Birchwood Casey Aluminum Black

[zahc]

I make lots of aluminum small parts and I set up to anodize a while ago. It's a pretty reliable process but unless you leave an anodizing setup all the time it's not worth setting up for 1-off parts. Then I learned about aluminum black product. Has anyone used it and what exactly is it like compared to anodizing or painting?

[Hawkmoon]

Not like anodizing. Much more like painting.

I've only used it once, many years ago. I don't recall details, but I was not very happy with the results.

[AJ Dual]

It's good for darkening up small dings and gouges in items that are otherwise anodized dark gray or black.

Even with padding on the pliers, I messed up a suppressor cap something fierce when it got seized up, and was able to darken the gouges so it looks decent from a distance of a foot or more.

Does it pass close inspection? No way, but it's a vast improvement.

I suppose if small aluminum parts are cleaned and prepped well, a single dunk in the solution will blacken them nicely, but the major drawback is if you try multiple applications, the blackened surface will react with the solution and it'll change colors and fizz creating inconsistent results.

[TommyGunn]

Not like anodizing. Much more like painting.

I've only used it once, many years ago. I don't recall details, but I was not very happy with the results.

Pretty much the same thing here. 

[WLJ]

Hardly adequate for scratches, rubs off super easy.

[Jim147]

Easy off oven cleaner will give an etched grey to aluminum.

[Larry Ashcraft]

I used it a lot at the shop for oxidizing engraving on brass.  It worked great for that, but not so great on aluminum (none of the aluminum oxidizing agents work well on aluminum).  I touched up an "idiot mark" on my competition 1911 with it, and it worked well.

[zahc]

Easy off oven cleaner will give an etched grey to aluminum.

That's from the lye, and the grey is technically smut (alloying elements left behind after al etching). The smut doesn't stay around permanently and has to be etched off with nitric before anodizing.

Rust-oleum sells a special paint for aluminum that I have been curious about but I haven't tried it yet.