# how do i remove anodize?



## TrevorNasko (Jun 4, 2002)

i wish to remove the ano on some of my lights. how can this be done without abrasive tools?


----------



## DonL (Jun 4, 2002)

The old mountain biker's trick after "3D Violet" (*gack*) passed out of fashion vogue. I don't know how effective such a thing will be on the hard-anodized coatings used on some lights. This works for the more common decorative anodizing.

Oven cleaner, like Easy-Off. It's a mild sodium hydroxide solution that will strip through the anodized layer to the substrate in a sufficient amount of time.

*My caution and disclaimer:* I used to work with stronger NaOH solutions for cleaning aluminum vacuum deposition "overspray" from production equipment. I'd recommend wearing safety glasses or goggles, and good rubber gloves. HaOH is another term for caustic lye. You don't want to get this stuff all over you. If so, rinse quickly, rinse very well, and rinse again. In case of excessive contact, acetic acid (vinegar) can be used to help "balance" the pH of the NaOH and make it less harmful. Then, as mentioned, rinse. Alot. 

Remove springs, switches, seals, lenses. Excessive exposure of aluminum to NaOH can have adverse effects on the aluminum, so go easy, spray-and-scrub, and rinse thoroughly. Take your time and repeated applications rather than to try to strip it all off at once.

That's just my experience and comments. Others may have other views or experiences.


----------



## Slick (Jun 5, 2002)

Eagle 1 Mag Wheel Cleaner... Get the spray-on kind intended for use on sand-cast style aluminum mags. It's an acid so you'll need to use some caution - so don't say I didn't warn ya.

This is a"custom hot rodder's trick" we stumbled on to for removing the red & blue annodize from high performance AN fuel fittings. Once the annodize is stripped, the parts can easily be polished to a "chrome-like" finish. We would soak parts for only about 15 - 20 minutes, so keep your eye on your parts. You may need to use a dropper and some wax to mask off areas if submersing the whole piece isn't an option.


----------



## DonL (Jun 5, 2002)

LOL! From base to acid. That seems to cover pretty much the whole pH scale, doesn't it?


----------



## Darell (Jun 5, 2002)

Reminds me of a stupid commercial I saw recently. They were mentioning how most general-purpose cleaners have a pH of between drain cleaner (typically acid) and bleach (obviously base). Well duh. water falls right in that catagory too! Damn near everything falls between acid and base





Funny that they never mentioned the pH of their product. They just warn you of the hazzards of pruducts around pH 7


----------



## TrevorNasko (Jun 5, 2002)

so what do i do to take care of a e2?


----------



## sunspot (Jun 5, 2002)

Send an email to Silviron. He posted somewhere about a solution to remove anodizing. Or do a search for anodize&silviron.


----------



## Silviron (Jun 5, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by phred:
*Send an email to Silveron. He posted somewhere about a solution to remove anodizing. Or do a search for anodize&silveron.*<HR></BLOCKQUOTE>

I did? Can't remember that. I had a few posts about anodizing titanium in the ARC forum, but they were more on how to apply than to remove.

I do know of a solution that will remove TITANIUM anodizing (not nitriding) but it is really nasty- 70% Nitric and 30% Hydrofluoric acid- Concentrated Nitric is bad enough, but Hydrofluoric is really nasty and not something for non-professionals to mess with.

That solution might remove aluminum oxide anodizing too, but I don't have any here to test it with.

If the suggestions mentioned by others above work, that would be the best way.

If you have a friend with a sandblaster, I'd recommend using that with about 220 grit Silicon Carbide abrasive.

I just had to remove some anodizing from ARC LS battery holders for JonSidneyB's C & D cell holders, and just used diamond bits and ground it off- but that requires a lot of refinishing work and will destroy any knurling etc.


----------



## sunspot (Jun 5, 2002)

Silviron. Sorry if I went the wrong direction. Coulda sworn it was you. I do remember some post about it. I was going to recommend bead blasting. Many knife finishers offer this service.


----------



## Silviron (Jun 5, 2002)

I suppose it could have been me; but if it was, I was drunk and made it up!





