TIG WELDING ALUMINUM QUESTION:
We have an "old as balls" miller tig at work that works just fine.
So after I set the current to AC, what would I want the "power" to be at(I don't know the correct term, it's the dial that apparently increases the heat the further you turn it up) for 1/8 - 1/4 inch thick aluminum?
I would say set the amperage to around 250 and use the foot pedal to control amperage.
If your dial reads 0-100 instead of amps, you will have to guess a percentage of the total for example if it is a 300 amp machine, you would set the dial at about 80 percent.
And then there are those old dinosaurs that have several ranges.
They are still good machines but there is always a zone where you are not hot enough on the low but too hot on the high. You just have to feel it out by farting around with it.
That brings me to this little trick: If you have an old Tig welding machine and it seems to not be consistent on amperage, check out the foot pedal before you decide the machine is a piece of junk.
I have seen a bunch of times where all that was needed was a new resistor coil in the foot pedal and the machine welded good as new.
New Tig welding machines that have features like A/C balance are great. But If you have an old Tig welding machine like a Miller 330 abp, or a Syncrowave 300,
They literally do not make them like that anymore. Copper was cheap when those things were made and they put plenty of it in the machine.
For the basic settings for tig welding aluminum with one of these old tig welding machines:
set high freq to continuous, amperage and contactor switch to remote, use a 1/8 electrode, a # 7 cup with 13-15 cfh on the argon. If you can, get a cylinder of 50-50 argon/helium and things will go much, much better.
Thought for the day...
Old as balls Miller tig welders , like senior citizens, while slow and dangerous behind the wheel, can still serve a purpose. (loosely quoted from Jim Carrey "Dumb and Dumber")