Paint anodized aluminum flashlight?

[Sir Housecat]

I was thinking and I wonder if it is possible to paint over
my Fenix LD01's black anodization. I would like to paint it
white because not only would it be cool, but
easier to see if I drop it in the dark when it is off
or in a grain bin/hopper etc...

If I painted over the black anodization with white spray paint,
would it stick or would I need to remove the black coating
for it to stay? Do I need to use a specific paint?

 

[RevDevil]

As with most metal, you would need to sand it to some degree to provide a surface for the paint to adhere to.

 

[fast14riot]

Aluminum receives paint best with an etching primer. As with most things, the quality is in the prep. Clean, clean clean! Once ready to prime or paint, only touch with rubber gloves. Maybe stop by an auto body shop and see if they might shoot it for you for a small fee, you do the prep. Automotive paints hold up much better than store bought spray paint.


-Xander

 

[Gollnick]

All aluminum you have seen is covered in rust.

"What?" you say. "I thought that one of the strengths of aluminum is that it doesn't rust."

Precisely the opposite, my friend. When exposed to oxygen, aluminum rusts almost instantly. Unless you've been in a special lab for the study of such things, you have probably never seen a piece of aluminum that wasn't covered in rust.

Iron rust, iron oxide, is a redish-brown, flaky, weak substance.

Aluminum rust, aluminum oxide, is crystal-clear and one of the hardest substances known, in the same league as diamond. As soon as a layer of aluminum oxide only a few molecules thick forms on the surface of a piece of aluminum, it literally seals the aluminum up so tight that no additional oxygen can get through and the oxidation process, the rusting, stops. Aluminum rust is self-limiting.

In fact, aluminum oxide, aluminum rust, is sometimes called by a different name: sapphire. Every piece of aluminum you have ever seen has been encased in a layer of sapphire! And it's just about as hard to paint sapphire as it is to paint diamond. Most paints just won't adhere.

Roughing up the surface creates microscopic hills and valleys that the paint can physically adhere to.

There are special paints that work better. Power-coating works well.

But, a coat of common paint on aluminum -- well, actually, on the sapphire coating on the aluminum -- just won't adhere well at all.

 

[fast14riot]

Gollnick is right, and why an etching primer is needed.

Fyi, color annodizing is not a "coating" it is a dye in the surface of the Al under the oxide layer. It can even be done with simple RIT dye. It can be dangerous so I won't go into detail about the process, so if you wish to try it at home you are on your own.


-Xander

 

[Sir Housecat]

I suppose I can leave it black then.

Gollnick, that is pretty cool. I did not know that. You said that
Aluminum forms a layer of Saphire as hard as diamond? I wonder
if aluminum would make a good sharpening/honing surface.

 

[JSMcustoms]

All aluminum you have seen is covered in rust.

"What?" you say. "I thought that one of the strengths of aluminum is that it doesn't rust."

Precisely the opposite, my friend. When exposed to oxygen, aluminum rusts almost instantly. Unless you've been in a special lab for the study of such things, you have probably never seen a piece of aluminum that wasn't covered in rust.



Aluminum rust, aluminum oxide, is crystal-clear and one of the hardest substances known, in the same league as diamond. As soon as a layer of aluminum oxide only a few molecules thick forms on the surface of a piece of aluminum, it literally seals the aluminum up so tight that no additional oxygen can get through and the oxidation process, the rusting, stops. Aluminum rust is self-limiting.

In fact, aluminum oxide, aluminum rust, is sometimes called by a different name: sapphire.

You learn something new every day. Even though I'm fairly well versed in welding I'd never heard this.