Haven't had a lot of experience with anodizing aluminum; Mostly have worked with Titanium, Tantalum and Niobium in that respect. And the times I have had to remove Aluminum anodizing, I either just ground it off or sand-blasted if I had a blaster handy.


----------



## txwest (Jun 5, 2002)

Most of the machine shops that rebuild cylinder heads will have a bead blaster. They use it for getting the carbon off valves. If it's a small shop & you talk to the guy in charge right, he'll probably let you use it. TX


----------



## lightlover (Jun 6, 2002)

I had an E2 and a Mag 3D sandblasted by a friendly local glassworker. He used 220 grade AlOx and it only took the machine seconds to do it.

I did this on an E2 in GM finish, and polished it back to the Aluminium. 
The effect after sandblasting gives you a smooth but sugar-coated look, like "frosted Aluminium", very pretty. That effect is because it's a texture, probably with millions of small raised areas where the 220 grade sand has left "peaks" or raised bits of Aluminium. Unfortunately, it shows any contact, (even by a fingernail) as shiny scratches.

That surface can be polished - I used "Solvol Autosol" a quite aggressive polish. You then get a matte grey effect, which looks like bead-blasting. But, it still scratches *quite* easily (because it must retain some peaks ?).

If you then hand-sand it down, using ultrafine jewellers paper, you will cut out some tiny details, like the "sharp" microscopic edges of the knurling, but it just looks like a patina, no real loss. I've thought that the E2 treated this way looks like a 1940's lighter. Sanding after sandblasting before you polish up gives a shiny finish. 

I also had a Mag 3D sandblasted - I wish I'd tried the chemical removal of the anodising instead. Polishing something that size back to a mirror finish is hard hard work.

lightlover


----------



## txwest (Jun 6, 2002)

Unless you put some kind of sealer on it, you'll have other problems. The bare aluminum will get finger prints & stains. You could get more than you bargined for when you strip the finish. TX


----------



## K-T (Jun 8, 2002)

Jahn, could you post any picture of that E2? I would love to know how/what it looks like.

Klaus.


----------



## lightlover (Jun 8, 2002)

Klaus, 
Graham asked about that too. I've got to get my friend to do a digital photo of it, and then I will post it.

It isn't a shockingly different appearance or anything special (but I like it).

TX, it certainly isn't as practical and tough as the HA3, but in my experience Aluminium wears quite well. It automatically anodises itself, so if kept out of adverse conditions like alloy wheels suffer, shouldn't actually corrode.

I think if I just keep it clean and polish it occassionally it will be OK. There aren't any fingermarks on it as yet.

lightlover


----------



## McGizmo (Jun 8, 2002)

Jahn,
You might want to get some anhydrous lanolin and rub that into the bare aluminimum. There's some stuff here in the states called Lanocote which is a specially blended lanolin. The stuff keeps aluminum from oxidizing and corroding. It is truely amazing. Clean the metal first and then put some on and rubb off all the excess. I had a black anodized mast that was starting to show it's 12 year age and I put some lanocote on it and it looked new. I sold the boat a year later but the mast still looked great. And you thought sheep were only good for one thing


----------



## lightlover (Jun 10, 2002)

Sheeps - you'll have to ask Welsh Chris M about that ...... 

Thanks for the advice Don, I've never heard of that stuff. Does it leave any residue - any idea how it works ?

Incidentally, the Inova X5 with the Titanium finish - that's just coloured up common anodising isn't it, not actually a Ti coating ? That's next on my re-finishing list.

lightlover


----------



## McGizmo (Jun 10, 2002)

Jahn,
See: Lanocote
As I understnd it, plain old anhydrous lanolin will work near as well but may not hang in there as long, especially in salt water which isn't an issue in your case. Lanocote is like a very hard axle grease at 60 F and like melted butter at 100 F (I don't do C, sorry) Any excess can be wiped off. If you do a google on anhydrous lanolin, you'll see that you want some on your skin any way 

The Ti on the Inova is just a color of anodize. Most Ti coating or plating i've seen is gold in color and prettty common now on cutting tools like drill bits, end mills and carbide inserts.

