Why do flashlight get anodized?

HighLumens

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I was wondering what the purpose of anodizing aluminum flashlights is. AFAIK aluminum doesn't get attacked by water or air (doesn't rust and doesn't develop any kind of patina) so... why do we need aluminum flashlights to be anodized (any type and color of anodizing)? Do we need it in the first place?
 

Random Dan

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It isn't strictly needed; there are plenty of plain aluminum lights out there doing just fine. Anodizing increases durability and helps with aesthetics. Also it is sometimes it is used to block electrical path through threads so that loosening the threads causes mechanical lockout.

Also aluminum can definitely corrode, just take a look at Land Rovers from the 60s. Not really relevant to flashlights though, unless it's a dive light.
 

thermal guy

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One reason is the looks. Ever seen a stripped aluminium light? Some like the looks but definitely not my style.
 

Timothybil

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It's my understanding that it also protects from dings and scratches. That is why you will see peo0ple making a distinction between HA II and HA III anodizing, with HA III being stronger. Also, it is practically the on ly way to apply color to an aluminum light. One could paint it, but paint can rub or flake off a lot easier than anodizing does.
 

NPL

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Powder coating metals is usually cheaper, but sits on the surface and rubs off with wear. Anodizing embeds color deeper into the actual metal and is significantly more durable to keep it's color even when scratched. I also find that anodizing is less prone to leaving fingerprints. Shiny surfaces are nice when kept clean...

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Thetasigma

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New question. What exactly is ceracoating, and where does it fit in this discussion?

Assuming correctly done anodizing and cerakote.
Where anodizing is an electrochemical process to produce a controlled oxidation of the aluminum to generate a very durable layer of aluminum oxide that is chemically bonded to the aluminum, cerakote is a ceramic based finish that is carefully applied to the part to be finished. Cerakote is essentially a paint so it is only as impact resistant as its base material, in this case aluminum is somewhat easy to flake cerakote off on impact. Cerakote IMO makes more sense on firearms or steel parts where the base material is harder than say an aluminum light.

As for general comparison, anodizing can be more durable to wear and impact but especially the stronger HA type III, is quite limited in what sort of colors you can get. Cerakote while less durable has a plethora of color options available, for example you could get a pink and zombie green on the same light if you really wanted to, anodizing is going to be a singular color as it is colored by dyes in the chemical bath entering the pores and being sealed in.
 
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Kestrel

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My apologies for the interjection of a clarification; there are no such things as HA II or HA III.

There is Type II anodizing; Type III is also called HA.

HA-III is sort of like saying Roger-Roger or Pizza Pizza. ;)
 

CREEXHP70LED

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I like black type lll HA personally because of the way it looks. There is going to be differences even among the type lll HA's though. From Surefire to Elzetta to Malkoff, they all differ. I like Malkoff the best myself, but some old 6p's are very nice too. Does one "need" an anodized light? Maybe not. Depends what you like and what your doing with the light. If you get a colored Elzetta Limited Edition light, they are first anodized type lll HA then ceracoated over the top of that.
 

thermal guy

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I don't even think any but the cheaper lights use type II.i plasma coat for a living and have always wanted to coat one of my lights. Problem is thermal spray doesn't take to well to impact. As far as wear. They do not ever wear. Not with hand use anyways
 

bykfixer

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There is also the PVD process that could be construed as similar to powder coat or cerekote where the coating is in a gasious state and electrically bonded to an electroplate of material(s) over the alluminum. Foursevens blue Paladin and PK's PR-1 used that process.
 

jorn

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Aluminium does corrode. If you own a alu boat, and dont change zinc anodes, well the boat will sink :tinfoil: Also i dont consider bare alu as clean, put bare alu in your pocket, and your pocket will turn black over time. if you rub bare alu at a white wall, it will leave a mark, just like a pencil.
 
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One reason is the looks. Ever seen a stripped aluminium light? Some like the looks but definitely not my style.

Oh...I don't know. :D

Boss70Green.jpg


Boss70Red.jpg
 

Thetasigma

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My apologies for the interjection of a clarification; there are no such things as HA II or HA III.

There is Type II anodizing; Type III is also called HA.

HA-III is sort of like saying Roger-Roger or Pizza Pizza. ;)

Thanks for the clarification.
 

focusworks

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Bare aluminum will turn your hands black if you handle it a lot. Anodize is very durable and while you need to get it off of electrical contact surfaces because it's non-conductive it improves the thermal conductivity of aluminum. That's never a bad thing on a modern light.
 

Skaaphaas

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Bare aluminum will turn your hands black if you handle it a lot. Anodize is very durable and while you need to get it off of electrical contact surfaces because it's non-conductive it improves the thermal conductivity of aluminum. That's never a bad thing on a modern light.
This last bit is most interesting. Would you mind elaborating on it? How does it improve the thermal conductivity?
 

aginthelaw

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There is also the aesthetic value of anodizing. Look up tj's custom gunworks to see some of his work with anodizing
 

bykfixer

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This last bit is most interesting. Would you mind elaborating on it? How does it improve the thermal conductivity?

No blanket on the outside. The anodize coating could act as a thin layer of insulation. I say could because some desingers build their ideas around the properties of the annodize layer to achive a more efficient conduit.
 
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