Is it possible to do "clear" anodizing?

Is it possible to do \"clear\" anodizing?

So i've read up on the basic anodizing how-to by Chief_Wiggum, but i'm not clear on one thing - is it possible to skip the dye step and end up with clear anodizing? Ie parts that are anodized (Type II) but not colored?

If so, this would be awesome! Does anodized aluminum conduct electricity? (I'm guessing it will because its Al2O3 right?)

Re: Is it possible to do

I think what you are refering to is Natural HA, take a look in the Sandwich Shoppe for the new PR-T heads, one of them is Natural HA. It appears to be kind of a dull Aluminum color.

Take a look at the head in this picture.

Re: Is it possible to do

I read in another thread which I cannot find right now that this was possible, but something was difficult about it ...
bernhard

Re: Is it possible to do

[ QUOTE ]
FlashlightOCD said:
I think what you are refering to is Natural HA, take a look in the Sandwich Shoppe for the new PR-T heads, one of them is Natural HA. It appears to be kind of a dull Aluminum color.

Take a look at the head in this picture.

[/ QUOTE ] Isn't Natural HA what is done with the Arcs and almost everything else? As in Type III, comes out matte gray? I want clear anodizing, that comes out looking shiny silver like raw aluminum - like the Elektrolumens Tri-star and FT-3C.

I want the looks of shiny aluminum, with the protection of anodizing. /ubbthreads/images/graemlins/naughty.gif

Re: Is it possible to do

The anodized aluminum that I've tested does not conduct electricity.

Re: Is it possible to do

[ QUOTE ]
LightScene said:
The anodized aluminum that I've tested does not conduct electricity.

[/ QUOTE ] Well that would put a biggie-sized wrench in my plans - i was thinking of clear anodize all over because its not possible to do just the outside. And i love the look of shiny aluminum.

Re: Is it possible to do

None of my anodized lights are conductive.

Re: Is it possible to do

Aren't the "silver" PM6 and X5T clear anodized?

Re: Is it possible to do

My question is can we use dye to create a lighter-colored HA III surface, say silver?

Re: Is it possible to do

If you are talking DIY, I believe Chief Wiggum and others have indicated that the power needed for the anodizing and cooling of the mix makes HA III unlikely for DIY.

Re: Is it possible to do

[ QUOTE ]
Mark_Larson said:
[ QUOTE ]
LightScene said:
The anodized aluminum that I've tested does not conduct electricity.

[/ QUOTE ] Well that would put a biggie-sized wrench in my plans - i was thinking of clear anodize all over because its not possible to do just the outside. And i love the look of shiny aluminum.

[/ QUOTE ]

Clear anodizing is used on almost all consumer products made of aluminum-- without it, the metal would become dull from exposure to oxygen, moisture, and environmental chemicals. A clear anodized surface looks glazed or very subtly grainy compared to a bare polished aluminum surface.

However, both clear and color anodizing can be "masked" with plugs, wax, or other coatings; or they can be selectively removed after anodizing is complete. Many commercial flashlights have the contact surfaces of mating parts peeled down to bare metal even though the components are anodized inside and out.

Chalo Colina

Re: Is it possible to do

I was just at a new anodizers yesterday, and they do a "Sanford" process HA, which is pretty clear, and is HA. I saw several examples, and the finish looks like a cloudy, recognizably metal finish. I think that is the closest you can get using HA undyed. If you can find a local anodizer that does the Sanford process of HA, you may be able to get a "clear" HA.

BTW, I was there looking at samples for the next run of the Firefly - it's going to be gorgeous (and NOT black, or "HA natural"). (Sorry for the OT content). /ubbthreads/images/graemlins/grin.gif

Re: Is it possible to do

can this annodyzer do black?

i need to get some pieces black ha3ed! /ubbthreads/images/graemlins/rant.gif

Re: Is it possible to do

Hard Anodizing penetrates the surface of the aluminum, hardening the aluminum. True HA will be grey, or shades of grey. Depending upon how long the part was run.

It's not possible to have a clear hard anodized part.

I just posted a detailed description in this post: http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB3&Number=444589&page=&view=&sb=5&o=&fpart=2&vc=1

Re: Is it possible to do

Roth, they do a nice black HA3. I saw several samples, and the quality is quite good. Depending on the surface finish you have on the parts, their black HA3 can look as good as the regular type 2 anodizing.