I get a kick out of how many items are now made to look like they are titanium. I think it would be cool to make a Ti part and finish it off as simulated walnut grain




I new a guy who popped for about $80,000 on a super high tech carbon fiber mast for a classic wood sailboat. He then paid a real artist, a few grand to paint the mast to look like spruce; down to scarf joints,knott holes and wood plugs. It looked like wood from any distance but the dry rot fungus was sorely disappointed.


----------



## Silviron (Jun 10, 2002)

The Gold coating you see on tools, drill bits etc. is not anodizing or plating strictly speaking- It is titanium nitride, and is deposited by a completely different process- 

PVD: (Physical Vapor Deposition).
Usually done in a vacuum or an inert atmosphere, an electrode of the material is vaproized / ionized with an electric arc, attracted to the object by an opposite electrical polarity. An older term that may be used to describe this process is "sputtering".

Titanium (Niobium & Tantalum too) may be directly anodized to a gold color easily, but it is neither as bright or durable as Titanium Nitriding.


----------



## lightlover (Jun 12, 2002)

Going back to Aloom'num (see, I can spell it the American way).

If it self-anodises, why do people complain that it leaves black marks on your hands if touched ? Personally, I've never noticed that.

Don, if Lanocote turns to a liquid at 100 deg. F, it won't be much use on an E2 due to the heat produced. It'd work OK on a stripped Mag OK though.

lightlover


----------



## McGizmo (Jun 12, 2002)

Jahn,

You might be right about the Lanocote but we're talking about a very thin coating that is left, maybe at close to molecular level? All I know is that a black aluminum spar can get pretty darn hot and although the viscousity may get very thin, oils and such seem to stay on hot metal surfaces without much trouble (machinery, frying pans,etc.) My friend in Hawaii had one of those rectangular 500 watt quartz halo flood lights that was on a post 15' from the ocean. One year while visiting, he asked me if I could get it to work. The steel screws were "welded" into the cast AL body of the fixture and the thing was shot. I cut it off and replaced it with a new fixture. I coated all the fasteners and conduit connectors with Lanocote prior to assembly. A couple of years later, on my anual visit, my friend told me the light had died again and asked me to investigate. I took one look at the light and laughed! I t was half vull of water! The steel screw heads were covered in rust but for the hell of it, I took a philips driver to them and they backed out with no effort! No white Al oxide in or around the screw holes. I drilled a big drain hole in the botttom of the fixture and replaced the bulb and the darn thing was still working a year later when my friend sold the house.I reckon that that fixture saw some nasty storms and plenty of heat. I am sure that the Lanocote can fail, I just haven't run across or heard of a case yet. Perhaps a bare A, SF could be that case....


----------



## lightlover (Jun 12, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by McGizmo:
*... close to molecular level ...*<HR></BLOCKQUOTE>

Hey, I like the way that sounds ! 

When I put things in the freezer for close interference fit purposes, I say that I'm cryo-engineering ...... 
(Y'know, alongside the ice-cream !)

Now, I'm working at close to molecular level too - wait till my friends hear about this !!

Don, I contacted them, and they are sending me some Lanocote.
Will report back to the board in due course.

lightlover, Engineering Division.


----------



## McGizmo (Jun 12, 2002)

Jahn,
Every morning, after a few ciggs and cups of mud, I retire to the lou for creative bio- sculpting. (Although I have been accused of cloning in this process) Think Craig's toi-toi search engine will sniff this one out?


----------



## DonL (Jun 12, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Silviron:
*The Gold coating you see on tools, drill bits etc. is not anodizing or plating strictly speaking- It is titanium nitride, and is deposited by a completely different process- 

PVD: (Physical Vapor Deposition).
Usually done in a vacuum or an inert atmosphere, an electrode of the material is vaproized / ionized with an electric arc, attracted to the object by an opposite electrical polarity. An older term that may be used to describe this process is "sputtering".
*<HR></BLOCKQUOTE> 

Ooh, ooh, ooh! Mr. Kotter!

Hey, I know some of this stuff!





Jahn, you've told me in our e-mails to toss stuff out that I may have some knowledge of to share with the class.

