# A strong finish? HA3 vs. powder coat vs. enamel



## milkyspit (Jun 8, 2004)

Could anyone educate me on potential finishes for my custom flashlights and other metal creations? I've been focusing on hard anodized (HA type III, or HA3 for short) aluminum for the really topnotch lights in my collection, mainly because I want a finish that will offer maximal protection to the lights for a long time. But as a modder, my understanding is that HA3 is kinda tough to get done unless I've got LOTS of pieces to do, so do I have any alternatives?

I've always liked the finish on products I've seen with powder coat (mainly lawn chairs, appliances, etc.), so is this an option for the small-scale modder? I'm guessing that a shop would be willing to powder coat a few pieces much more readily, and economically, than I'd manage to get a few pieces hard anodized... but I really don't know if that's true or not.

Then there's enamel. The enamel-coated steel pots with which I've cooked in the past seemed to have a pretty tough finish. Is enamel an option, and is it the same as the enamel paints available at the hardware store or perhaps a hobby shop... or is the "pot" version of enamel something completely different?

Bottom line: for those of us who won't be ordering piles of pieces to be hard anodized a la McGizmo or MR Bulk, what viable alternatives to we have that will result in a nice, strong finish? /ubbthreads/images/graemlins/confused.gif

Thanks all! /ubbthreads/images/graemlins/grin.gif


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## wasabe64 (Jun 8, 2004)

I've often wondered about powdercoating, but the pigments are epoxy or polyester-based, so heat dissipation may be an issue.

Count me interested as well. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/popcorn.gif


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## GJW (Jun 8, 2004)

Pretty sure I've seen home powdercoating setups.


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## tvodrd (Jun 8, 2004)

Milkeyspit,

All 3 can chip, and a professional powder-coating shop is also likely to have a "lot minimum charge." There are polyurethane finishes (think of plastic auto bumpers) that are about the toughest thing going. I am ignorent as to whether they're catalyzed, eg Dupont's Imron. (Which might not be a bad choice.)

Larry


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## HarryN (Jun 9, 2004)

Scott, it is all in the eyes of the beholder.

I have some samples of type II, and various powder coatings - they are nice, and seem fine, until someone like Craig at the ledmuseum does a scratch test- fails instantly. My experience was the same.

The polymers can be baked on, a good example is high end auto paint, and they are pretty tough (also, poor conductors, as pointed out)

You might want to test some of the industrial spray paints for small projects. You might be surprised how tough they really are after proper curing, but make sure you use the right primer for Al.


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## Al_Havemann (Jun 9, 2004)

Bead blast it and leave it natural - nothing to scratch then. Bead blast setups are inexpensive. Powder coat scratches just like a car finish, Enamel - like the kind on pots, is closer to a ceramic than a paint. It's plenty hard enough but it will chip and it's not cheap to get done in small batches.

HA is probably the best choice if you must coat it but frankly, a nice bead blast finish looks just as good to me.

I’d rather have nothing to worry about. For instance; a while back I had a beautiful Klein Rascal mountain bike, that bike was a feast for the eyes with a dramatic rainbow fade paint job. I didn’t want to risk scratching it so it stayed home, a waste of a fine machine. Now I have a titanium frame hardtail with no paint to scratch so it get used a lot. Same with flashlights.

Al


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## MoonRise (Jun 9, 2004)

It depends on exactly what you want the finish to do.

HA3 - tough. It's not a coating, it's the aluminum itself. It would be the hardest (hence scratch resistant) finish you could get on a piece of aluminum. Won't chip off, but color choices are more limited. Heck, I scrub some of my HA3 cookwear with a ScotchBrite pad! /ubbthreads/images/graemlins/smile.gif

powder coat - It's just paint, dude. If you want a painted flashlight, you could just do it yourself. /ubbthreads/images/graemlins/smile.gif Lots of color choices, but paint is not going to stand up to handling wear. And paint is a relatively thick coating.

enamel - The enamel on cookwear is a ceramic coating. Very hard, but that hardness means it is brittle and hence can chip. Enamel paint is just paint.

Your choice. What do you want the finish to do?


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## milkyspit (Jun 9, 2004)

The finish would be to protect the aluminum from dings and scratches, as I might get if I dropped a light on rough concrete, a gravel driveway, a random rock in the woods, etc., not to mention incidental bumps against other household items from doorways to appliances and the like. Plus keep the flashlight in good condition when the 4 year old decides to whack it with a butter knife, or maybe drum on it with his drumsticks! /ubbthreads/images/graemlins/ooo.gif

These are the challenges I face in my daily life, and I want my tools (including my nicer flashlights) to stand up to them as well. Minor scuff marks and small chinks in the armor here and there, developed over time I can handle, but chips of finish removed and gouges down to the bare aluminum drive me crazy.

