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Learn to tig weld.


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I didn't see much here on learning basic tig, so I thought I'd post up some material I've done before when asked these sorts of questions. I'll add threads on mig and stick later. If you want specific help with your welds, I'd suggest starting a new thread rather than cluttering this one.


A bit 1st about myself. I help teach basic welding in the evening program at one of the local votech schools for the last few years. I'm not an "expert" by any means, but I've been told by several instructors at a couple of schools that I have a real knack for getting across the basics to students. What I'll cover is the way we teach new tig students at the tech school.

1st go on line to Miller and download their tig handbook as well as the manual for your machine. Read thru them and they will answer most of your basic questions on this. Miller used to have a really great free PDF step by step instructional guide to tig welding, but they unfortunately have dropped it from their website. The current link covers some basics on torch angle and so on that's easier to explain in picts vs text. ( If anyone has the old downloaded copy to post let me know. I lost the copy I had on my old computer when it crashed and didn't bother to resave it since I thought it was still up on Millers site)





I'd suggest starting of learning DC tig on mild steel. I know some suggest learning alum right away, but I've found that most students learn the basics faster with steel since it's more forgiving. Heat control on alum is critical and you almost need to make corrections before things get out of hand. With alum, if things start to go bad you usually need to add more heat and go faster, the opposite of what most people want to do. Trying to go faster usually trips up new students and the crash and burn. This frequently frustrates students. I find if students learn the basics on steel and get them down cold, alum isn't too hard to transition to later. The nice thing about steel is if you start to get out of control, you can usually slow down and back off the amps until you have control again, and then continue on.

For purposes of this, I'll assume you are using a dedicated tig with a remote pedal to control the amps. If you are using a DC power source with no pedal, the drills are similar, but I'll cover the differences in another post.

Get yourself some 1/8" steel ( we use 3" wide 6" long pieces) and grind/sand off the mill scale, both sides preferably. If the steel is oily, you'll also need to wipe it down with acetone ( do not use brake cleaner!) You can skip the grinding if you buy cold rolled rather than hot rolled, but CR is more money. It's usually cheaper to grind. Note a wire wheel will not remove rust or mill scale, only polish it. You need to grind sand to prep. Unlike mig or stick, tig is does not tolerate contaminants well. Clean metal solves many issues students have. Thicker steel tends to give students a false sense of control. Thinner material than say 14 to 16 ga tends to blow holes in it too fast if you can't control the heat. 1/8" is thin enough to soak up excess heat, but thin enough that you can still melt thru if you aren't careful.

Get some 3/32" red tungsten. You can also use ceriated ( what Miller packs with new machines) or Lanthanated ( a good all around tungsten for alum and steel/stainless.) Red just tends to be cheap and readily available. Grind your 3/32" tungsten to a pencil point grinding with the wheel, not across it and set the machine at roughly 125 amps on DC, argon at about 15-20 cfh. Extend the tungsten out of the cup (#8 works fine) about 3/8" roughly. This will let you see the arc better. If you have access to a gas lens rather than a standard cup and collet assembly, I'd recommend using one. These allow you to extend the tungsten a bit farther and still maintain good gas coverage. This makes it easy to see the tungsten and helps avoid dipping the tungsten and constantly needing to grinding. Get used to grinding... you'll be doing a lot of it at 1st.

1st drill I usually have students do is to just run beads with no filler on flat plate. Try and get comfortable and set up so you can maintain a consistent arc length and travel speed across the piece. Try and keep the tungsten about 3/16" up from the material as you go. You will be using the pedal to manipulate the amps in this drill. As you run the beads, play with the pedal to get a feel on what happens as you depress the pedal. Make the puddle smaller and larger at will.

Remember the plate will heat up and if you don't keep cooling it down, it will act like you are upping the amps. I tell students the pieces are cool enough when you can handle them with your bare hands. A quench bucket and several pieces to work with will allow you to keep practicing without having to wait all day for coupons to cool between beads. When you dip the tungsten in the puddle, STOP. You need to regrind. Orange "dust" around your weld usually is an indicator you dipped and didn't stop to regrind.

Next reset the amps to say 90-95 and floor the pedal. In this drill you will now vary either the distance you have the tungsten from the work, or your travel speed ( drill #3 is to vary the one you didn't do in this drill) Get a feel how these changes affect the arc and puddle. Don't worry too much about these right now, the idea is mostly to get you to understand that varying these will change and effect the puddle. For most of the rest of the drills, you'll want to try and maintain as consistent travel speed and arc length as possible and just change your amps with the pedal. Remember to cool your pieces and to regrind when you dip.