This is your fault.








For several years I did vacuum metallizing and thin-film sputtering (that's what we called it then), using aluminum, silver, and occaisionally nickel in the VM, and nickel and cobalt in the TFS. The layers we were putting down were in the range of 5 up to ~20 angstroms (Ǻ, one ten-billionth or 10X10^(-10)) thick. Vacuum levels were 7X10^(-5) to 6X10^(-6)torr, or mm. These were used mostly as passive/reflective substates, where _some_ light can get through, and some is reflected, and as a plating substrate for stamper build-ups on photoresist-coated glass. 

Sounds real tech weenie until you coat up a carpenter ant to get a good shot under a scanning electron microscope at 200X.





The "welding" that Don is referring to is often called "galvanic corrosion". It happens often when two dissimilar metals are in very close proximity to each other in a solution that acts as an electrolyte. (Sea water is a great example.) A similar effect is what causes the ends of automobile battery cables to become grunged up with that whitish-green schmutz.

The two metals, encouraged by the electrolytic medium, start tossing around ions in an anodic/cathodic (cathartic?) manner, essentially merging on a molecular or atomic level. The steel screws and bolts and the aluminum light fixture is a great example. 

Another good example is often steel bicycle frames with aluminum seatposts ridden in mud, rain, and sometimes slushy streets, where the post nearly becomes fused into the frame and needs to be _very_ forcably removed. I've seen several instances in which the seatpost is ultimately clamped down in a bench vise, and the entire frame is put into use to create enough leverage to break the two apart. 

Oils, greases, anti-sieze, etc., act as an insulator that reduces or negates that galvanic effect. Since it happens on a molecular and atomic level, not a very thick layer is needed to prevent that white powedery ick.

Well, if anyone's still awake, remember that this was Jahn's fault.



I hope I didn't confuse the heck out of anyone, I'm a bit out of practice and rusty on some of this stuff. 

Oh, and Jahn, next time you're poking around in your freezer, say hi to Walt Disney for me, okay?


----------



## Darell (Jun 12, 2002)

I'm always willing to stay up late for an interesting lesson, Dr. Don. Thanks for the great info. But I'm still confused: What does this have to do with McGizmo's "bio-sculpting? Is it all part of his personal "galvanic corrosion?" Sounds painful, really.

(Note to Jahn - since this is your fault, apparently: I don't think that anybody who doesn't _want_ to get this actually will think about it long enough to be offended)


----------



## DonL (Jun 13, 2002)

darrell, my best guess is that the by-products of McGizmo's bio-sculpting has potential to be highly electrolytic, thus rapidifying (?) the corrosion process. 

Especially after Taco Bell...


----------



## McGizmo (Jun 13, 2002)

Process time verification: see corn kernals


----------



## lightlover (Jun 16, 2002)

Well, I managed to remove the Titanium coloured anodising on my Inova X5. I'm very happy with the results: it looks beautiful, a lovely white-silver and mirror like. I didn't realise previously that it was so smoothly finished. (And KT, it's quite like Stainless Steel ... )

If you like the colour of Aluminium better, it's worth trying. But, first get parental permission if applicable. 

CAUTION - Caustic Soda is one of the most dangerous chemicals you can buy without restrictions. It is EXTREMELY reactive and DANGEROUS - even if used correctly. ALWAYS read and understand the instructions for mixing it CAREFULLY, and follow them. 
For instance, the label should say that you must always add it to water, never the other way around. If you do it wrongly, it's actually explosive and you will be very sorry indeed.
Sprinkle it slowly into the water, or it can form a hard paste which will have a very much stronger effect than the rest of the solution. Use protective gloves and eyewear, do it in a sink with rinsing water there, ready. Do not put a wet spoon into a container full of caustic, and put the lid back on straightaway.

To protect the LED's I used wax to fill around and over them. The LED's are just very slightly inset, so protect them with a lot of wax. Because I had covered all that face with wax, I removed the anodising there with jewellers paper, quite easily. If sanding the metal, beware scratching the LED's. 
To protect the O ring and the inside of the body, I put the body-only into the freezer to fill with dense cold air, so as to try and provide positive pressure when the head (left at room temperature) was put back on again. The threads and O ring were smothered with Nye-Gel so as to try and leave no pathway for the Caustic solution to enter after I'd screwed the head on. Just wipe off the excess once it's screwed on tightly.

