TIG Fillet Welds on 1/4 MS

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I have been working on the fill technique for welding fillet welds.  I have attached some photos of some 1/4" MS welds I had done.Are the weld beads what you can come to expect on mild steel or can you get more of the dime look like on SS?Does anyone have a photos of their TIG welds on mild steel so I can compare?Please give me some advice on which is the best and what I can do to improve.  I was using a PT 225, 3/32 Tung. Orange, 3/32 Filler, 230A and I did not need the full pedal.Thanks in advance!Last edited by David R; 12-28-2007 at 06:29 PM.Reason: fix picsBuild a Barstool Racer at BarFlyRacers.com!
Reply:Those will work, just push a little farther, then dip. It looks like you're pushing and dipping at the same time.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Malich,Just how much amperage are you using, factoring the amount you press down on the foot pedal?Would you estimate you're using 50% of the pedal, and therefore about 115amps?  Or more?  Or less?I ask because your bead looks flat or slightly convex.  I'm wondering if you're using excess current in an effort to try and travel faster....I think this because I can weld 2" schedule 80 pipe, which has a wall thickness slightly less than your 0.25" plate, with about 90 amps.  I use 1/8" rod and the full 90amps to make these welds.  I can see the Fillet weld requiring more heat input than the pipe weld I'm refering to, but not 250% more amperage.  Seems to me that ~110 amps with 3/32 filler rod would be more than sufficient...After reflecting on Miller's welding parameter recommendations(see below), I"m also wondering if you should be using a larger diameter filler metal rod for this joint.  This might also help to improve the bead profile and make it easier to control the puddle....(Note: I'm not sure I agree with these recommendations, but just listing them as a reference point to start from)Are you free-handing the torch while running the bead?  Or are you 'walking the cup'; by resting the edge of the cup on the base metal and moving it forward using a rocking motion?Have you tried using a lay-wire technique, vs dipping the filler metal rod into the puddle?  I feel that lay-wire is somewhat easier...Miller's TIG calculator (http://www.millerwelds.com/education...calculator.php) reccommends:Tungsten Electrode Diameter:1/8" (3.2 mm)For steel and stainless steel, use a 2% thoriated tungsten, AWS Class EWTH-2 (red band). Prepare a pointed-end.Torch Cup Orifice Diameter:1/2" (12.7 mm)Use ceramic cup when welding with less than 250 amps. Use water-cooled torch when welding with more than 200 amps.Filler Metal Diameter:3/16" (4.8 mm) Polarity:DCEN (straight polarity)Amperage Range:250-325For mild steel, increase amperage 10%.Gas:ArgonGas Flow Rate:13 cfh or 20 psiWelding Speed:5 inches per minuteLast edited by A_DAB_will_do; 12-28-2007 at 04:07 PM.
Reply:What I was actually doing is moving slow and dipping a lot to build up the joint.  I moved maybe a 16th of an inch and dipped 3 or 4 times to build up the filler.I think I am using about 50% of the pedal and maybe I am moving to slow in an attempt to build up some heat in the joint.  I have my arm rested on the table so I can keep a good distance and move in a straight line.I have not tired laying the filler in yet, I will try that next along with walking the cup, I forgot about that.I may need to move faster and turn down the heat a little I think...Build a Barstool Racer at BarFlyRacers.com!
Reply:Try moving slower and learn to really look at the puddle to control your heat.Also dip less, but use a smaller wire and add more at once.I dont know if ive ever used 3/32 wire unless it was for building up a worn spot on a shaft.  Usually I stick with 1/16 or .045Have we all gone mad?
Reply:If you want my opinion I would tell you to work the pedal more. If you re just making nice welds and not doing production,pumping the pedal will give good results. I suppose it would be like having a pulser but you use your foot. Pour heat on add rod back off repeat as needed.All other parameters seem ok.What is the orange tungsten? I have used Red (2% Thoriated) for everything and I am a tool & die welder and weld tool steel and other exotic metals.
Reply:I think they look good.  Don't worry about the stinkin dimes.  They will come with time.  Just lay down a nice bead.  If it looks like you did it with stick, it will be a good weld.  I think the toes could be a little wetter (too much filler).  Most tig welds come out concave in a fillet.  You could also make a second pass if needed.  All you need is more practice.  Burn up a bunch of filler, work on consistency.  Those are nice welds.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:SIDETRACK/SIDEBAROrange is Ceriated tungsten, which is a non-radioactive alternative to the Thoriated tungsten you're used to.  It's almost as good as the Thoriated so far as currently carrying capacity and durability are concerned.I have, and have used, both.  I can't see a big difference.  YMMV. Originally Posted by welderman1If you want my opinion I would tell you to work the pedal more. If you re just making nice welds and not doing production,pumping the pedal will give good results. I suppose it would be like having a pulser but you use your foot. Pour heat on add rod back off repeat as needed.All other parameters seem ok.What is the orange tungsten? I have used Red (2% Thoriated) for everything and I am a tool & die welder and weld tool steel and other exotic metals.
Reply:Ahhh.  FWIW, David R is right.  Functionally the welds you showed are probably alright.  If you need welds with perfect appearance, then keep practicing.  I still recommend going to a thicker filler wire.  You won't need to dip as often, staying in one place so long.  I think you're trying to make the bead too wide in one pass with the filler rod you're using.  Dipping 3 or 4 times at each step is just allowing the heat to spread the puddle out further and further.  While I'm thinking of it, try shortening your arc length a little bit as well.  This will help keep the puddle from spreading out excessively, make the bead more convex, and enable you to travel faster.  Try to keep your arc length less than 1/8", if you aren't already doing this.  1/16" or 1/32" would be better.  If you're like me, you'll have trouble judging this absolutely, and probably need a magnifier lens for your helmet.  Just try and get the arc to be as short as you can without sticking the tungsten or hitting the tungsten with the filler rod.If you want the weld bead to extend 1/4" onto each plate(AKA have 1/4" 'legs'), using 3/32" filler rod, you should probably run 3 narrower overlapping beads.  The final appearance of the weld should be better and the welds will be easier to make.  It'll just take 3x longer.    Originally Posted by malichWhat I was actually doing is moving slow and dipping a lot to build up the joint.  I moved maybe a 16th of an inch and dipped 3 or 4 times to build up the filler.I think I am using about 50% of the pedal and maybe I am moving to slow in an attempt to build up some heat in the joint.  I have my arm rested on the table so I can keep a good distance and move in a straight line.I have not tired laying the filler in yet, I will try that next along with walking the cup, I forgot about that.I may need to move faster and turn down the heat a little I think...
Reply:Thanks for the tungsten info. I like my tungsten RADIOACTIVE.To the OP when you com to the end of the weld slowly let off on the heat. The stop is one of the first plces for cracks to start.