That's why I go for the HA3 finish from the big boys, but when I craft stuff myself I want it protected just as well, if that's at all achievable.


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## kj (Jun 9, 2004)

Scott,

It may be a little off topic, but have you looked for anodizers/platers which accept a small order from an individual? I did look for such anodizers in Japan and found a few that meet my criteria. I guess you can find some as well in U.S.

Just for your information...
<ul type="square">[*]An anodizer takes an order from just one piece. They charges $6 per a piece for HA. I ordered the black HA and the result is nice. I've not ordered the natural HA yet, but I heard the color of the natural HA was light. Still, it should be durable enough.

PICT (Left: Stock Solitaire, Right: HA black done by this anodizer)
.  [*]An anodizer requires 100 square centimeter of surface area and charges $100 at minimum, but I still think it's small. I did ask them to adjust the color to SureFire/Arc and the result was good. I made an order to hard-anodize seven McLux PR heads and it cost $110. The price will not change if I ordered a few more or less.

PICT (Arc-Sure Adapter and McLux PR-T head were anodized by this anodizer)
PICT (Left: from Sandwich Shoppe, Middle: by another anodizer below, Right: by this anodizer)

To get a semigloss finish like SureFire, the surface need to be roughened a little before anodizing. It seems a bead blasted finish is too rough and this anodizer used an alkaline.
.  [*]An anodizer takes an order from just one piece. The result was good but the price was high. It costs $60 to hard-anodize one McLux PR head. If I ordered another, the cost would be doubled.
[/list]
These HA may not meet criteria defined in the MIL spec, but I myself don't care about this much.


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## HarryN (Jun 9, 2004)

There is one more potential option - go to a harder Al alloy. Most lights are built with 6061- T5 or T6, but if you go to one of the higher end alloys, such as 7000 series, this is actually stronger and I think available in a harder temper.

Bead blasting / sand blasting is not a bad way to go. If it gets a scratch that really bothers you, just sand blast it out again.

I have seen people just do the "sealing step" of the anodizing process, which is more or less DC current through the part while immersed in hot RO water. Certainly, this is not able to offer the color options, but is a little more hobby oriented than hot H2SO4 in your kitchen sink.

Black is a cool finish color for men, but I bet your wife will actually like a silver color better.


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## Minjin (Jun 10, 2004)

Slightly off topic, but have you guys tried por15 in place of powdercoating?

Mark


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## greg_in_canada (Jun 11, 2004)

*Bare aluminum?*

Doesn't bare aluminum leave black marks on hands
etc? I've bought sheet aluminum for (non-flashlight)
projects in the past and it seems to blacken my hands
from hanlding it. Maybe it was just residue from 
rolling or whatever.

Greg


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## Reptilezs (Jun 12, 2004)

*Re: Bare aluminum?*

the black stuff is aluminum oxide. it comes from reacting with oxygen in the air


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## gadget_lover (Jun 12, 2004)

*Re: Bare aluminum?*

I was just reading up on electroless nickel (EN) plating. It appears to be very tough and will apply to most surfaces. Is it cheaper than anodizing?

Daniel


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## capnal (Jun 14, 2004)

*Re: Bare aluminum?*

Milkyspit
This is a really good question. Part of job is helping identify proper or the appropriate finish required for parts. I wanted to help throw out some information here for you that may help you understand. Some of the replies that were posted here were not correct. As this is actually what I deal with on a daily basis, here are some points...
First, here is a link that will help you understand what happens during the anodizing process... Anodizing Aluminum Anodizing is a great finish, and I think you are correct in thinking that you will need to get lots of parts done in order to make it cost effective. That is true, and true of enamel and powder coating, as well. What you might try to do is call around to some local anodic deposition type service centers and see if they will let you come down there to view the process. Most will, especially if they think you are a potential customer. If you build up a friendly relationship with one, it would be easy for that vendor to just throw in a couple of extra parts next time he is doing that particular batch process.

In powder coating, the difference is all in the type of powder you specify. There are dozens of different types of powders and makers. Types include epoxy, polyester, urethane polyester hybrids, UV stabilized, and lots more. powder coatings Basically, in most powder coating applications, the process involves the part being negatively charged (grounded) and an ionized charge being applied to the powder particles as they are shot through a gun (sometimes called corona charging). powder spraying They adhere to the part, and then the parts are baked, usually at 400 degrees or higher. Lots of powders offer good performance.

Enamel most often refers to wet painting. This process is also applied through a gun, and then requires baking, usually around 200 degrees or better. As with the anodizing, perhaps you can call around to coating houses and see if they would be willing to let you squeeze in some parts if they are running the color or product you are looking for.

HarryN made a good point by mentioning a different alloy of aluminum stock. For example, the 7000 series (7075) in a casting is what the receivers of M16 rifles are made from, just FYI. That might be a consideration for you. And on that point, are you limited to only using aluminum? I realize the benefits of low weight, but there is another process that I could tell you about that applies only to ferritic materials (steels).

Hope this information helps.


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## tvodrd (Jun 14, 2004)

*Re: Bare aluminum?*

M16 receivers are machined from _forgings._ /ubbthreads/images/graemlins/smile.gif

Larry


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## raggie33 (Jun 14, 2004)

*Re: Bare aluminum?*

they was just doing powder coating on a show i wathc called american choper and i heard em say if they hit it with hamer it will bend rather then chip off. they powder coated a bike frame


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## milkyspit (Jun 14, 2004)

*Re: Bare aluminum?*

Hey raggie! I was watching that show too! /ubbthreads/images/graemlins/grin.gif

Capnal, this is great info. Thanks! /ubbthreads/images/graemlins/thumbsup.gif

Er, how does something like titanium nitride plating fit into all this? /ubbthreads/images/graemlins/icon15.gif


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## tvodrd (Jun 14, 2004)

*Re: Bare aluminum?*

Titanium Nitride is an extreemly hard, very thin surface coating. It is typically aplied in a vacuum chamber and is common for cutting tools like drills and endmills. The coating improves cutting tools by being "slipperier" than bare HSS or tungsten carbide. Less cutting fluid is required and with cutting fluid, tool life is increased. IMO, if you don't mind your flashlight looking like it is gold-plated, it is a good finish. I have a Ti and Tungsten light that would benefit from it, but it is expensive for small batches.

Larry


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## Chop (Jun 15, 2004)

*Re: Bare aluminum?*

I kind of agree with the bare aluminum theory. I've done a quite a few lights and went with bare aluminum on all of them. The reason is that in the long run, they generally stay looking better than coated lights. In my case, I'm talking about HA3'd Surefires. I have a KL4 that I modded a while back and it's been my EDC for a while now and it looks it. It's all dinged up.

The HA3 is very tough and does resist scratches, but it doesn't do much to protect from dings. It just can't add anything to the tensile strength of the aluminum that the light is made out of, so when you drop it, it dings or dents. Over the long haul is makes for a very ugly light. My bare aluminum lights, however, have retained a better overall appearance, inspite of the dents and dings because you don't have an OD or black finish with specks of aluminum showing through.


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## McGizmo (Jun 15, 2004)

*Re: Bare aluminum?*

I have a home kit for powder coating and the finish is superior to most paints. The rub is in the fact that it does build and you need to mask and have a clean break at the mask point. I have thought about powder coating a flashlight but don't think it would look to hot at the joints.

Linear Polyurethane paint like Larry suggested is a great coating but the good stuff is expensive, typically three part and a ***** to paint on a cylinder! /ubbthreads/images/graemlins/icon15.gif I would think that this coating might be the most durable of all but probably the most difficult of all to apply. The commercial airlines are painted with LP as are most of the fine yachts. I suspect that a proper coating would require an undercoat primer or "tie" coat for a good bond. Forget it. /ubbthreads/images/graemlins/frown.gif

The hard anodize as well as other hard coatings are great on abrasion but can't protect the softer substrate from deformation on impact. A well bonded hard coat will hopefully remain in most areas but chipping is bound to happen. There is a lot to be said for leaving it raw if you don't mind the color. 
/ubbthreads/images/graemlins/icon3.gif


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## FNinjaP90 (Jul 30, 2004)

*Re: Bare aluminum?*

Sorry to revive this old thread, but I also have some questions on plating.

How does Titanium Nitrate compare to Black dyed HA3 in terms of color, gloss, cost, and durability?

Can a flashlight duplicate the finish of the Movado Valor watch? Can aluminum be coated with tungsten carbide or is it only steel that can be coated?

My local plater said that he could do dyed HA3. I've seen HA3 black and HA3 blue, but does anyone have a picture of other colors? Green or orange maybe?

Can HA3 be done in light gray or silver? White?


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## cy (Jul 30, 2004)

*Re: Bare aluminum?*

What a lot of good information!

Since I use to work at a plating shop. I've done powder coating, electroless Nickel, chrome, hard chrome, copper, nickel, gold, cadium, zinc and all types of anodizing including hard anodizing. Whewwww...

