Bath Condition of Electropolishing

http://anodizing-process.blogspot.co.id/2008/01/aluminum-anodizing.html
Electropolishing bath commonly are based on sulfuric and phosphoric acids in about 50 % by weight proportion and operate at about 54 to 105 oC for ferrous alloys, 85% phosphoric acid for copper at about 43 to 60 oC; and phosphoric acid with about 5 to 7% chromic anhydride (CrO3) at about 60 oC for brass.

DC electric on this process is needed and the current density of aluminum electropolishing range from 5 to 40 A/dm2, depending on the metal being finished, type of bath, and temperature. The time required usually is 2 to 7 min for current densities of 15 to 30 A/dm2 and temperature of 54 to 82 oC. For higher current density the process can be faster but be careful because if to higher current density can make aluminum surface broken, better use electric current density increase gradually, this arrange to make better result of aluminum anodizing.