aluminum to black

[ISAMEMON]

so here is a strange question.

I have some small bits of aluminum that I would like black in color. yes I can paint the stuff, but........
so in a discussion with a friend, an old farmer, he said to spray it wth easy off oven cleaner and just let it sit on. He said it would turn it black, and is hard to get off. not a shiny finish but a dull black

well I dont have any oven off right now,
but was wondering , any of you ever heard of this, any of you got a can off easy off that you want to spray on a scrap of aluminum and see what happens ?

Otherwise, I ll try, in a few days .

[20774]

Yes, Easy-Off oven cleaner will turn the aluminum a dull, gray color, but I don't know about black-black, though. I believe the component in it is muriatic acid. Some mag wheel cleaners also have this acid in it.

I suppose that with repeat application the part will get blacker and blacker, but I wonder if those repeated applications are also damaging the part??

[kantuckid]

Research "painting aluminum" or "aluminum primers" as it's common to paint it and certain primers are best.

[ISAMEMON]

Research "painting aluminum" or "aluminum primers" as it's common to paint it and certain primers are best.

very true, and I have painted tons of aluminum and powedercoat, but like I originally said, I only have a few parts, the farmer said it wont scratch off, just thoguth it was interesting to look into.

you never know what an old farmer will tell you

[40401]

I just checked in the kitchen cupboard. The active ingredient in Easy Off is sodium hydroxide, an incredbly corrosive base. We used to use it in dip tanks for cleaning cast iron engine parts. One time a kid put an aluminum timing cover in the tank and the next morning the cover was gone; disolved in the solution.

I'm not sure it will turn aluminum black but it will pit the finish in a very short time. I've seen it turn shiny aluminum dull grey in a matter of seconds.

[Pauls1150]

I've milled custom heat sinks for integrated circuits, and being in low-airflow locations, they had to be black for thermal conduction.
We sent them to a local plating shop for Hard Black Anodization - not just black anodized: it's necessary to additionally specify the "Hard" part, or it will scratch easily.
So if you've got the dollars, that's another way.

[Stan_R80/7]

Birchwood Casey makes an aluminum black - primarily intended for sporting goods such as rifles, etc. Here is the MSDS:

http://sport.birchwoodcasey.com/file...um%20Black.pdf

It uses several acids to do the job - so gloves and eye protection are needed. Like most metal finishing, all the work is in the preparation. As mentioned previously, sodium hydroxide dissolves aluminum and will strip anodizing (including an acid based finish such as aluminum black) very quickly. Good Luck!

[lmo1131]

from the MSDS

FIRST AID MEASURES

EYE CONTACT: Flush immediately with clean water. Continue for at least 15 minutes. Seek immediate medical attention.

SKIN CONTACT: Remove contaminated clothing to avoid prolonged contact. Wash affected areas with water. Call Poison
Control Center IMMEDIATELY (866-291-7152) for further instructions.

INGESTION: Do not induce vomiting - call poison control center IMMEDIATELY (866-291-7152) for further instructions.

INHALATION: Remove from exposure. Seek medical attention if necessary if breathing is difficult.

Nice stuff!