Aluminum has some pretty tuff bonding requirements. That is getting coatings to stick. The first layer is the critical layer in plating. After you get the part really clean, a chemical etch is done on the aluminum. This is so the next layer will bond to the aluminum. 

From my experience the plating that forms the tuffest bond is electroless nickel. After cleaning and a chemical etch. The part is suspended in a heated solution of electroless nickel. The plating is done by chemical reduction. No current is used. When the solution is depleted, back then we dumped into the sewer. Which I though was questionable at best.

IMHO the three best choices are bare aluminum, HA and EN (in no particular order). 

1. Hard anodizing's weakness is: assuming you get real HA and build up to 1mill. The top .5 mill of HA is extremely hard as HA actually penatrates below the surface. below that the sub-surface is still soft. So dropping your HA light on the concrete crushes the top layer and you get a hard to fix dent. Masking off threads is a necessity due to HA being a good insulator. This is a major chore (more expensive) for the plating shop. it common to have leakage from the masking. Also another risk is if you don't maintain solid contact thru the entire anodizing proccess. The part stands a chance is being destroyed. it's common to run 150-200 amps thru the part for 1+ hours. 

HA is accelerating the natural oxidation proccess. generally the darker the HA, the thicker the surface. light HA is simply HA that is not as durable/thick. This is why it's not possible to have clear HA. Dyed HA masks the actual thickness of the anodizing. That's why I perfer natural HA, it's honest. Color anodizing's (type 2) film thickness is thinner than HA, 50-75amps for 20+ minutes. Surefire has some of the best quality controls in the business and it shows in the HA quality in the lights. It's the standard others need to meet. Arc's HA quality is right up there with Surefire. 

2. EN or electroless nickel bonds the best of any plating to aluminum. (HA is not a plating, it's actually a surface treatment) The build-up of EN is the most uniform of any plating. You still need to account for the build-up as 2-3mills+ is normal for any plating. Almost all plating looks good fresh out of the vat. It's what happens a year later when the chemical bond lets go and the plating starts to bubble. I highly recommend EN. Also there is less prep time as you don't need to mask off threads. (you do need to account for plating thickness along with HA which adds 1mill)

3. bare polished aluminum will naturally form it's own thin anodic film. You can dip the part in hot water for one minute if you wish to seal the part. it will dull the finish somewhat. The disadvantage of bare aluminum is it's very soft. Will dent and scratch easily, but being soft. it's also very easy to polish most of the scratches off. It's amazing how easily aluminum polishes. try not to leave bare aluminum wet. it will start to oxidize deeply, which you don't want. salt water of course is bad.

4. Powder coating is among the tuffest of paints. but it's still a paint. the positive charged power is shot on to the negitive charged part. the powder wraps around the part giving a very uniform layer. VS spraying conventional paint you must be very careful not miss any spots. Then part is ran thru an oven to fuse the powder into final coating. powder coating is the thickest and least duarable of finishes mentioned. I would not recommend powder coating due to the insulating effect.

I've never done ti coatings so I cannot comment on that. 

The reason most plating shops have a minimum charge is the labor to set up is the same for 1 piece as 25 pieces. Tipically a rack will hold 20-30 parts depending on how large. So when you run a load thru, it costs the same to run one part as 20. 

hope this has been useful information.


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## milkyspit (Jul 31, 2004)

*Re: Bare aluminum?*

Cy, that WAS useful! /ubbthreads/images/graemlins/blush.gif Thanks for the great primer (no pun intended) /ubbthreads/images/graemlins/wink.gif on protective treatments for aluminum. Your pros and cons plus personal opinions on each were great as well. Thank you sir!
/ubbthreads/images/graemlins/bowdown.gif


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## PEU (Jul 31, 2004)

*Re: Bare aluminum?*

is EN plating as hard as HA?

Pablo


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## FNinjaP90 (Jul 31, 2004)

*Re: Bare aluminum?*

So...about that tungsten carbide...anybody?


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## tvodrd (Jul 31, 2004)

*Re: Bare aluminum?*

Cy's explanation is in complete agreement with what I have been told/learned the hard way over the years. Aluminum oxide is a common abrasive used for some sandpapers and grinding wheels and is harder than EN. 

Tungsten carbide is a ceramic/metallic typically produced as very fine powders. These are combined with cobalt and other metal powders and pressed into shapes at very high pressure. The shapes are then sintered at very high temperatures in a furnace (vacuum?) to produce near net shape parts. After grinding to size, these parts become drills, milling cutters or clamped or brazed cutting inserts for cutting tools. It's a great deal harder and more wear resistant than HSS. I am unaware of it being available as a coating process.