Cy - I thought so too, but the Sanford process HA, whatever that is, is MilSpec (they do parts for the US military), and can be much clearer than the other kinds I've seen. The colours they can do are much more vivid, also.

Re: Is it possible to do

According to the box sticker, the "silver" SureFires were clear anodized.
I've also got a yo-yo or two that are clear anodized.
I haven't checked whether they're conductive but they have a brilliant platinumy look to them.

Re: Is it possible to do

cy's description in the linked thread was very good. He did anodizing for a living so, though he refuses to except the "expert" moniker his previous demonstrations of expertise on the subject makes his views an outstanding source.

The Sanford process is two-step coloring as described in the linked thread by cy and (seems to me) correctly refereed to in this thread as a HA by Dspeck. The Sanford process is complicated by the second step of pigmentation. If the processing isn't done just right it defeats itself to a certain degree. I think it's pretty neat to know that Doug and Peter use this technique for richly colored Type III. My preference would be standard Type III matte black which is dark, charcoal grey.

What about military specifications?

There are mil specs for clear anodized aluminum for military aircraft. I can't remember what they are. Here are some mil specs that relate to the topic:

There are 3 basics types of anodizing (Type I, II, and III) which are Chromic, Sulfuric and Hard Coat.

CHROMIC ANODIZING Type I MIL-A-8625
SULFURIC ANODIZING Type II MIL-A-8625
HARD ANODIZING Type III MIL-C-5541

Obviously, just because a treatment has a mil spec doesn't mean it is HA III. But mil spec MIL-C-5541 is HA III.

Here is a definition that may help the topic:

Clear anodized metal: Metal with a substantially colorless, translucent anodic oxidation coating.

Here are some benchmark terms we might convene upon for naming.

Type I chromic anodizing can be clear or pigmented. It is usually clear.

Type II sulfuric anodizing can be clear or pigmented. It is usually pigmented.

Type III HA is shades of grey all the way to charcoal and can also be pigmented. It cannot be clear.

Sanford Process is Type III HA double dipped pigmented.

From this I would pose that an EL Tri-Star silver anodized is probably Type I clear sealant. It could be Type II. A silver PM6 is probably Type II silver pigmented. An elusive E2E HA III black is probably standard HA III possibly cold cooked with a small amount of black pigment for 45 min. +.

A Firefly is probably Sanford Process Type III HA.

How does all this address the original question?

Is it possible to DIY clear anodizing? First, I understand Mark Larson's logic and it immediately seems possible. I would think Chief_Wiggum probably knows. Maybe that tall dude with large feet knows. I'm sure that some of the MIB guys know. I would also say that if it is possible it should be a Type II sulfuric acid process as Type I chromic acid is bad MOJO. Sulfuric acid is scary enough but chromic acid processing has heavy "forever" components in regard to health and environment concerns.

Re: Is it possible to do

Icebreak,

I have been having aluminum parts anodized for 35+ years. I don't pretend to know much about what happens behind the receiving counter. Most often it has been Type II, Class 2 in various (can be vivid!) colors. Some has been "HA"- Type III, Class 1. It is always grayish, sometimes towards a green/gray. Different alloys vary in color- castings will typically have pits. I know they can pigment it, but it results in a "matt" color. I concur that "HA" cannot be "clear," and I am unaware of "silver" pigments. "HA" will dye black with no problems. DIY Type II home anodizing is very doable- the Chief is having fun (I hope!) (Sulpheric acid is the best drain opener, and fairly environmentally-frendly /ubbthreads/images/graemlins/grin.gif ) I have a flashlight job coming-up where I will try abrasive blasting prior to "HA" to try and achieve a SureFire-class finish.

Larry

Re: Is it possible to do

Larry -

Great answer.

Surely, Type II Class 2 "vivid colors" includes silver?

I thought the pigmentation of the surface of the metal came from a combination of the anodize and the dye. I thought the colors in Type II were the dye. After re-reading your post a few times it seems I was wrong about this.

On your next creations:

Abrasive blasting? Can't wait to see the outcome.

Jeff

*** edited after re-reading tvodrd's descriptions ***

Re: Is it possible to do

Check out TNC custon products. Chris sells his lights silver anodized and it looks nice and shiney to me.
www.tnccustomproducts.com