Tig Welding 1/8" steel

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I am planning to weld some 1/8" thick 1x3 rectangular hot rolled tube for a upcoming drill stand project, mostly fitted butt welds with no gaps. What is the proper technique to tig weld this ? I understand there is no bevel required. What about the filler rod ? Should I bother with a rod for tight fitted butt welds ?
Reply:Wrong. Bevel it correctly. Who told you not to bevel?Yes you have to add rod. ER70-s2 is cheap and abundant.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Oh yeah. You may want to descale and degrease too.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:If its regular carbon, use ER70-S2 or S6 with a 3/32 RED tungsten, on about 90-100 amps.  Grind all the millscale off till shiny metal. I would add rod it will make for a stronger weld joint. Heck you could even put a slight bevel on the 1/8" thick steel, at about 95-100 just move quick with the higher heat.  What is your welding skill.Miller Maxstar 200 SDPiperliner #10 Gold
Reply:Originally Posted by 1DucI am planning to weld some 1/8" thick 1x3 rectangular hot rolled tube for a upcoming drill stand project, mostly fitted butt welds with no gaps. What is the proper technique to tig weld this ? I understand there is no bevel required. What about the filler rod ? Should I bother with a rod for tight fitted butt welds ?
Reply:I'd suggest filler. Filler does more than just fill gaps. It also contains additives that help to remove some contaminants as well as alloy the joint to gain strength. Stainless is one of the few materials that welds well without filler. Steel is really isn't. I wouldn't count on simply fused joints for real strength. I've seen plenty simply crack on cooling if not done right.How skilled are you at tig. The reason I ask is but joints are some of the hardest flat material joints to do well. Tight butted joints are probably the hardest of the but joints. I'd suggest either gapping the pieces or beveling myself vs tight but joints. the reason is on a tight but joint you need a fair amount of power to blast thru the material and not just lay the bead on top. there is a very fine line between enough power, too much, and too little.Gapped  joints are a bit easier then tight butted joints as you have the thinner edges that melt a bit easier, yet the mass on each side to help when you need to cool the material down from getting too hot. Your filler takes care of the gap, and the gap also gives you a smoother finish as there is somewhere for the extra material to go.Beveled joints are even easier, either gapped or tight butted. Because you can get the root really small, it's easy to get full penetration without blowing thru. The extra mass helps cool the puddle and give you somewhere to go if things start falling apart on you. Again like the gapped joint, the open area gives you plenty of space for your filler so you get a nice smooth bead with limited excess reinforcement.I see plenty of students who think tight butted joints are the "easy " way to do this. They usually can't manage to get decent results and come ask me to adjust their machine. After I use their settings to do the weld, and do it right, I show them how to do the other two. Almost all the time they come back to me later with semi decent beads using a tight butted beveled but joint with just a tiny land at the bottom so the pieces fit together easily, and tell me how much easier it is to do it the way I showed them..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Great feedback !!!! Thank you very much !!!I was under the impression that I don't need to bevel 1/8", at least that's what I've seen in some welding publications. I am very green when it comes to welding, I've been practicing a bit and I feel confident to actually build something with my green skill set. Considering all replies, I will bevel the edges, I am thinking 35 degrees (?) and I will leave a tiny gap between the pieces. Millscale will be removed with a flap disc or muriatic acid dip and wiped with acetone just before welding. I have a choice of 1/16 and 3/32 tungsten and have a bit of 1/16 and 1/8 ER70S2 rod. Which combination do you recommend ? Once again, thank you for your input. I really appreciate it.
Reply:1/8" rod is way too big for that, go with 1/16".As far as "needing" to bevel, you don't have to, but it makes your life so much harder for no reason. That is especially true for someone with limited skills. Why make life hard?.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Not to complicate matters but I'm thinking a newby would get along better with the larger rod.  1/16th would involve rapid feeding whereas the 1/8th would be the simpler lay wire technique.  This is copied from an earlier date......The pictures show 3/16th plate with a gap just tight enough that a 1/8th rod won't fall through. Done on the flat. Numbers are amp settings I experimented at. (probably recommend 75-80 for the 1/8th steel). Lay your rod in the groove and strike your arc. Keep your torch in motion, a few slow weaves across the end of the rod from edge to edge and you'll see it flatten as it melts. Now continue weaving along your rod at a speed that is just fast enough to keep the rod flattening out. With a proper fit up you shouldn't have to worry about intentionally key-holing but you are bound to blow through until you learn the proper travel speed. When that happens, momentarily aim your torch a little higher up one of the bevelled edges while you move your rod closer to butt it up with the existing root.Last edited by OldSparks; 09-17-2014 at 01:11 PM.
Reply:I'm with everybody else... bevel,clean, fit, clean,weld... Clean is verry important!Also if it were me I'd run about 100 amps and controll you weld with your speed, that way you know you'll get decent penetration. If you have tried the lay wire technique before, it would probably serve well for you if you run higher amps (constant fill rod in the puddle acts like a heat sink and you must adjust voltage accordingly). If you have not tried it before I'd stick to the dabbing technique. It also may help you out to leave the tungsten out a bit farther than normal, this lets you get a better angle and view of what your doing in corners.If you run the 1/8 filler rod you will need to be aware that your puddle will cool down rapidly as you add filler. The step and pause technique helps when using large filler and low amps. (Normally you would use the same size filler as your tungsten, but 1/16 tungsten is too small for 1/8" plate). If your quick enough 3/32 tungsten and 1/16 filler will do a fine job!Real welders know how to penetrate!(Equipment)Whatever can be used to beat my opponent into submission!
Reply:Hello, 1Duc,I agree with Doug (DSW) on the filler. I have been learning and practicing TIG for over a year and as a hobbiest I recommend you use the 3/32" tungsten and the 1/16" filler. You will be feeding the rod pretty fast but the puddle won't cool too much. When learning, I think we tend to use less heat and move slower than the pros. And yes - bevel. It will help make a stronger and better looking joint.Let us know what works for you.Burt _____________________Miller Syncrowave 250Millermatic 211Miller 375 Plasma Cutter Hobart Handler 12010FtDrillBit.com