For the alkali solution, I used a tablespoonful of Caustic Soda to a pint of water. 
(About 40ml by volume to 500ml water ?)
Using a tall glass, so that I could see what was happening, I immersed the whole X5, and watched as the anodising simply began to disappear, starting after 20 seconds or so. Remove, rinse, examine and return. A total of about one minute of immersion left me with a clear Aluminium torch with a few "rustmarks" left in the grooves. The anodising was being removed somewhat unevenly. I didn't want to overdo it and be left with a caustic marked finish, so decided to polish it and try again later if necessary. Using "Solvol Autosol", a quite sharp polish, it became clear that a little more time in the solution couldn't make it worse but might improve it. Another <25 seconds, and that time, there were just a few small "rustmarks" left.
It polished up perfectly, no marks visible, except very faintly under 3x magnification.

In fact, I was so pleased with it, I got carried away and convinced myself it had a brighter output too !!
I always liked the style of the X5 and to me it looks so much better now.

Actually, although the LED's are recessed, it may be that over a long time of EDC they had become dirty, and the cleaning I did might have made a change. Not something that ever occurred to me before - if a LED is exposed, it probably gets "cleaned by carry". But with recessed LED's and no lens, any thing that got onto then would not be rubbed off. 

Also, even though the LED's are very closely fitted, there is quite a deep gap around them, and lint, dust etc. could also have been stuck there, blocking some of the output.

Jahn


----------



## Empath (Jun 16, 2002)

Jahn,
By wax, are you talking about paraffin over the LED? How did you remove the wax?


----------



## sunspot (Jun 16, 2002)

A wax remover can be bought in most craft stores. Empath, paraffin in the UK is what the US calls kerosene.;> )


----------



## lightlover (Jun 16, 2002)

phred, you're up early for a Sunday ain'tcha ?

Yes, we're two cultures separated by the same language. But it was Paraffin Wax. It removed fine, just using a cocktail stick run around the individual LED's - came out easily.
I suppose to make certain that none was left behind, you could pack around each LED with some cotton wool or similar stuff.

Jahn


----------



## sunspot (Jun 16, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by lightlover:
*phred, you're up early for a Sunday ain'tcha ? Jahn*<HR></BLOCKQUOTE> Yep. Up before 05:00 CDT, 11:00 GMT.
Odd. I just saw your previous post and remarked to my wife "Look, Jahn is up early".
Anywho, congrats on the anodize removal. Sounds like a fine job and quick also. I now want to copycat you. How is caustic soda sold? Is there a brand name for it? Oh, where to look. BTW, my wife has a SF 6P in clear anodize. Very pretty it is.
Cheers


----------



## Empath (Jun 16, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by phred:
[QBHow is caustic soda sold? Is there a brand name for it? [/QB]<HR></BLOCKQUOTE>

We sell it here under the name "lye". It use to be more familiar when people made homemade soap, and is often an ingredient in drain cleaners. It's nasty stuff, and highly alkaline. I think the caustic soda usually refers to sodium hydroxide, but lye can be either sodium hydroxide or potassium hydroxide. Either way, don't handle it casually.


----------



## sunspot (Jun 16, 2002)

Thanks Empath. I know about lye and have used it many times. Caution IS the word here.


----------



## lightlover (Jun 17, 2002)

actually phred, that was me going to bed late !!

(Honest - I'd never get up early in the morning if I could help it. But I'd worked through the night, y'see.)

I thought that Caustic Soda was a name universally used - but whatever you call it, it is 98% Sodium Hydroxide.

If you're going to do your Inova like that, just remember to keep testing the progress, and sponge off any loose bits of anodising while rinsing, to make your progress more readily visible.

Doing a black anodised Mag is spectacular - the anodising comes off very easily, colouring the DANGEROUS solution very black indeed.

Jahn


----------