I think a few TiN and TiCN treated lights have been done in H&M.

Larry


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## theepdinker (Jul 31, 2004)

*Re: Bare aluminum?*

I believe titanium nitride (TiN) is the coating Ninja had in mind.

Theepdinker


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## FNinjaP90 (Jul 31, 2004)

*Re: Bare aluminum?*

Yeah, but he was answering PEU's question.


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## KC2IXE (Jul 31, 2004)

*Re: Bare aluminum?*

As far as I know:
TiN (Titanium Nitride) = Gold color - ranging from coppery to bright gold (no idea what effects it) - VERY scratch resistant - no idea if it is conductive

TiAlN (Titanium AlumaNitride) - even harder, and is a dull silvery grey

There are one or 2 others in the same family - most of them were developed for cutting tools as a treatment to keep the chips from welding to or eroding the cutting edge. The farious types are either improvements, OR are ment for cutting materials that tend to combine with "Basic" TiN to wear the coating off FAST (remember that at industrial speeds, the area right behind the cutting edge on a tool can be RED hot) There's a saying, if your chips aren't blue, your not cutting fast enough


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## 4sevens (Jul 31, 2004)

*Re: Bare aluminum?*

cy: that was just an amazing writeup. I appreciate member of this forum who have "niche" pieces of knowledge that for most of the world is unappreciated. /ubbthreads/images/graemlins/smile.gif 

One question related to aluminum and oxidizing. You know the lights that have aluminum reflectors like the arc aa and aaa and ultra g - does the thin layer of oxidizing affect the reflective quality? also, i wonder if they treat it with something - or can it be treated to reflect better?


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## gadget_lover (Jul 31, 2004)

*Re: Bare aluminum?*

I turned a simple flood reflector for a 1 watt Luxeon. The finish was mirror bright. Two days later it was dull.

I re-polished it and gave it a shot of clear acrylic spray paint. It's not quite a mirror surface, but it's stayed quite reflective for 4 months.

Daniel


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## Rothrandir (Aug 1, 2004)

*Re: Bare aluminum?*

a couple months ago i chucked the head of my arc aaa into the lathe and went at it with some plastic polish (i was unsure if flitz metal polish would have a negative effect on the epoxy of the led, so i just used plastic polish on the whole thing)

it has remained quite reflective to this day... /ubbthreads/images/graemlins/icon3.gif
mutch shinier than when i got it...


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## FNinjaP90 (Aug 1, 2004)

*Re: Bare aluminum?*

My E2e laser had pretty big scratches on the reflector, so I tried some Blue Magic metal polish on it. It took the coating straight off! I'd be royally pissed if I did it to a normal SF reflector, but since my bezel was already drilled to accomodate the laser, it didn't matter.

In case anybody was wondering, if you take the coating off a SF reflector with metal polish, the material underneath it is a nice glossy olive-brown. Looks way better than the scratched reflector coating.

And Roth, good news! I got my laser fixed by Lasernerd! The culprit was a fried resistor.


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## Rothrandir (Aug 3, 2004)

*Re: Bare aluminum?*

hey, great news ninja! /ubbthreads/images/graemlins/grin.gif


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## 4sevens (Aug 4, 2004)

*Re: Bare aluminum?*

I just took a gutted head from an arc AA and some jewelers polish and polished it up. It's so reflective that I can see myself.

my question is this. what there a coating one there when it
was new? If not, what can I put on it to keep it from oxidizing?


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## milkyspit (Aug 4, 2004)

*Re: Bare aluminum?*

I am DEFINITELY no expert with polishes, but if memory serves, there are some silver polishes available that also leave a thin, clear film of some sort on the piece to slow down future tarnishing. They seem to work pretty well. Whether they work on aluminum, or even if there's a similar product specifically formulated for aluminum, I don't know.


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## FNinjaP90 (Aug 4, 2004)

*Re: Bare aluminum?*

Blue magic metal polish leaves a silicon film after it polishes. The stuff rubs off though. As long as its on an area that doesn't receive a lot of touching (Like an Arc AA reflector), it'll stay shiny for a good while.


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## Radiant (Aug 4, 2004)

*Re: Bare aluminum?*

Boeshield T-9 is good to keep aluminum from oxidixing. It stays on up to several hundred degrees and doesn't take away much shine. Developed by Boeing, so it has probably seen alot of aircraft aluminum.

http://www.amazon.com/exec/obidos/ASIN/B0000AXYBD/102-4164925-7204107


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## Arizona_Dan (Aug 5, 2004)

*Re: Bare aluminum?*

I've bought and used a clear spray lacquer that's sold in Home Depot (among others), the specific purpose of which is to protect brass from tarnishing, e.g. exterior brass door handles and outdoor light fixtures. It worked well for that purpose. Might work for some situations discussed here.


