Purpose of Hard Anodized Finish??

[senna94]

The 2 Surefire lights I have dropped with HAIII finish from about 3 feet to concrete and ceramic tile have both resulted in damage to the finish exposing the bare aluminum. Aside from a good looking finish I really don't see what use the HA is. Bare aluminum really doesn't oxidize so that pretty much rules that out. I think a rubberized finish would be more durable even though I am certain it would deminish the aluminum body's ability to dissipate heat. Any thoughts??

Paul

:huh2:

 

[Brighteyez]

The Streamlight Scorpion has a rubber or vinyl finish and it doesn't appear to have heating issues, nor do light like the Dorcy Spyders that are also clad in a rubber grip. You can probably use that liquid vinyl stuff that they sell at the hardware store and dip or brush the vinyl onto your Surefires. Be careful around the tail cap though, you don't want the switch sticking.

The 2 Surefire lights I have dropped with HAIII finish from about 3 feet to concrete and ceramic tile have both resulted in damage to the finish exposing the bare aluminum. Aside from a good looking finish I really don't see what use the HA is. Bare aluminum really doesn't oxidize so that pretty much rules that out. I think a rubberized finish would be more durable even though I am certain it would deminish the aluminum body's ability to dissipate heat. Any thoughts??

Paul

:huh2:

 

[greenLED]

Aside from a good looking finish I really don't see what use the HA is.

HA is a great barrier against abrasion, but not against physical impact (the impact deforms the softer metal under the aluminum aoxide layer).

I guess we've raved so much about HA that those 2 have become mixed up, but that's not the case at all. Regardless of how you coat aluminum, the underlying material will deform given a strong enough impact.

 

[Planterz]

It's difficult to make a comparison between the hardness of HAIII and other known hardnesses (like knife blades) because the usual method (involving a press putting a dimple in the material) for Rockwell testeing doesn't work well because of the soft aluminum underneath.

Instead, you can make a comparison with abrasion resistance tests, in which case you can figure that the HAIII coating on aluminum is upwards of 90+Rc hardness. That's pretty damn hard, and can't be scratched by keys, change, or even knife blades. Most "scratches" that develop in HAIII coating are actually what got rubbed off of the other object and is now embedded in the HAIII.

The weak point of HAIII isn't in the coating itself, but rather the soft aluminum underneath. If you drop your flashlight, you can dent the aluminum, which can chip the HAIII. But when it comes to scratch resistance, even hardened steel comes up short to HAIII coating.

 

[Lobo]

That's a question I've asked myself a couple of time. Is there really any purpose of HA except for the light to look nice? It seems kind of funny to me that this is so important, especially in "tactical" lights. I have a hard time believing that the people in the line of fire demands that their lights should look shiny and new also. Are they supposed to be used or to be admired shelf queens?

 

[cutlerylover]

Given the options having bare aluminum would not be a good as having the cpating on there...It may not seem like iots doing much but Im sure if you dropped a similar light without the coating you might see the difference...

 

[tacticalstuff]

one good reason for HA III is so that you can further "justify" buying a bloody expensive light.

you tell the wife -"But it's hard anodised type III which is really tougher than tough!"

 

[cutlerylover]

well you better have a hard head too cause I know if some guys tell their wife that they are gonna get a wack in the head, lol...

 

[chesterqw]

well, no one told you that HA protects the light from gouge(s)...

and, even if you have a very protective coating, dropping it will still make a few gouge(s)
on you light.

heck, trying dropping it from 100meters.

 

[TORCH_BOY]

With Ha the light feels better in the hand

 

[aml]

HAIII doesnt reflect IR.
ano also electrically isolates the AL.

 

[batman]

if you remember the surefire story where a 6P deflected a bullet, saving a cops life, then still worked...that was type II anodized my friend...therefor we can make a logical assumption that even if it were just bare aluminum with no coating whatsoever,..it holds up just as well to gunfire and compression, impact, etc. if i put a 6P and an A2 in my vice and started crushing down,..there wouldn't be any difference in the lights i guess.

I think flashlights should be made of a harder substance than flimsy aluminum. Titanium yes, but obviously too expensive. i can think of like 5 billion materials that are harder than aluminum, geesh. why?

 

[AndyTiedye]

It's for that "military surplus" look.

I'm going for splash anodize myself.

 

[Size15's]

Hard Anodising is not a coating - it's a growth.

 

[Perfectionist]

Personally, I love the look of Chrome ....

 

[socom1970]

Hard Anodising is not a coating - it's a growth.

What Al said. The 2006 Surefire catalogue (Page 5) explains it a bit along with pictures. That is another reason why it doesn't rub off or scratch easily. It doesn't coat the metal, it is a part of it, bonded to the aluminum at a molecular level through electro-chemical growth. Quoted from the Surefire 2006 catalogue, "The anodizing process (from anode, the positive side of an electrical circuit) uses electricity and a chemical bath to "grow" a layer of aluminum oxide on an aluminum surface. Aluminum oxide is the second-hardest substance known to man, exceeded only by diamond." Definately cheaper to coat Surefire illumination tools with Hard Anodizing than with diamonds!!!

 

[tacticalstuff]

well you better have a hard head too cause I know if some guys tell their wife that they are gonna get a wack in the head, lol...

thats a good one!

time to buy kelvar helmets for the complete SWAT look...

 

[lightplay22]

All raw (uncoated) aluminum I'v ever handled left nasty gray smudges on whatever it rubbed up against. I definately would not have an aluminum flashlight that had no coating whatsoever on it.

 

[GarageBoy]

That grey smudge would be aluminum oxide rubbing off

 

[greenLED]

Hard Anodising is not a coating - it's a growth.

Man, I thought you were going to give your speech about HA and TypeIII.
:laugh: