TIG welder setup Basics - Getting the most out of AC settings
Besides pulse, one of the most important adjustable features on a welder like the Everlast PowerTig series, or the Miller Dynasty series, is the adjustability of the AC frequency, and the AC balance. Both play their part in getting the most out of a AC arc while TIG welding.
AC frequency has been covered before. However, many people fail to realize just how important this feature is, especially if they have never used an inverter with features like this before. Standard transformer welders don’t have any choice but to operate on the same frequency that is supplied to the welding machine through its primary transformer. In the US, that is 60 hertz. Though that is adequate for many welds made in aluminum, it is far from ideal. A more ideal setting would be twice that at 120Hz. This level focuses the arc cone, and improves arc stability. Inverters excel in this because the frequency is generated by electronic components rather than the input power line.
AC balance gives a choice between penetration, and cleaning. Older transformer TIG welders have pretty much the input power line balance of 50/50 ratio between Electrode Negative and Electrode Positive. This offers typically more “cleaning” than is required to break up the oxide layer on aluminum. And it also overheats the tungsten, creating a molten ball on the tip of the tungsten, destabilizing the arc. A sharp tip can be maintained while increasing the penetration of the welder with just a 20-30 percent setting of Electrode Positive. Again, inverters open up the possibilities here by offering adjustable balances. Even when times call for it, inverters like the Everlast PowerTig series can operate at nearly 90% or more of full electrode positive, creating huge amounts of cleaning. Though that is unusual, and a little harsh to weld with, it is nice to know you have that adjustability at your finger tips.