On 2 Jun 2005 08:43:13 -0700, wrote:


What you need to do is find the process description for decorative
anodizing.

Last night after posting, I found this site, which is hands down the
best descriptive site I've found to date:

http://www.focuser.com/atm/anodize/anodize99.html


IIRC, we tried to keep the concentration of acid
down below 10%, if it got above that, the oxide cells started getting
soft and flimsy and didn't soak up the dye. The temperature had to be
controlled, too, too hot and the same thing happened. We tried to keep
it as cool as we could, usually below 80 degrees, when the chillers or
circulation pumps went down, we were out of business.

I may be experiencing both problems, too high an acid concentration,
as well as excessive heat.

The power supply was a constant current one, topped out
at 10000 amps. A full rack of extrusions usually ran about 6000 amps
if the acid concentration was correct. I have no idea what the voltage
ran, current was what was specified in the process manual, so much per
square foot for each different process.

I wonder if using my Miller 180SD welder in DC stick mode as a
constant current power source would violate any warranties?

One other question, since I don't know the pedigree of the material I
made that threaded adapter out of, what if it wasn't aluminum, but
actually magnesium? (The two materials are difficult to tell apart,
yes?)




Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction, Testing, and Coating site)

Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent.
Calvin Coolidge