CAMCOMPCO wrote:

Not to be a dufus here, but just what is grinding "axially", I grind my
tig electrodes and would hate to think that the trouble I am having
welding Aluminum is because I am grinding my electrodes wrong.

Thanks

John

The grinding marks need to run along the axis of the tungsten rod,
a.k.a. along the length.

Aluminum is tricky for sure. According to most references you're
supposed to ball the end of the tungsten when welding aluminum. You're
also supposed to use pure tungsten or the newer Lanthenated for
aluminum.

Various sources indicate you should grind it leaving a flat at the tip
and then run it on DCRP (I think) on a scrap of copper to ball the end.
Other sources say just point it like you would for steel and run it hot
on a scrap for a few seconds to ball the end.

The aluminum alloy and it's cleanliness make a huge difference in the
results. The AC balance control on the square wave TIG machines helps a
lot in overcoming surface oxide issues. The other thing that is a bit
counterintuitive is that you need more current on aluminum due to it's
thermal conductivity. You have to basically hit it hard and get the weld
done before too much heat spreads outside the weld area and turns the
whole thing into a puddle.

I'm certainly no welding expert (Ernie on sci.engr.joining.welding is),
but the things that I've welded (steel and aluminum, mostly TIG) have
all held together.

Pete C.