Hard anodizing is acheived by weakening the acid bath.
4 parts distilled water to 2 parts battery acid (SG 1.26 - approx 33% acid).
12-24 volts
0.1 - 0.15 amps/sq in area
Anodize for approx 60 mins for a good thickness and maximum wear resistance. The film forms at the rate of 0.10 mil per 2-3 minutes.
As we said before, hard anodizing isn't generally dyed, so we don't have any experience in how it will look. Try some sample pieces and experiment a little. You might also want to download our instructions on the anodizing page at
http://www.caswellplating.com/kits/aluminum.htm