Anodization takes the top layer of a metal and makes it very microscopically porous. These pores are small enough to hold other chemicals such as dyes. These pores are then typically sealed either by using a chemical sealer or boiling water to prevent the dye from escaping again. By using anodization, a really kick ass color effects can be added to metals (typically Aluminum).
Aluminum anodization occurs in a bath of 20% sulfuric acid. This can and will burn your skin. In addition, a small amount of vapors are produce that don't smell very nice. Anodizing should be done in a well ventilated area with nitrile gloves. Also, having some baking soda around to neutralize any spilled acid is super duper handy.
Procedures tried so far
- 1 hr. in 20% H2SO4 bath, rinse in cold water, 2 min. dip in RIT green dye bath @ boiling point, 5 min. boiling to seal
- 1 hr. in 20% H2SO4 bath, rinse in cold water, 3 min. dip in RIT green dye bath @ boiling point, 5 min. boiling to seal.
The second attempt had better color uniformity, but there was still a lot of dye on the surface post sealing that did not come off in the rinse. Perhaps a longer sealing time should be attempted?