Help a Noob with Tig

admin

Hey yall...We just started tigging at my school, and so far, Ive just been messing around with it. I really like it, but I need some help. Ive been using a late model Syncrowave 250, 2% tungsten, and 1/8" cold rolled steel.1) how far out from the gas nozzle should I stick my tungsten? 2) How long of an arc should I hold? Coming from stick, where one burys the electrode, I'm having problems with getting my tunsten too far in and dipping it. Like, on pretty much every joint Ive tried. How close to the puddle should I hold the tip, and how do I know when im too close, or too far?3)How the heck are you supposed to gracefully move along a small joint on a rough table? The plates Im putting together are maybe 6" long, and I cant really figure out how to smoothly move the torch along. Any pointers?Thanks guys [Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:1) Tungsten stickout is 1.5 times the diameter of the tungsten. Basically the ground area should be sticking out.2) Arc length should be 1.5 times your filler diameter. When you dip, your puddle will grow about the thickness of your filler. If your arc length is too close, when you dip, your in the puddle. The arc gets really raspy when you get too close as well (for AC Aluminum that is, DC really does not make any difference in sound. I wear ear phones when I weld now, so I just watch).3) Practice. Pedal back enough to keep your arc and reposition your hands. I utlize my forearm on the parts to steady myself, then move the torch around with my wrists/hands. Try to keep as much of your hands free and off the part, that lends them to movement better.
Reply:With arc welding in general, diameter of the arc grows very rapidly with increased arc length.  So, a shorter arc length delivers the arc energy more efficently to the work piece in a smaller, more concentrated, spot size, giving a small controllable weld pool, the smallest possible heat affected zone (HAZ).  With a long arc, the arc power can be so diffuse that much of the energy is going into overheating the surrounding base metal, and not going into melting the weld pool.That said, hold the TIG arc as tight as possible without dipping the electrode into the puddle or hitting the electrode with the filler.  The arc gap is dependant on amperage, puddle size, filler size, joint width, etc., but in general you should be able to hold between about 1/16" and 1/8" arc length in manual welding.  In automated/machine TIG welds, we commonly set the arc length between 1/32" and 1/16".From what I've seen over the years, and here on the forum, it is a faily common mistake of new TIG welders to hold an excessively long arc, or just not hold a consistent arc length.
Reply:Originally Posted by pulserWith arc welding in general, diameter of the arc grows very rapidly with increased arc length.  So, a shorter arc length delivers the arc energy more efficently to the work piece in a smaller, more concentrated, spot size, giving a small controllable weld pool, the smallest possible heat affected zone (HAZ).  With a long arc, the arc power can be so diffuse that much of the energy is going into overheating the surrounding base metal, and not going into melting the weld pool.That said, hold the TIG arc as tight as possible without dipping the electrode into the puddle or hitting the electrode with the filler.  The arc gap is dependant on amperage, puddle size, filler size, joint width, etc., but in general you should be able to hold between about 1/16" and 1/8" arc length in manual welding.  In automated/machine TIG welds, we commonly set the arc length between 1/32" and 1/16".From what I've seen over the years, and here on the forum, it is a faily common mistake of new TIG welders to hold an excessively long arc, or just not hold a consistent arc length.
Reply:I agree with the others. However I find many students have issues at 1st with the "optimum" stickout and arc length, becuase usually they can't see the tungsten well enough untill they get the basics down. Usually we have them use about 1/4" to 3/8" stickout with a #8 cup, and hold about an 1/8"- 3/16" arc. Usually that lets them easily see the arc and not dip the tungsten as frequently. They can tighten up once they get the feel for the basics. I will agree most have the oposite issue holding too long an arc, but again usually it's because they can't see what they are doing. As far as movement, don't be afraid to take the grinder to the table if the school will let you. The stick/mig guys weld all over the work surfaces and just break off the coupons. That usually leaves the surface very rough with lots of sharp edges. I usually have the new tig guys grind the pi$$ out of the surface and edges so they have a nice smooth surface that doesn't snag things. Also try and be as comfortable as possible and use whatever is available for support. Lean on the table, wall, column etc if you need to..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