TIG expert Wyatt “Mr. TIG” Swaim and Kevin sit down to talk about the fundamentals of TIG welding …. From the time you open the box of your TIG welding machine, what can you do with it? In this how-to video, Wyatt and Kevin are working with an AC/DC welder. Kevin says he mostly uses DC, for anything from small sculptures you can hold in your hand to a 16-foot tall tree. He welds a lot with TIG, “stick” (arc welding), and MIG, and he is always interested in learning more about the TIG. Wyatt introduces the 200-amp inverter power supply they are using, and offers a good rule of thumb: for every amp of power, you can weld one thousands thickness of metal. If your machine is DC only, you’re able to weld 4130 chrome moly, steel, stainless steel, inconel, titanium – all kinds of metals – but you’re going to need AC to weld aluminum and magnesium. This welder is an AC/DC machines.
What about gas? Wyatt recommends 100% argon, not a CO2 blend or other mix, which you can get from your local welding supplier. Argon is all-purpose and it stabilizes your arc. If you start blending helium and other special gasses, you’re going to have instability but probably you won’t know why. Argon transfers electricity; helium does not. Helium is an insulator, so the arc is trying to punch through the helium, and the arc will wander.
Next Wyatt addresses TIG torches. First he shows a large torch he calls “the club.” It may be helpful for heavy-duty welding, but most TIG welding is fine welding, so he is going to use a smaller set up called a “gas lens.” The torch is smaller, shorter and easier to work with.
Then Wyatt and Kevin discuss when to use a foot or hand control. Kevin uses the foot pedal when he’s sitting at his workbench, but likes the hand control when he is working on a sculpture in an awkward position. Wyatt says he uses a foot control 90% of the time. He shows a foot pedal that offers variable action. You can also attach an on/off switch to any torch, which allows you to start the arc either when you click on it and work while you hold it (2T) or start when you click and release, then end when you click again (4T). The on/off switch, however, doesn’t give you the variable control that the foot pedal does. That lets you let the amperage increase slowly as you depress the pedal, so you can better control when the puddle appears, etc.
Next Wyatt explains that you need to be able to see the puddle 10 – 15 inches away from the work. If you can’t see, you’ll have all sorts of problems, including contaminating the tungsten. Most helmets have variable shades that go from 9 to 13. Which you select has to do in large part with the sensitivity of your own eyes, but if you want a nominal setting, you probably want to start with 10, which is the only choice some helmets offer. If you’re doing very intricate welding and using low amps, it’s often hard to see the puddle, so you may want to turn it down to 9. If, at the end of the day, your eyes feel fine, you’ll know that works for you. If you’re using high amps to weld, say, heavy aluminum, however, you may want to move the dial up. Most of Wyatt’s TIG welding, which involves aircraft, aerospace and Indy cars, is under 125 amps, so he can use a number 10 shade in his welding helmet all day long. If he is welding aluminum, however, it has a few more emissions and a glare that may encourage him to increase the shade level as high as 11. This is why the variable helmets are helpful. There also are simpler helmets that you just put a fixed lens into. Just be careful not to use a 5, 6 or 7 lens, which are for oxygen-acetylene gas welding, or your eyes are going to hurt at the end of the day. Kevin then asks whether auto-darkening or fixed tint lens offer any difference in visibility. Wyatt says that, although the helmets have gotten very good, he feels that a glass, fixed tint lens is a lot clearer than variable shade plastic lenses. So if he is doing micro welding at 2 or 3 amps, he needs the clarity. He also needs reading glasses, which you can get at any drugstore. Kevin shows the “cheater” lens that he puts inside his helmet, because he has trouble keeping the reading glasses on his nose. The cheater lenses come in all the same powers as reading glasses, but once you remove your helmet, you aren’t able to see as well as if you use the regular glasses. Wyatt show how the helmet Kevin is using has the lens shade control on the outside, which makes it easy to change the shade level on the fly (the control is inside Wyatt’s cool helmet).