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## Stingray (Aug 5, 2004)

*Re: Bare aluminum?*

[ QUOTE ]
*theepdinker said:*
I believe titanium nitride (TiN) is the coating Ninja had in mind.

Theepdinker 

[/ QUOTE ]

Titanium nitride is often used on the forks of newer sportbikes, including certain Ninja models /ubbthreads/images/graemlins/grinser2.gif, as well as GSXR's, Ducati's etc. The forks are usually the first place on a sportbike to start corroding due to catching all the acidic guts of bugs and such, salt fron the ocean air etc, and the fact that some of us (like me) are too lazy to clean the bike every time we ride. The TiN finished forks seem to hold up quite a bit better than the others from my experience.


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## 4sevens (Sep 5, 2004)

*Re: Bare aluminum?*

Does the T-9 stuff leave a film?


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## NewsFlash (Sep 9, 2004)

*Re: Bare aluminum?*

How about an epoxy paint?

Aluma-Hyde II

It does have to cure. 

I've tried semi-gloss black after sandblasting and it looks pretty good. Seems to be pretty tough. /ubbthreads/images/graemlins/smile.gif

Also, you can always reapply it, and it all bonds together instead of layering up. /ubbthreads/images/graemlins/cool.gif


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## HarryN (Jan 31, 2005)

*Re: Bare aluminum?*

Hi - just reviving an old thread. I was playing around with some Al parts, and wanted to anodize them. I am pretty comfortable around acid baths, but my wife and kids are not, so I was looking for an alternative.

The goal, and what was achieved, is nominally similar to a type II anodize finish - certainly not as hard as HA III by any stretch, but required no acid baths.

Step 1 - clean, degrease, clean it again. I like to use 
- Gasoline 
- Paint grade alcohol (isopropanol)
- Strong detergent
- Alcohol rinse

At this stage the part looks and feels very clean. Now it is time to clean it again. I used
- Dishwater soap
- Lots of rinse in soft water
- Rinse in RO water
- Final rinse in drug store grade alcohol (isopropanol)
- Air / drip dry

During this stage of cleaning, I only handled the part with rubber gloves also cleaned the same way.

The "pseudo ano process"
- I put a screw with teflon tape into the threads I wanted to protect
- The part was placed in a kitchen cooking pan in hot soft water - near boiling, but not quite - no visible bubble formation.
- The screw was touching the bottom of the pan, but not the part. I used an insulated teflon coated wire (also precleaned) to hold the screw and part still.

This setup let the heat conduct up through the screw into the part. The part became the hotest spot in the pan, and all bubble formation occurred on the part.

(Before you ask, I was just guessing at this setup, and I have no idea exactly which parts of this are critical or way off - this was my first attempt. The only certainty is to make everything clean )

After 1 hour, the part had started to color a gray / light black color, but was not completely even. After 3 hours, the color was quite even, except that you could really see machine marks, even ones I had not seen previously.

The coating was still fairly soft, and scratched with a fingernail, so I decided to anneal it. I emptied out the pan, and placed the part directly in the dry pan bottom on the lowest burner setting (its an electric stove) for an hour.

A couple of interesting observations:
- Remarkably, my wife normally thinks my flashlight hobby is - well - a little /ubbthreads/images/graemlins/crazy.gif. She seemed to actually not mind me using her good cooking pans.
- The finish is not exceptionally hard, but it is in the same range as some black spray paints I have used, and there is no large mess.
- There are indications that this process could be improved without resorting to complex or hazardous chemicals.
- The finish is quite resistive - exceeds my DMM limit. I have no idea how leaky it is.

Any comments or suggestions are welcome.


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## milkyspit (Jan 31, 2005)

*Re: Bare aluminum?*

Harry, that sounds absolutely CRAZY! /ubbthreads/images/graemlins/crazy.gif

Just kidding. /ubbthreads/images/graemlins/wink.gif Actually, it makes intuitive sense, since anodizing is supposedly just accelerated oxidation of the aluminum. Can't believe your wide let you do all that with the cookware, though! /ubbthreads/images/graemlins/yellowlaugh.gif

What about that ceramic finish that Night-Ops or some such firm decided to use on one of their new lights? Is it really ceramic, or essentially just some sort of funky paint? And how tough might it be relative to HA3?


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## Arcoholic (Feb 1, 2005)

*Re: Bare aluminum?*

What about Teflon Coating.
I visited a shop recently to enquire about HA 3 and the guy laughed at me and said all you can get here ( east coast ) and need here for the rigs is teflon. He quoted really good prices about 20$ Can. per light., but the colors were limited to red, green and yellow. Tuff stuff though.


