I finally got around to trying some anodize dyes. Dyeing is an extra step in between anodizing and sealing.
First, I did a normal anodization to obtain a 0.001 inch thick coating. Conditions to achieve this are discussed in the March 3, 2012 posting to this blog.

I did my dyeing of these small samples in a 16 ounce mini crockpot, using 8 ounces of diluted dye. This crockpot did not have a power control, so I ran it with a variac in order to maintain the solution at 140F.

The dye solution is 8 ounces of distilled water and 1/8 ounce (3.7 ml) of dye concentrate. To measure the dye concentrate with some accuracy, I used a transfer pipette. It is graduated, and can pick up 1 ml at a time.

Sealing is the usual procedure of boiling in distilled water. I did not observe dye leaching into the sealing water.

Across the bottom of this picture are 4 dyed samples: Black HBL, Bronze, Copper BF, and Gold S. These are from Caswell. Also in the picture for comparison are two scrap pieces of 360 brass.

The Gold dye comes out the closest to brass, but my samples were unevenly colored.
The Copper dye is something of a strange color, best described as “pumpkin”.
The Bronze dye is quite dark, like a piece of sculpture that has been given a patina.
The Black sample is quite satisfactory. This dye is more expensive than the others.

To get a satisfactory brass color, I will try to mix some of the dyes. I intend to use such a mixture in order to make “bimetal” reels.