[RayJ]

I'm new to annodizing. I need to Hard coat(type 3) tuned aluminum exhaust pipes for my rc cars. The pipes are typically 8 inches long, 1.5 inches in diameter. The pipes are approx. .050" thick of work hardened 1100 aluminum.

I have a 30amp 12 volt continuous unregulated power supply. Can someone recommend a rectifier? Or do I need one?

I'm very curious about Oxalic Acid hard annodizing. Some of the articles I've read by the Japanese use a 3% Oxalic acid concentration(no sulfuric acid). They are using 40volts, and 15-20amps per square foot for 40 to 60 mins. They are also able to hard annodize at 70 to 90 degrees F with agitation.

I'm tempted to go this route since it would elimante the need of an expensive cooling system. Any suggestions would be greatly appreciated.