When doing drills from this point out, it's important to remember to try and keep everything as consistent as possible to limit variables. I usually suggest students rest their torch hand on the table and slide it along as they go to maintain a constant travel speed and arc length. It's critical to do this as much as possible. As you saw with the drills above, changing these things will affect your welds. Trying to limit the variables makes it easier to learn.



After these drills, say maybe an hour of "play time", try to run a bead by adding filler. 1/16" filler is a good size to work with using steel. I usually suggest the students start with a lay wire method where they keep the filler in contact with the plate, and bring the puddle to the filler. It's important to remember that you melt the filler with the puddle, not the arc. You can slide the filler along the plate and into and out of the puddle as needed. If your amps are on the low side, some times the filler rod tends to be "sticky" and want to stick to the plate using this method though. Add a few more amps with the pedal if this is the issue. You can also "tap" the filler in like a drum stick or "stab" the filler at the puddle hit the tungsten and foul it. get used to grinding your tungsten and get in the habit of stopping to regrind as soon ale. I usually don't suggest new students stab the filler at the beginning as they usually will constantly you foul the tungsten. Once students can add filler using the lay wire method, I usually suggest they learn to tap in filler, "stabbing" usually requires more eye hand coordination than most new tig students have at this point.

You also will want to practice feeding filler with your left hand ( assuming you are right handed). Get yourself a length of filler rod, and practice feeding it thru your hand while wearing your tig glove when you are watching tv to help develop the muscle memory for doing this. New students usually end up running 2 to 3" of bead, then they have to stop and reposition the filler. The idea is to gain the muscle memory so you don't have to do this. Really experienced tig welders can even grab new rods and continue without stopping.

Once you can run consistent beads the full 6" length of the plate, try overlapping the previous bead by 50%. Once you can consistently do these, you can move on to lap joints, followed by T joints, outside corners, and finally but joints in that order. On average a student usually only gets thru lap joints in the 48 hr class term. Don't get discouraged, this will take time and gets faster as you move along.

Then you go back to the beginning for horizontal joints and start the whole process all over again with beads on flat plate... Then the same thing for vertical followed by overhead. After all of this, you can move to thinner material and start all over again with say 1/16" and then finally start on round tube.

Note these drills while boring, are very critical to learning to do this right. I see a lot of people who want to stop and skip to chapter 20. Then they wonder why they constantly have issues. Problem is they never learned the basics.

One other thing. Because tig allows you the most control over the weld, it means that there are a lot of things you will have to manage all at once and keep the same to get good results. Best way to learn is to take a class so that someone can watch as you weld and pick up on many of these small changes that you are not aware of. There's only so much that can be done with picts. It's much easier to pick out a lot of this stuff if someone is watching you though. When you sit down and add up what it would cost you in gas, rod, electricity and materials, not to mention instruction, a class is usually stupid cheap. Around me a class averages about $10-15 per hour of class time. One other advantage, most institutions usually have much better equipment than the average student is equipped to start with. This helps remove any issues if the problems you are having are due to the skill of the student, or issues with the machine.

I'm sure I've left out a ton of things, but this should get us started for now. Good luck.

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For those that don't have a tig machine with a remote capability, or those who want to do DC tig using a DC stick welder, things are a bit different than what was listed above.


Now the only ways you have to control your heat, is by using some "advanced" techniques. You will control heat thru arc length ( distance the tungsten is from the work), travel speed, and how much filler you add and when to cool the puddle. Here filler size begins to matter. A bigger filler will chill the puddle more than a smaller one will, but bigger filler means you add more filler with each dip. You also have to have your amps pretty close to optimum. If anything I tend to err on the low side with amps if I can't use a pedal. You can then slow down to add more heat if needed or increase you arc length some more. Note there's only so much you can do with these methods, so getting close with your amps to start is important.




Since we are on this track, anyone with a DC capable stick machine can do basic scratch start tig. All you need is an air cooled tig torch with a gas valve, the regulator and hoses, an argon cylinder, a power block or tweeco connector to fit your machine, and the tig parts to fit the torch. Guys use these systems daily in the field, doing xray quality welds, so it isn't a huge handicap. It is harder to learn at the start however without a pedal. Rough guess would put all the parts less cylinder at maybe $250-300 new, less if you can pick up used stuff.



Note that you can often find really good deals on older dedicated tig machines, especially rebadged units. I've seen old Miller 320 and 330 AB/P's selling for $500-900 plus cylinder and I've seen the rebadged ones made for Airco go as low as $200 in working condition. Down side is these things are heavy (almost 900 lbs), huge ( size of a large refrigerator) and want a fair amount of power ( 125 amps 230v to run full out, 50-60 amps230v will get you 1/8").

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