DIY aluminum molded cases and reflectors. Scouting for info.

[yo6ial]

Hi.
As I have some ideas to make aluminum cases for led lights, I'm searching for more info about possible home-brewed casting methods. Moreover, i think i could make even aluminum reflectors, using some polycarbonate led lenses as die templates.
My setup, for now, is an electric kiln, aluminum scrap and two tons of drawings and designs
I intend to make simple ceramic dies, perhaps starting with the lost wax method.
But, if all this will be relatively easy and the processes involved are well understood by me, i don't intend to let those cases in they're natural color.
After some mandatory milling, and polishing... some protective black color will be a must.
Anyone knows some homemade methods of anodizing? (ok, not quite homemade but more of a small shack)
And the reflectors, witch will be the first I'll set myself on.
Molding, cleaning, milling, polishing and... here comes the hard part, coating.
I plan to use the electronic deposition method, as in a vacuumed charmer, the part is connected to the positive side of a high voltage supply and an electrically heated cathode will heat the metal to be deposited on the reflector.
What metal should i use for reflectors coating?
Can I use Chromium or Nickel, on top the copper 1st coat?
What metal is used in coating those marketed aluminum reflectors?

Thanks for reading

 

[Der Wichtel]

Aluminium can be used for the coating as well and will be very reflective.

http://lerch.no-ip.com/atm/Allum.htm

 

[yo6ial]

I know aluminum has good reflecting proprieties but... when exposed to air and becomes dull in seconds after polishing or electronic (ionic) deposition.
I'd like to coat with a more inert metal, like the coating of cheapest plastic reflectors.

 

[Al Combs]

I know aluminum has good reflecting proprieties but... when exposed to air and becomes dull in seconds after polishing or electronic (ionic) deposition.
I'd like to coat with a more inert metal, like the coating of cheapest plastic reflectors.

I remember years ago reading about vacuum coating telescope mirrors. Aluminum deposited by vacuum deposition is only a few angstroms thick and extremely delicate. The only reason aluminum on say a screen door dulls is because of the other elements used in the alloy. If you use pure aluminum, the oxide will be clear. Years ago I ground and polished a 6" f/8 telescope. When I was finished polishing, I sent it out to have it aluminized.

Sorry I don't know how flashlight reflectors are coated. I always imagined because vacuum coatings were so thin that flashlight reflectors must be electroplated. Based on the assumption that the orange peel effect was done by coating and not machining. But like I said I don't know that for sure.

Good luck

 

[65535]

I think standard reflectors are electroplated due to the cost effectiveness. Vacuum coating with static depositing would theoretically give you a very fine reflector for a good throw if you could polish it properly.