[RonLyke]

Dumb newbie question:

When welding aluminum AC, is the torch connected to positive or negative? I know the polarity alternates, but with AC balance changes, I would think it would matter.

Thanks.

[MosquitoMoto]

Hey Ron.

Torch is connected to negative.


Kym

[RonLyke]

Thanks, Kym

[MotoEngineering]

HI! for TIG welding aluminium you set your machine to AC . The TIG torch connection is the same connection as it would be for Steel which is DCEN (electrode negative) or the negative connection on your welder. You always use the same connection for TIG on the welder, you just change the AC/DC switch on the welder when doing Aluminium then just switch back to DC for steel. The AC BALANCE you referred to is when you are on AC and welding Aluminium it changes the sine wave to give you more or less AC +. To explain that electrons flow from - to + so if you have LESS AC+ TIME ON then more heat goes from torch to workpiece which is good for penetration and good for your Tungsten electrode. MORE AC+ TIME ON say 30% or more gives you more cleaning action and is good for thin sheet, you can combine this with pulse to make life easy on thin Aluminium sheet, but your electrode will ball up more. So to recap AC for Aluminium, DC steels and leave the TIG Torch where it normally is DCEN electrode negative. Low AC+ balance say less than 20% on time for good penetration and High Balance say 30% for good cleaning and thin Aluminium sheet. I hope this make sense feel free to ask for an explanation on any of it.

[Rick_H]

What welder are you using?

[RonLyke]

Motoenginerring---Thanks for the explanation. It seems clear now.

Rick---I have a Lincoln Square Wave TIG 200, new just a few days ago. I've been pretty busy, so I only have a few minutes on the machine. I'm new to welding, so I will spent running beads on thin steel for a while.

I appreciate all the help. I've been watching a lot of videos, especially Jody's and those from Chucky2009. Jody makes it look pretty easy!

Ron