Re: [OT]Coloring Metals

In a message dated 01/28/2000 5:43:57 PM Hawaiian Standard Time,
MIADsgns@... writes:

<< From: MIADsgns@...

In a message dated 1/28/00 7:27:34 PM SA Eastern Standard Time,
scalione@... writes:

<< >

> Peter
>
> BTW They also have gun blue, and a solution for aluminum. These are not
> paints. Anodizing of aluminum is not that difficult. Is that what you

want? >>
Yes Peter, it is basically waht I want, any thoughts on anodizing at home?

Thanks to everyone else who responded and sent me reference info.

Mario >>
Mario,

These are methods that have and still do work for me. Be careful of
children and pets around chemicals. Try these methods out at your own risk.
Get more detailed information off the net. There are many sites with detailed
instructions and more specific solution formulations. I will briefly describe
the procedure below to show how relatively simple it is. Again, do not
attempt unless you know the procedure is safe. Kids, Don't try this at home.

"I have had the best luck with the oxalic acid method. I read it in the
MAP book about electro plating. They dissolve a small amount (I can't recall
if it was two or three tablespoons But I have found it non-critical) of
oxalic acid in a quart of warm water. Stir until dissolved. Hang two of your
parts to be anodized in the glass or plastic tank. I use old tupper ware.
These parts need to be clean. If possible, just a few minutes after washing
off the machining oil is best. They also talk about acid etching parts
exposed to air for a longer time. Apply 24 volts AC, 40 VA, with a small wall
type plug in transformer. I get mine at ADI, the burglar alarm people for
$16. I use this set up for most all my small parts but if your parts are very
large, then a larger power source or a longer time may be required.

The parts, hung from aluminum wire, will bubble quite a bit for the first
ten minutes. As time goes by, the bubbling will diminish. The surface of the
part is becoming nonconductive. After about 25 to 30 minutes, take out the
parts and place in a small pyrex cookware with the dye of your choice. They
claim Rit dye works but I have never been able to make it work. India ink or
any of the commercial dyes work well. I've even used ink pad ink and magic
marker.

Once either colored or immersed in the dye, the solution is slowly
brought to a boil. This seals the pigmentation into the pores of the anodize
film. I think the theory is: the pigment particles need to be small enough to
lodge in the porous surface of the unsealed film. Once the part is boiled,
the pores close up, capturing the pigment. The film is easy to make, it's
making the color, texture and sheen correct that can take a lot of
experimenting.

I get my aluminum wire from the local welding supply. Get a small spool
of aluminum MIG wire. You could also get a small package of aluminum welding
rod. You must discard the hanging wires after every part as the portion
immersed gets a nonconductive film.

There are some DC type methods that are supposed to give better results.
You may want to try those.


Name Should be withheld

Peter