Common TIG Welding Issues, Hard-Starting - Part 8

Common TIG welding issues part 8. TIG: Hard startingAC TIG welding on aluminum presents several challenges when starting an arc. As mentioned previously, oxidation, even shiny oxidation can serve as an impediment to arc initiation. AC TIG arc starting difficulty is more commonly reported than issues with DC arc starting in part due to the oxidation factor. But one of the causes that is often missed is the maladjustment of welding parameters. Not only from poorly selected amps, but also from incorrectly setting AC balance and frequency level. Let’s be clear here. Just because a welder has a lot of bells and whistles and capacity for adjustment it does not mean that it will weld well at any combination of them. Having adjustments means that the unit can do some really special things for you if you know what you are doing. One of these adjustments is the AC balance. AC balance controls penetration and cleaning. Cleaning is a function of electrode positive. Very little is actually needed, with only about 30% Electrode positive, and 70% electrode negative being needed for most jobs. Settings higher than that up to 50% can improve cleaning on really dirty metal. However, anything over that is often wasted and unnecessary. And excessive Electrode positive during arc starting will result in an arc that will wander and dance around during and after arc starting. This can be a problem cause for rapid electrode consumption and contamination as well. AC frequency can make for hard arc starting if it is too low as the arc will tend to wander and flutter around during and after the start as well due to the longer time spent in electrode positive before switching to electrode negative during one AC cycle.Everlast Power Equipment, Your Complete TIG Welding Resource.Learn more on our welding forum