Kevin has heard from some people who have just gotten a TIG welder and can’t get it to work. They can’t figure out what’s wrong – they often think the machine is bad. That makes this a good time to talk about some of the things that can go wrong.
One of the biggest mistakes first-time TIG welder owners make is getting the connectors for the torch and ground connected wrong. The connectors look the same and hook up the same, but they definitely are not the same. For instance, one might have a negative symbol on it, but that’s not necessarily for the ground, as you might think.
Kevin shows the Longevity ProMTS 200, for which the torch connects to the positive, and the ground to the negative, but other machines are the opposite. Kevin says you have to check the book for your welder – they don’t all handle connectors the same way – to make sure you are hooking up the torch and ground correctly.
Another one of the things that go wrong happens when a machine is not assembled correctly. With the AHP AlphaTIG 200 X and DX, there is a small plastic piece through which the torch cable needs to be threaded. The brass is hot electrically – that’s how the current gets to the torch. The gas also goes up through the middle of the hose. If you don’t put the black plastic sleeve on the torch cable, the brass is electrically hot when you’re welding, and that can be a good way to get shocked. Just hand tighten it – you don’t need a wrench.
Another thing people seem to have a problem with is getting the pulse to work. Kevin explains there are different settings using different knobs. There is the main amps or pulse peak. Then there is pulse amps, or pulse base, which sets the bottom of the pulse. A person he was helping had the knobs set the same, so there was no variation, even though pulse was on. You can turn the pulse base down just a little, or try turning it all way down so you can see the pulse. Play with it, and you will start to get the hang of it.
Next Kevin discusses something that is especially prone to going wrong when welding when it’s hot. Gloves alone are not adequate safety protection – you need sleeves of some kind. When you get sweaty and lean on the bench, a sculpture, a car, etc., you become part of the circuit and get “a little tingle.” If get between the ground and the current, you’re going to get a “tingle.” Even just wearing heat sleeves will insulate you from the work and prevent this safety hazard.
One of the biggest things that go wrong with TIG welders, especially for people just learning how to TIG weld, is sticking the tungsten. Inside the welder is a high frequency start board that allows you to start your arc clicking the trigger or depressing the foot petal while simply close to the work. On the board are contact points that either open and close or otherwise have a current arc across them to start the welder.
People who stick the tungsten to their work or even touching the filler rod to the tungsten on the work, not only weld everything together, they can burn up their machines. They also tend to get shocked right through their gloves. And, because the machine is still on, the high frequency points are saying, “The arc went out! I better start it again.” The welder then starts dumping current through the contact points and eventually burning up the points. After 10, 15 times, the welder can get harder to start, sometimes leading people to scratch the metal to get started. Kevin says you can adjust and clean the points, but most of all, you need to avoid sticking that tungsten to the metal. It’s one of the biggest killers of TIG welders.