guys
every once in a while i get a very erratic arc when running on a/c and welding thick aluminum. its about to drive me crazy.
running the balance at 7, amps at 300, 75/25 argon helium anywhere from 15-35cfh. i have tried cleaning the ground area, clamping ground directly to the part, two different bottles of gas, etc... i am at a loss.
one day everything could be fine, and the next it drives me crazy.
the arc kind of wanders all over the place and it even sounds different then when it runs good. and the paareacne of the bead is really flat. when its acting up i can not get a good apperaing bead at all.
i have searched the internet and found something called "high frequency leakage",.....
the article stated, "if you have a part(s) of your torch/lead that is/are damaged, the HF will leak and thus reduce the amount that is available at the arc to properly stabilize it"..

my torch and 25ft cables are 4 1/2 years old. and being 25ft in length, they are wrapped around the machine handles.
have any of you had the "high frequency leakage" as stated above ? the article also went on to suggest running a bead with the lights in the shop turned off and having a coworker look for for arcing anywhere throughout the cables..

any help would be greatly appreciated on this subject.

after the holidays when i get back to work i am going to order a new set of cables and torch, probably 10ft in length, just to get them out of the equation.