wrote in message
oups.com...
I believe the Aluminum Manufacturers Association or whatever the
correct title recommends constant current for MIG welding aluminum.
Which kind of makes sense to me. You need constant voltage for Short
Arc, but I would think Constant Current would work better for Spray.
Do you have any experience or knowledge on this?

I tried MIG welding aluminum and did not have much luck. Maybe it is
time to try again. For trying to find out the right settings at home,
what thickness of aluminum would you recommend for a beginner to try.

Dan

Dan,
You can use either one. A couple of years ago the one customer wanted a mig
welder for repairing his aluminum benches. He bought a push feed Lincoln,
but it really sucked for aluminum. It also wasn't portable enough.
Greenhouses cover acres and he wanted to be able to go to the problem. He
had a gas powered Miller stick (constant current) welder too. I bought him
a Miller Mig gun with the 1 lb spool in the handle. Both dealers I got
prices from told me it wouldn't work. However I had done my homework and
the control I bought with the gun had a switch for constant current or
constant voltage. So it worked okay. Okay because in order to Mig weld
with constant current you have to vary the speed of the wire feed to
maintain a constant arc length. With constant voltage though the arc length
is automatically a function of the voltage drop across the arc. You just
run the wire at a constant speed and you are done. The constant current gun
was harder to start as well. When you pulled the trigger the wire would
come out slowly until the wire touched the metal and the arc was
established. It didn't burn the wire off quickly like constant voltage
does, because the current can't shoot way up. So the gun kind of kicks when
the wire stubs the metal. So overall constant voltage is preferred but in a
pinch constant current works.

Gary H. Lucas