I just anodized my first piece of Aluminum. It's not too hard to do. Now I can start making bodies, extension tubes and even hybrid copper/aluminum pills.
This is just a scrap piece that has not been polished in any way. It was parted off, cleaned and anodized.
I gave it a decent scratch test with a knife. It held up well.
For those that are curious, here is the method.
Clean the part. This is probably the most important step.
Put in battery acid bath (50/50 battery acid and distilled water)
Put a constant current to the part for a set amount of time which is figured out using the square area of the part.
************************************EDITED TO ADD FORMULAS***********************************
Formula 1: Amps per ft2 = Amps * 144 / in2
Shoot for 12-20 amps per square foot (ASF) for Type II Ano
Shoot for 24-40 ASF for HAIII
Formula 2: Time in minutes = 5 * Square inches * desired thickness in mils / Amps
Type II thickness is 1mil or less. Don't try for more.
HAIII requires a cold sulfuric acid solution.
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Dye the part. I used Caswell's dye in 140 degree bath.
Seal the part.
Sealing can be done in just regular boiling distilled water or an additive from Caswells can be used.
Done.
Reflectors can be anodized too with very high reflectivity. It may be the best way for us to repair damaged reflectors. It has to be easier than vapor deposition.
Well done, can’t wait to see where you go with this.
(Might even have a project for you 
)
Down the road a ways, we’ll see…
I did some more scratching on the test piece and on a D Mag. The ano on the test piece seems to be pretty close to the Mag in scratch resistance. Does anyone know if Maglights are Type II ano? They must be.
would love to see a vid on this :)
Excellent work! I’ve always wanted to try this.
As GTamazing said. Very nice work again. Loving your work.
Thanks to all. It seems that my hobbies are multiplying!
Nitro, a video would be pretty boring. Except for some bubbles, not much going on. All of the work is really in the cleaning.
yes, M@Gs are type II anodizing. To achieve type III “hard anodizing you need more current and a way to keep the acid cold. There are plenty of websites and vids that show what you need for parts/chems/ etc.
Thanks for confirming that Mags are Type II. My understanding of Type III (Hard Anodizing) is that one needs 1) Double the amps per square foot compared to Type II. 2) Cold sulfuric acid solution (32-40F). 3) Agitation of sulfuric acid solution.
I have the first 2 (at least while it's winter here). Need to figure out how to agitate it. I may have to settle for something short of Type III, but I should be able to do better than regular Type II.
When you say agitate I’ve seen videos where they use a fish tank aerator. Don’t know if it does the same thing.
Yes, I thought about using compressed air with a glass pipe to the bottom but I don't want extra oxygen getting in there. Plus the fumes would be bad. I was thinking more along the lines of the high school magnet in a pyrex dish gizmo. Just enough to keep the solution moving should be good enough.
From my experience turning maglites, some are harder than others. I have turned some that would dull tool steel in a matter of a minute. I would assume the anodizing was close to 50 RC since the tool steel was around 60 RC. I have read that a hardness of 55 RC can be achieved from a type II coating. Type III can be from 50 RC to 70 RC. So a Maglite coating is not far behind a type III anodizing. As long as they have been produced and as many that has been made, I would bet that they pretty well have the process down pat. I would assume its about as good of a type II anodizing you will find.
I have always used Rit clothing dye for coloring. Sunshine Orange is one of my favorites.
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I would recommend that you use a professional dye for black. The Rit black doesn’t turn out black, more like a dark grey with a hint of purple.
007, do you use a sealer or just boil in distilled water? Or no sealer at all? I've read that sealing is beneficial with the cheaper dyes, but that it somewhat softens the ano. So there is a tradeoff.
I bought black from Caswell. Pricey stuff.
Nice job!
I’ve heard that without a dye, the anodizing turns out clear, but is there a white dye that can be used?
Also, is aluminium the only metal that can be successfully anodized to a hard coating?
To my knowledge, white is not possible with ano. Yes, clear is undyed.
Titanium is also anodizable if that is a word.
I would love to have some unique colored lights, apart from the usual black and grey.
Interestingly, this company seems to do white colored anodizing?
http://www.allianceorg.com/aluminumextrusions_colorsandfinishes.html
As for the sulfuric acid… is there a reasonable place where I can get my hands on these?
Interesting. I've never seen white ano dye and the couple of things that I've read about it say it's not possible. Maybe they have figured it out.