The video starts with a mystery greeter asking Kevin what he’s doing as he peers inside an open AHP AlphaTIG 200X TIG welder with a flashlight. Some viewers are having trouble getting their TIG welders with high frequency start capabilities to start, and he thought it would help to show them how to fix the problem.
With the welder’s cover removed, Kevin shows the inside of the machine. He acknowledges that every welder is going to be a little different. Some machines don’t have points anymore at all; they’ve gone completely electronic.
Next Kevin shows the high frequency electronic board and contact points from above. When you push the welder’s trigger or step on its pedal, an arc crosses the two contact points as the arc appears at the end of the tungsten. The contact points have now done their job until you need them again or the machine senses that the arc is about to stop, whereupon the contact points come back into play again.
When the electricity jumps across the two contact points, they get burned a little – just like the points in old-style automotive ignition systems.
So if your TIG welder uses high frequency start and it’s getting harder to start – you have to get closer to the metal, or you sometimes even have to touch it to get it to start – the contact points have gotten dirty.
To fix it, Kevin takes a small square of emery paper and puts it into a pair of forceps. He reaches down and scrubs each contact, then blows the air to get the dust out.
Next he comes in with a feeler gauge to check the gap – check your owner’s manual to determine the right thickness for your machine. He is setting this one to 29 thousands, which is just a little tight.
Kevin reminds viewers that the contact points may be in different places on other machines. He says they are usually found in the front of the machines, sometimes in the front left corner right behind the control panel, but they’re not going to be in the back of the welder or below near the transformer. He says these are fixed but some actually move. Now Kevin is ready to go back to work.
(Don’t miss the extra fun at the end!)