On 20 Oct 2005 15:30:16 -0700, "
wrote:

Hello Wayne,

Thanks for the suggestions. I really am using 100% copper (Alloy 110).

I already figured out the insulating bit when I made the hinges. When I
was welding the hinges on the metal table, I couldn't get a puddle.
When I put the hinge in a little cave of fire bricks, I was able to get
a puddle.

I can try welding two 1' sections of the bar. However, considering that
copper seems to just suck up the heat, I'm not sure it would be a good
test considering that I'll actually be joining a 4' length to a 6'
length.

I like the end cap idea, but not sure how I would fabricate those. I
can always screw on gussetts to the bottom since there will be a copper
panel on the lower portion of the gate that would hide the gussets.
However, gussets on top would be ugly.

When/if I finish this, is this the kind of thing people would like to
see in the drop box?
I'm no expert, but there was once a time when I had to weld copper. It
was 3/4" thick, 4" wide, and a little over 2 feet long. No way could I
weld it with a 300 amp tig torch. I called the welder who usually did
our fancy stuff and he said a good pre-heat would do it. So, using
fire bricks I was able to fill in the 1/2" deep 1" wide goof in the
part using copper wire as filler. It seems to me that after heating
the bar I covered it with fire brick. I for rested my hand on it while
welding. Even with the preheat I think it took at least 250 amps. And
I may have been using helium. We used helium for some aluminum jobs
and ran the torch DC. The metal had to be real clean but boy, could
you really lay in the rod.
Eric