welding technique for clusters

On Mar 24, 2:02*am, Bob Hoover wrote:
On Mar 23, 8:14*am, wrote:

Without seeing it I would have guessed a contaminant on your filler
rod, but if it's happening ahead of the pool it may be something on
the tubing, such as some sort of residue from the zinc.

-Bob

I'm leaning toward that myself. When the tubes came out of the acid, I
rinsed them in clean tap water and then let them air-dry. I actually
watched them rust in a period of 5 minutes. Once the tubes were dry, I
shoe-shined them with a Scotchbrite pad. They looked nice and shiny,
but I didn't do any further cleaning. I also didn't clean the filler
rod. Its copper-coated, but that doesn't seem to be doing it, or I
would have the problem all of the time.

Next time I'll try degreasing them in Simple Green (my prefered
weapon), rinsing, etching, and rinsing again. Then air dry, polish
with 220 (cause that what 'ah got), solvent wipe with acetone, and
then give them the tan-glove treatment. Finch's book also recommends
solvent-wiping the rod. I'll try that too.

In looking at some of my work from last Sat. there are sections of the
bead that would be acceptable if the feed-rate were more even.
Overall, they look a LOT better than my first atempt. I don't have the
heart to whack the hell out of any of them yet. But I'll get there.

The first trial-project will be a chasis for a kinetic sculpture
vehicle. That would be a human-powered, art/vehicle that is capable of
traversing roads, trails, mud, sand, AND lakes while looking cool. I'm
thinking something like a Warren-truss for the basic structure.
Imagine if you chopped the back end off a Breezy and stuck three bike
wheels on it. On top of that goes the sculpture of your choice. If
that structure survives what I'm going to put it through without
cracking, I should be well on my way as a weldor.

Harry