Welding Tips and Tricks

Hi new to TIG ..read very new, and I read as follows
> The reverse polarity half of the A/C arc does an outstanding job of cleaning off most of this oxide ahead of the weld! How does that work? Well the reverse half of the alternating current acts like a sandblasting operation that breaks down the oxides.
Then on another site I read
>
When aluminum welding, the positive (+) portion of the AC welding
amperage cleans the oxides from the aluminum surface. The negative
(-) portion delivers more heat input, increasing penetration
level.Appears to be direct opposite info and certianly confusing to a newbie ?

You then add to this that on some wleders the clockwise direction increases + percent of balance and on others lincoln for example clockwise increases penetration (Neg)
But then that depend if Positive is the cleaning part or negative is ?
In short HELP as damn confused here ?
Thanks Heaps

Hi Faster, if i read ya correctly I think i know where there cunfusion lies.

RE: DC current -

Back in the day we refered to polarity as " DC staight " and " DC reverse "

Nowadays it is refered to as DCEN ( DC Electrode Negative ) and DCEP ( DC Electrode positive )

........................ They are the SAME thing, just different terminology! ...................................
DC Straight = DCEN, ........................... DC Reverse = DCEP ...................................
(DC -) ........................................................(DC +) ..............................


Where it relates to A/C current The newer terminolgy blends seamlessly and is more understandable,
A basic A/C sine wave goes from approx. 50% electrode negative, and swings up to 50% Electrode positive and continues thus.
The positive portion is where there current travels FROM the work piece TO the torch - and is the cleaning portion of the wave. During the Electrode negative part of the wave, the current (heat) is going into the work piece. With a square wave machine he ac wave passes thru the "zero" point faster, providing a more instantaneous if you will, transistion between the two cycles. A/C balance alows you to manipulate
how long, during each cycle, the current stays on either positive or negative. As far as which way to turn the balance control is simply however the manufacturer designed the control to operate, but it does the same thing. Either more cleaning as you turn clockwise, or more as you go counter CW. Doesn't matter as long as ya understand the principal. Hope that helps.