig weld on steel be? Should it be shiny silver or is a dull grey ok?Thanks,Dan Attached ImagesLast edited by engnerdan; 08-26-2008 at 10:26 PM.OwnerDW Metalworks LLCMiller Trailblazer 302Miller 8RC FeederMiller Passport PlusMiller Dynasty 200 DX W/Coolmate 1Hobart Handler 135Hypertherm PowerMAX 30Smith O/A Torch SetPlus much much more
Reply:Dan, those look very good. Heat looks ok, maybe a tiny bit cool, but really, they are fine. The gray color is the gas coverage getting a tiny bit thin, but you are doing fine. Maybe a bigger gas cup will help for overall coverage. I would use bigger filler wire, try some 3/32". You should see a bigger weld with the bigger filler. I am currently welding an aluminum structure, and I am going through 3/32 filler like it was solder. I really could use 1/8 filler, but I already have 15lb of the 3/32, so I am committed to using it, just feeding faster than I would like. You could also use a slight weave pattern as you weld, but honestly, your welds look very good, and I would say only make small adjustments to them if any.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:Your welds look great, no problem, very consistent, good shielding, no undercut that I can really see, looks like you got good fusion to each plate.  In a fillet weld, you want full fusion to each plate and down to the very root of the joint, you do not need deep penetration beyond the plate surface or root of the joint, you only need complete fusion with the surfaces down to the root.As you infere, a flat or slightly convex fillet is preferable over a concave fillet, as the throat distance from the root to the face is the critical dimension for strength.  For your 0.150" thick plate, the 1/16" (0.0625") filler is too small for manual welding, too difficult to get enoungh wire in, so as Rojo suggests 3/32" (0.090") or 1/8" (0.125") should help on this weld.
Reply:Well I will try a larger filler tonight and see if I can't pull off a whole weld that looks right. I was starting to get frustrated. -DanOwnerDW Metalworks LLCMiller Trailblazer 302Miller 8RC FeederMiller Passport PlusMiller Dynasty 200 DX W/Coolmate 1Hobart Handler 135Hypertherm PowerMAX 30Smith O/A Torch SetPlus much much more
Reply:Originally Posted by engnerdan1. When doing a T weld (tig) on steel do the weld generally come out concave? I can not seem to get any of mine to come out flat or convex (like when I MIG weld).
Reply:Dan, how much stick-out were you using?I've just started learning TIG and it just happens I was trying to weld the exact same joint with the same thickness metals, current, etc and was having some real trouble. Only difference is I was using a #7 cup and a T/A 185 inverter machine.If I just run some stringer beads with no filler I can make some nice beads. Once I tried making a fillet weld and adding filler I had porosity like there's no tomorrow.I'm almost wondering if they gave me the right filler rods?
Reply:Originally Posted by EngloidDull grey is fine.
Reply:Originally Posted by turboguyDan, how much stick-out were you using?I've just started learning TIG and it just happens I was trying to weld the exact same joint with the same thickness metals, current, etc and was having some real trouble. Only difference is I was using a #7 cup and a T/A 185 inverter machine.If I just run some stringer beads with no filler I can make some nice beads. Once I tried making a fillet weld and adding filler I had porosity like there's no tomorrow.I'm almost wondering if they gave me the right filler rods?
Reply:The filler wire is a little large, use .045 Not 1/16.For 1/4 inch plate set your amps at 125. on the machine.When the rows of nickels start to look like there are many overlapping, that means the end of the tungsten is split or ragged and needs sharpening.Last edited by Donald Branscom; 08-29-2008 at 12:49 PM.AWS certified welding inspectorAWS certified welder
Reply:So my Dynasty showed up Friday and my foot pedal today, so I finally got to use it tonight. I do notice a much better arc quality over the old Lincoln I was using so that might have helped but I also tried some 3/32 filler, I got a much better looking bead but there really was not much pushing the filler into the puddle. I pretty much just was able to push it up next to the puddle and it melted in, not sure this is the right thing to do but it worked tonight. The first weld is as follows3/32 70S-2 filler3/32 Blue tungsten#6 gas cup/nozzle155 amps12CFHThe second weld was just the same but I used 1./16 fillerThese by far as the best welds I have done. Several more hours of torch time with this new welder and maybe I will be able to do it consistently. Attached ImagesOwnerDW Metalworks LLCMiller Trailblazer 302Miller 8RC FeederMiller Passport PlusMiller Dynasty 200 DX W/Coolmate 1Hobart Handler 135Hypertherm PowerMAX 30Smith O/A Torch SetPlus much much more
Reply:Originally Posted by tmorgan4I've kept wondering this exact question same question but hadn't gotten around to asking it yet.  Some of my beads come out shiny and some are the same dull gray you talk about.  I had a very experienced TIG welder look at some of mine and he pointed out that the dull gray bead is usually caused by excess heat.  What is your take on this Engloid?