Other safety gear worth using to protect against the ultraviolet rays emitted by the TIG welder include welding sleeves, which are cooler and easier to use than a welding jacket, and thin leather gloves, which are better for TIG welding. You definitely want to prevent “sunburn” on the arms and the V of the neck. Kevin likes to use a leather bib to ward off ultraviolet at the neckline. To contrast what you use with TIG welding, Kevin shows MIG gloves, which are much heavier and more spark- and arc-resistant – you don’t need the kind of control and feel that you need for TIG, when you have to hold your torch, your filler rod and feel your controls. You can also easily pick up your filler rod when you drop it. So if you’re TIG welding, make sure you get some TIG gloves.
Next Wyatt and Kevin discusses the tungsten and torch set up. Wyatt shows a couple of options. The first allows you to use a full-length, 7-inch tungsten. As you contaminate or grind it, it’ll get shorter, but when it’s full-length, it’s hard getting into some of the tight places. There are also all kinds of cups you can get. The argon setting is critical to your torch set up. The orifice of the cup he is using has about a 5 millimeter opening. If you turn your argon gas too high, you get turbulence, which negatively affects your weld. More gas is not necessarily better. Wyatt explains that you have to adjust your gas flow setting to match your cup size because it creates a venturi effect. So, for instance, this cup, because of the size of its opening, only handles about 10 -15 CFH (cubic feet per hour). So if he sets your tungsten to a normal, 1/4″ stick out, he’d set his flow for 12 CFH, although this is a pretty unforgiving set up. If you turn the gas flow up to 20, as soon as the argon gets to the end of the tungsten, it creates turbulence. Kevin says he likes a shorter stick out, because he gets less turbulence and the tungsten lasts a little longer. He also can turn the gas down and save on cost a bit. Wyatt says he doesn’t like to set the tungsten flush to the edge of the cup because that makes the arc too hard to see and ages the cup more quickly. Kevin points out that it’s also harder to get the tungsten out if it’s too far inside the cup. Wyatt says you can also use a 1/8″ stick out and turn your gas down to 8 or 9 CFH. For the all-purpose, very forgiving torch set up, Wyatt prefers a gas lens. Kevin says that they are huge. A gas lens has a series of screens,that shoots the gas out very gently in a column, giving you great gas coverage. You can then also run your tungsten out much farther, which helps in compound angles and other tight spots.
Wyatt likes a lightweight, small torch, which fits his hands better. Fortunately, you can put any type of torch on any machine. Kevin asks if you can get some of these parts where you bought your welder, and Wyatt says sometimes, but they he can help through his company, TIGDepot.net. He points out that it’s good to have options.
Next Wyatt discusses tungstens. There are about 10 or 15 different types of tungstens, which makes them very confusing. Kevin prefers the E3, with the purple head, and now uses it exclusively. It seems to work best for him in every situation. Whether he’s welding steel, stainless, aluminum, copper, he doesn’t have to keep changing tungstens. For many years, with tranformer welders, two basic tungstens were recommended: red, or thoriated, or green, which you use for aluminum. When inverter welders came along, green didn’t perform very well. So all sorts of new rare earth tungstens became popular, along with warnings about 2% thoriated tungstens being radioactive. Wyatt said the overhead lights probably emit more radioactivity than the tungsten, but the real issue is the grinding – just be sure you aren’t breathing the dust. Wyatt still prefers 2% thoriated tungstens with the inverters because he likes to weld super thin materials. Only when you get down to 5 amps and below do you ever see a huge difference between tungstens. Wyatt then shows some different types of tungstens, included a lanthanated tungsten, a ceriated tungsten, an E3, but Swain needs the 2% thoriated for low amperage TIG welding. It won’t go away. He rarely uses a pure (green) tungsten anymore, and certainly not with an inverter machine, because gives an unstable arc. You’re best off with something all-purpose. This concludes the set up of a TIG welder.
To ask questions of Wyatt and Kevin and visit with other artists and welders, visit Weld.com’s Weekend Warrior forum.