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## HarryN (Feb 2, 2005)

*Re: Bare aluminum?*

Hi Scott - I believe that the "Teflon" coating in cookware is anodizing and then impregnated with "Teflon". I suspect that SF does something similar based on the "feel" of their lights.

I did this experiment to deal with a simple and common home flashlight hobby person's dilema - one part that needs some kind of ano like finish. I will see if I can find someone with a dig camera to take a pic.

There are flame spraying and plasma spray processes that will coat just about any particulate coating material on just about anything else. I assume that the ceramic coated lights use this.

HA - III finish is not as common in the plating industry, but if you look in the yellow pages - there are shops. They will usually be ones that supply military spec. Peu has been doing some work in this area for his skinned light in the custom / homebuilts. Maybe he can comment.

Harry


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## greenLED (Feb 2, 2005)

*Re: Bare aluminum?*

What about that rubbery coat you dip tool handles in? Seems pretty durable
/ubbthreads/images/graemlins/icon3.gif


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## HarryN (Feb 2, 2005)

*Re: Bare aluminum?*

Hi Green - Good suggestion. The rubber - like coatings are good protection for home level use. In my particular case, I needed a coating that would be electrically insulating, and still allow for reasonable heat transfer (and somewhat decorative) 

I also had to get the coating down into some very small holes. There are relatively few methods of achieving all of these.


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## greenLED (Feb 2, 2005)

*Re: Bare aluminum?*

Yup, the rubbery stuff won't cover all your bases. I started thinking about it after some ppl suggested I use shrink-tubing for a light I'm trying to get for my brother (he needs to bite the light... go figure...).


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## PEU (Feb 2, 2005)

*Re: Bare aluminum?*

Let me chip in, I'm testing anno shops for the last month for my neoca bl project.

What I say here is what I learned from the shop owner and our fellow HarryN /ubbthreads/images/graemlins/smile.gif


HA3 process depends mainly on the temperature of the bath and the aluminum alloy.

When I started sending samples to the shop, I didn't know the alloy of the AL, I tought it was 6061, but it wasnt... /ubbthreads/images/graemlins/banghead.gif 

It was 2005 which hard anodizes fine to the eye, but when you scratch it with a xacto knife the HA3 layer dissapears. Color rendering on this alloy is very nice if you dont want it hard.

Enter the proper alloys: 6262 then 6061 and then 7075 in that order and tempered if possible.

The results are night and day compared to 2005 AL, you cant scratch any of them unless you put A LOT of pressure on the cut, and if you use a thin knife you may end breaking the tip due to excesive force applied before denting the HA3.

With a stirred bath at around zero celcius and 3 hours, you get around 50microns HA3 layer which is excellent. The more you leave them on the stirred bath the thicker it gets, but is more difficult by the hour, why?, because you need to start increasing the current and risking burning the part due to excesive current (it happened to one of my samples / photos in the neoca bl preorder thread)

One important thing I almost forgot, avoid sharp edges when doing anodizing, and this includes HA3, why?, because the anodized layer grows perpendicular to the AL, so at the edges there will be no union. 
Take a look at your HA3 ligths at the edges and you will see what I mean.
The solution? simple as always, be sure to round all the corners. A 0.25mm radius does the trick wonderfully.

Last samples I sent (ready tomorrow) were 6262 AL, one natural, 2 black and one unprocessed to measure thickness by comparation on a flat surface.

Hope this helps understand the process a little bit more...


Pablo


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## milkyspit (Feb 3, 2005)

*Re: Bare aluminum?*

PEU, that's one heck of a load of information! /ubbthreads/images/graemlins/ohgeez.gif

THANKS MAN! /ubbthreads/images/graemlins/clap.gif


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## PEU (Feb 3, 2005)

*Re: Bare aluminum?*

Thanks Scott /ubbthreads/images/graemlins/blush.gif

I just came from the anno shop again, the samples I was expecting didn't made the quality test /ubbthreads/images/graemlins/smile.gif They put my samples along another job but it was interrupted early because the operator was afraid of burning the main batch.

Anyway we tested the thickness of the Ha3 (natural and black) and it wasnt scratchable without aplying some force, but when you were decided, it scratched, so its a failure.

The thicknes was measured and it was 20 microns, and to be really tough you need at least the double.

I forgot to post one thing I noticed yesterday and that is the coloring of the HA3.

Coloring matching of hard anodized parts its a tricky business because dyeing is done over the ha3 natural and not at the same time. In fact coloring is a completelly different process from the HA3.

