Black dye

[gbtweedy]

I just mixed up some black dye last night and gave it a test run. I always check all of my parameters temp, volts, amps and record the data. What I was shooting for was 1 mil thickness at 6ASF. Well after ~15 min in the dye I pulled out the part and I thought it was the nicest looking thing I have ever seen in my life. When I sealed it I got a lot of dye bleeding out and it was a reddish-brown color.

Well I looked everthing over and found out that I am retarded and mis-calculated the surface area and when I plugged in the correct numbers in I found that it would have only produced an anodize layer of ~.8mils

So my question is, given my situation does it appear that my problem was a result of the thinner anodize layer or is there something else that I may be missing?

[acidrain]

I'd say yes, the thinner layer does not give a nice deep black... go for a ful 1 mil and you will see a difference.

[archimedes]

Greetings,

hummmmm . . . . . .
I would not make such a conclusion so quickly about your brownish black
dye result.
Acidrain is right but maybe there is something else here . . . . .
Certainly pore structure is critical in the dying process, but
how does a thickness of .8 make any difference from a thickness of
.2 so far as "dye leeching out" . . . . . . and resulting brownish tint ?
Researching many archive posts, I must say that there could be a couple of
issues in cohorts to negatively affect your final result.

1. Black dye PH is important. --- check archived threads to capture this
significance. MD,Neomoses will produce
some good analysis.
2. Substrate category ---- 6061 vs 7075 vs 2024 vs . . . . on & on but it
is important. 2024 & 6061 in same tank, same
LCD parms --- very different in black "depth"
after a successful process.
3. Check all categories of your process --- something is amiss. A
parameter or set of parameters is not building a bridge successfully to
your next process.

This seems like a very nice return for the investigative effort. I wouldn't
hesitate to review and step through this particular Ano run. The ability
to intuitively understand the interelationships of all the variables in the anodizing process is in this type of circumstance.
archi