"Gunner Asch" wrote in message
...
On Sat, 03 Sep 2005 20:42:01 GMT, Bruce L. Bergman
wrote:


His welding is another matter.

You heard, I see. Did his spare tire ever arrive? The guys in the
space station said that the trajectory had it heading for Oz...


Sigh..they found the tire. Its about 15 light years out and heading
for the Lesser Magallinic....

Blush. Not a mistake Ill make again.

Ill find new mistakes to make.

But..Im now welding aluminum...and the welds are holding...YAY!!!

Gunner

"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Gunner,
Are you Mig welding aluminum? If so I can give some useful hints. There
are a couple of things that will tell you if you are doing it right.

First, look at the end of the wire sticking out of the gun after welding.
Is the end a sharp point or a round ball? If it is a round ball, then you
are using short arc and aluminum should be welded in spray arc mode. Raise
your voltage a little at a time until you get spray arc.

Second, what does it sound like when you are welding? Does it sound like
eggs frying on a hot pan? Then you are short arc welding and you need to
raise the voltage. Spray arc transfer sounds like a spray paint gun being
used.

Third, what does your weld look like? Do you have lots of tiny sharp edged
ripples in the bead, or is the bead fairly large smooth ripples? If they
are sharp edged you are using short arc, and the voltage needs to be
increased.

Fourth, doe your welding produce a shower of sparks as you weld? If it does
then you are using short arc and the voltage needs to be raised. Aluminum
Mig welding should produce very few if any sparks. It not only should sound
like spray painting, the arc should look fan shaped and it should seem like
you are spraying the metal onto the surface.

Notice I kept mentioning the need to raise the arc voltage. That is because
most of the time I tell someone this they say "I tried a higher voltage and
it didn't work better" That's because they needed to raise it a LOT more
than their experience with steel would suggest. Note that as you raise the
arc voltage you must usually raise the wire speed quite a bit too, otherwise
it will burn back into the gun. When you make the transition from short arc
to spray arc though it is a wonderful thing, and I promise you'll know it
when you see, hear and experience it.

One of my greenhouse customers had a guy come in to weld thousands of
aluminum rolling benches. This was what the guy did for a living. I
watched him weld for a few minutes and told the customer he wasn't using
spray arc and the welds were not strong, and he could go faster. The
customer asked the guy to let me adjust his welding machine. He wasn't
really happy about that, he was getting paid piece work and any fooling
around cost him money, as would changes that slowed him down. However he
let me make the changes partly because I had already gotten him a really
good deal on an electronic helmet. In the end the customer was very happy
because the new benches were holding together much better than the previous
ones. The welder was happy too. It turned out that my changes made the
welding a little more difficult to do. However it cut the actual welding
time almost in half, and he was getting paid by the piece not the hour!

Please let me know how you make out.

Gary H. Lucas