So for example, take an ARC AAA LE which is ha3 natural and is opaque olive color, after that finish you can put any color and do the dyeing but the color wont be the same as if you put it over a white sheet. Thats why HA3 colors tend to be opaque and not shinny.

The anno owner explained the coloring process in a simple way that I'll try to translate and keep it simple:

The anno layer is like hairs that grow perpendicular to the aluminum, and the dyeing process put dye particles in between those hairs, and when the coloring process is finished by sealing the part, those particles mixed with the color of the ha3 natural gives you the final color.

Next visit to the shop is monday/tuesday /ubbthreads/images/graemlins/grin.gif if you have any question, I may ask them.


Pablo


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## sween1911 (Feb 3, 2005)

*Re: Bare aluminum?*

WOW. Glad I found this thread. I have a tired Surefire E1 (not Elite) in gunmetal grey. (WHY oh WHY did I GET THIS COLOR???) After carrying it in my pocket for a year or so, the finish wore off. I disassembled it and hit it with black Rustoleum appliance-epoxy spray paint. The finish is wearing off in record time /ubbthreads/images/graemlins/frown.gif BUT I have tried this same paint with clear Krylon on top on a knife clip and it looks okay. 

I was going to inquire about how to get a light re-anod'ed, but this thread is great reading! Hafta check in with shops near me and get a feel for pricing. /ubbthreads/images/graemlins/smile.gif


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## mrg3013 (Feb 4, 2005)

*Re: Bare aluminum?*

out of curiousity, does anyone know what they use to coat cookware like Calphalon(sp?) with?


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## R-R (May 24, 2008)

I just realized that you can scratch a tungsten carbide ring by unscrewing and L1D-CE Q5's top ... oops!

Damn Al2O3 at Moh 9


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## will (May 24, 2008)

*Re: Bare aluminum?*



mrg3013 said:


> out of curiousity, does anyone know what they use to coat cookware like Calphalon(sp?) with?



I had a fry pan - expensive - and not dishwasher safe. The outside is anodize. It looked like junk after a few trips through the dishwasher. The inside is teflon coated that got scratched. I returned it under their lifetime warranty, they returned it to me stating customer misuse.

( I just realized how old the original thread is )


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## R-R (May 24, 2008)

hehe yeah sorry for reviving old zombie threads... I'll blame the search engine for this (just wanted to warn people who have tungsten & hard anodized things)


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## Burgess (Mar 18, 2009)

This is STILL a very interesting thread !


:wave:
_


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## will (Mar 18, 2009)

I have refinished Maglites in both Powder Coat and Electroless Nickle 
Powder is much tougher than any paint, but not as hard as anodize. It is a thick coating. The Maglites pictured here are masked by all the threaded areas. I leave the original anodize alone. The knurled areas are somewhat filled in with the powder, too much and the knurled area is filled in, too little and you get shadows. The main advantage that powder offers is a greater choice of colors. 

Nickle plating offers a very thin coating, the ability to have a brushed finish, a polished finish. Threaded areas do not have to be masked off and can be plated with no electrical problems. I have been dealing with a shop that has a 3 day turnaround, ( at least that is what it was a year ago ) 

Some old threads are still worthwhile


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## greenLED (Mar 18, 2009)

FWIW, I have one of will's nickle-plated minimags... purrrdy!


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## milkyspit (May 6, 2009)

This may be an old thread, but it's my thread! :nana:

More importantly, it is hopefully a useful thread... I know it's been a learning experience for me.

Question: how does the typical powder coat compare with things like Duracoat and similar? In some respects those would seem about the same, though I suspect they're somewhat different? How... just harder?
:thinking:


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## LukeA (May 6, 2009)

milkyspit said:


> This may be an old thread, but it's my thread! :nana:
> 
> More importantly, it is hopefully a useful thread... I know it's been a learning experience for me.
> 
> ...



You can Duracoat/GunKote over threads successfully. Try that with powdercoat. The wear cycles per mil is much better with the thin polymer coatings but there are typically many fewer mils of thickness, although you can apply those coatings as thickly as you want.

Now, the durability and lubricity of GunKote/Duracoat is nothing to be scoffed at. I applied a thick (~.003in) layer of GunKote to the striker plate on my storm door's frame, and after six weeks of use, it shows zero wear. No scratches, no scuffs, no difference from the moment it came out of the oven.


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## will (May 6, 2009)

Powder Coat is a thick coating, don't use it on threads. It is much stronger than regular paint. It is used on everything from Motorcycle frames to kitchen appliances. I don't know how that would compare to duracoat.


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