To make electropolishing of aluminum need of some chemicals on bath. Chemical solution on electropolishing bath can be different of every process, its depend on the purpose of anodizing process. If just make the surface stand to corrode, this can be proceed more easier because the result of andizing process may not bright but already anodized. On this purpose the important of oxide film on the aluminum surface must be thick and strong.
The color of anodizing product can be just transparent or just semi dull white color. The most common used in electropolishing bath are based on sulfuric and phosphoric acids in about 50/50 weight proportion 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.