Reply:Originally Posted by engnerdanThese by far as the best welds I have done. Several more hours of torch time with this new welder and maybe I will be able to do it consistently.
Reply:engerdan,What was the thickness of your plates?
Reply:Sorry missed the material thickness was 0.150"
Reply:[QUOTE=engnerdan;209551]My stickout depends on the joint type and how steady my hand is on the given day, the shortest I would run on this joint would be so that the tungsten would be about 3/32 from touching the corner of the joint when the gas cup/nozzle is touching both pieces of metal. This is my "crutch" setup when I am rather shakey. It keeps me from dipping the tungsten into the puddle. I generally have a bit more stickout and don't rest the cup on the metal. I will measure tonight and see what it actually is. As a newbie at tig I am following this and other threads and I am wondering based on what you said, what forward angle is the torch, or is that stickout distance straight on?  Seems that this dimension would be subject to the size of the cup. (I am assuming you are talking using a #6 cup as was the OP?Thanks for your great instruction!TimA rich man is not the one who has the most but instead one who needs theleast. Retired IUEC local 19AK Bush pilot,  Chaplain  CMA Chapt 26victor torchesMiller110v migDynasty 200dx (new in Dec 08)Hypertherm PM-45MM-252 (new 2/09)
Reply:Dan,Beads look fine to me.  The more you practice, the faster you'll become and, I suspect, much of the "grey" will go away.I would suggest trying a 1/16" 2% thoriated tungsten for that particular joint.  Think you'll find that with the smaller tungsten, arc starts are easier and the arc is more controllable.I'm with the majority here (counter to what some "experts" claim) in that the use of 3/32" filler would be recommended.  .045" filler sure as heck isn't going to help you achieve the convex bead you're looking for.I'd take Engloid's comments/recommendations to the bank.  He and KB are probably the best tig welders who post on this board.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:Dan,Those beads look great from my perspective!Sundowner,Hope this isn't a dumb question.  Do you make the size selection of the tungsten primarily by the ampres it will handle or the size of the bead/thickness of material being bonded?  Thanks,TimA rich man is not the one who has the most but instead one who needs theleast. Retired IUEC local 19AK Bush pilot,  Chaplain  CMA Chapt 26victor torchesMiller110v migDynasty 200dx (new in Dec 08)Hypertherm PM-45MM-252 (new 2/09)
Reply:Ultrachop,Amps, definitely.Smaller tungsten starts better, and, I find, gives me better control of the arc.Size of the filler and how you get it in the puddle will have more to do with the size of the bead.  More filler=larger bead.PS.  That's why the comment about going to .045 filler made no sense to me.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:Sundowner,Thanks for the clarifications.  (with no experience with tig I first was trying to feed 1/16" wire into my 1st attempt at 1/4" MS and it was quickly replaced with 3/32 so I didn't have to feed so fast!  (not that coordinated at best)  Let me add to the question.about Tungsten sizing.   With Aluminum welding with the Dynasty, using either Ceriated, Thoriated, or Lanthenated (dull pointed) on 1/8-1/4" material, would you typically use 3/32 or 1/8" tungsten?  I have been using 3/32" and it seems at between 125-145 peak amps I am pushing the limits of the tungsten to absorb the heat of the arc, as it seems to be somewhat unstable.   Am I all wet or just still just experiencing "Newbie" conditions?TimA rich man is not the one who has the most but instead one who needs theleast. Retired IUEC local 19AK Bush pilot,  Chaplain  CMA Chapt 26victor torchesMiller110v migDynasty 200dx (new in Dec 08)Hypertherm PM-45MM-252 (new 2/09)