Tig welding tips for small tubing joints

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Hello, I'm making some small frames for a guy out of  1" .120 wall DOM tubing. Normally I mig weld them, but this guy wants them tig welded. I've Tig welded quite a bit but not many small tube joint. Looking for tips on electrode size and filler rod size. What size should the fillet be on 1" tubing? All the welds will be able to be put in any position, has the frames are not very big and can be rolled around on the table.Thanks
Reply:1/16" electrode, sharpened, possibly with a flat on the tip (crayon-tip profile).3/32" or 1/8" filler rod, depending on how wide you want your weld beads.  For max strength a fillet should have leg width equal to the tubing wall thickness (.125") and not have a concave profile.  Watch out especially for no undercutting.  (If you are undercutting, introduce filler rod to the weld bead sooner, and feed the filler rod more quickly.)If you want to get a nice looking "as welded" finish, with some rainbow oxidation film colors, as the customer may desire as he specified TIG for possibly aesthetic reasons, use techniques to minmize heat input, such as, using pulsing, doing your welds in short stitches, jumping around to different areas while allowing the work to cool in between.  And of course hold a tight arc to get the puddle to flow just where you want it.  Use only enough bead thickness for adequate strength.  Also use a large gas lens cup and sufficient post flow to allow the weld bead to cool enough to stay silver or to obtain the desired color.
Reply:You can use 1/16" tungsten and 3/32" will work fine as well. I totally disagree with using 3/32" or especially 1/8" filler. Try 1/16" filler as it wets out much better and you can move faster therefore creating a narrower haz.
Reply:i would use 1/16 tungsten & .045 filler.
Reply:WOW !   You are calling 1 inch .120 wall  SMALL ???????????I have a project comming up using 1/4 inch diam. .035 wall CM...........1 inch would seem like welding a dump truck bed !!!!!!!!!!!!Try keeping the tungsten 1/16 off the work if you can- you may have to steady with your littlefinger.  1/16  for a smaller bead.  or 3/32 if you are carefull not to pile it up too deep and wide.
Reply:I welded up a bunch of stainless steel restaurant chair frames this week that had bolted connections that were stripping out and failing.  It was generally .049" wall thickness tubing, in round diameters of 5/8" and 1" round, and some 1" square (under where the seat cushion goes.)  Some of the joints had nice tight fit-up and were not at acute angles, and didn't need a lot of filler.  The 1/16" filler rod I was using worked well for these joints.  Other joints had either poor fit-up (gap of 1x tubing diameter or even more) and in these areas I felt I would have benefited from larger (3/32") filler rod.  I had some .045" filler rod, but no way it would have been very fun to use on those gapped joint fit-ups.  The other joints I felt larger filler rod would have benefited were ones where I had a very acute angle groove to fill up with lots of filler.  No way I could reach the tungsten down far enough to do neat and tidy tiny little beads when you're talking about two tubes joining at a tangent.  (Generally joints where two pieces of tubing, oriented at a 90 degree angle to each other, just touched each other and required an "O" shaped weld bend be deposited around the joint.  The 1/16" filler rod worked OK for these as long as I fed it quickly enough so didn't melt through.Here is one of the pictures I snagged on them, after some course grit polishing.  Unfortunately, I didn't get many pictures.  I got my welds looking really good by the later ones I did.  I will probably be doing one more batch of them.But anyway... these are about 1/2-1/3 of the wall thickness of the tubing the OP was going to weld, so I think 3/32" filler would be well within the range of what would be appropriate for his specified thickness of tubing.  Unless your doing very small weld beads with very tight joint fit-up, in which case a small diameter rod would be ideal.  If there is any gap in the fit-up, the small filler rod may become a big hassle.One technique I kind of liked and wished I had more opportunity to play around with more was back feeding the rod.  (feeding the rod in from behind the weld bead.)  I noticed it could really increase travel speed when it could be used, because it seemed the movement of the rod would help flow the liquid puddle out ahead of the joint and allow the bead to progress more rapidly.  Very cool.  But there were only certain opportunities where I could use it, often times inadequate vision would limit being able to use this technique. Attached Images