Why anodized instead of enameled?

[Borad]

I see from the "show us your beat up flashlights" thread that everyone's black anodized coatings are getting worn down to the bare aluminum. Wouldn't enamel be better? I read that anodizing makes the flashlight between .0005 and .002 larger, which is pretty thin. I'm not so clear about the dying part, but the fact that anodized surfaces are dyed rather than painted says something about the difference in thickness.

 

[Borad]

I just discovered that there's thermally conductive enamel and thermally conductive epoxy coating which would allow a coated flashlight to cool off.

 

[tolkaze]

People Cerakote their lights, but aluminium is relatively soft, so if you dint your light, the cerakote comes off in flakes

 

[RBR]

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[Borad]

Another thing I'm wondering is why not enameled steel instead of stainless? Enameled steel would probably be cheaper and more crush resistant. There would be that constant-thickness issue but I don't really see it as a problem because of the o-rings, but I don't know much about flashlight construction.

I just read about an engine enamel that's "fortified with ceramic resins for maximum heat dissipation and gloss retention" and comes in a spray can. I don't know how hot engines get but probably less than 1380°F. It's not made to be held so I'm not sure about its abrasion resistance or safety for skin contact, but there's a clear top-coat available that gives it extra durability.

There's gotta be a better coating than what I've seen on flashlights today. $200-$300 flashlights with coatings sure to get worn just doesn't make sense to me.

 

[daytec]

How about parkerized*sp*?................marty

 

[nfetterly]

DLC - Diamond Like Coating - pump supplier came into the mill I worked in and the inards of the pump (for chemical application) - DLC coated. I pulled out my Haiku (DLC coated).

 

[Borad]

DLC - Diamond Like Coating

That would be Diamond-like carbon. It can be used on aluminum (Corrosion Resistance of Diamond-like Carbon-Coated Aluminum Films). Also see Applications of diamond-like carbon thin films. But I'm skeptical of coatings that are thin for something that will be rubbing against keys for years.

 

[RBR]

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[RBR]

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[Borad]

You mean that seriously ?

:huh:

I would like to see your reaction if your $200,- or $300,- light starts corroding after having had contact with water or, even worse, battery acid or salt water

If the coating doesn't get warn all the way to the metal, it would be OK. Cars are made of painted, galvanized steel and it works for them. But if the batteries leak, that would be a problem over time.

 

[RBR]

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[daytec]

hijack maybe...but,what about parkarizing?

 

[eightbitpotion]

hijack maybe...but,what about parkarizing?

TO make it simple, neither Mn nor Zn parkerizing can adhere to stainless. Techincally there's SOME (very very few) applications where it can work, but you might as well just use bluing instead.... but still isn't as practical as anodizing.

 

[Borad]

hijack maybe...but,what about parkarizing?

I looked it up when you first mentioned it, and that led me to another coating, which led me to another. I looked again, using Google Scholar, and found:

phosphate coatings are often applied to carbon steel and low-alloy carbon steel. This is also known as "bonderising" or "parkerizing"....Phosphate coatings by themselves are not normally used to provide corrosion protection. Their main advantage is in providing an excellent surface for the bonding of paint films.

From Metallic materials: physical, mechanical, and corrosion properties By Philip A. Schweitzer.

 

[Borad]

Enamel and polymer coatings are possible on aluminum. For enamel, firing temperatures are as low as 450 c. Handbook of aluminum: Alloy production and materials manufacturing, chapter 8: Vitreous Enameling, and chapter 9: Composite Polymer Coating.

I don't know whether knurling would be useless with a thick enough coat of paint. A larger texture may be needed. BTW, it's the knurling that's the main culprit in the wear of anodizing. My solitaire has no wear on the smooth parts.