Hand Polishing My Flashlight?

[Noctis]

Ever since I got my Elektrolumens Decree XP-G today, I've been contemplating stripping off the anodized black coating :devil: and polishing it by hand to a mirror finish.

Info page for reference:
http://elektrolumens.com/DeCree/DeCree-XPG.html

The first problem is actually taking off the hard anodizing. Now first off, I don't exactly have a shop with any level of basic tools, so bear with me.

This is the option that is readily available to me and to me has the best chance of success. I don't have a true buffing wheel, however I do happen to have a buffing wheel "attachment" on my hand drill. I have a number of the typical abrasives that are mixed inside wax sticks used for polishing steel. While I'm not 100% sure that the coating will be removed, I figure since these abrasives are meant to polish STEEL, I stand a pretty good chance.

My other option would be to use sandpaper and sandpaper-like abrasives to strip the coating off. In the past, I used 60 grit sandpaper to strip the black coating from my Benchmade knife, and then used finer abrasives to polish it to a mirror finish. Though because I used such a coarse grit and I had no experience in doing such a thing before, the scratch marks are still fairly obvious on the blade, despite the fact that I can more or less use it as a mirror. Also been wondering if I should crisscross(going up and down with one grit, then left and right with the next) to keep track of the sanding progress, or if I should stick with just one direction.

The main issue with both of these methods would be the possibility that the coating won't be completely removed from the grip on the tailcap. Having shiny aluminum with bits of black mixed in would make it look fugly.

I figure the best method for that part would be to use a chemical to strip it off. For convenience sake I would prefer something that would be available in your local supermarket. I have a bottle of Brasso, but I somehow doubt that it would reach the deepest parts of the grip. If push comes to shove I can simply leave the tailcap black.


As for why I would do this as opposed to sending it to someone else... well, I'm not 100% sure what hobbies I would like, but I'm pretty sure working with my hands is definitely one of them.:twothumbs

 

[Th232]

Also been wondering if I should crisscross(going up and down with one grit, then left and right with the next) to keep track of the sanding progress, or if I should stick with just one direction.

If you're going to do it with sandpaper or other abrasives, you'll have to crisscross. Doing it one direction won't get you anywhere near a mirror polish. For a mirror polish with sandpaper, you sand it in one direction until (in your case) the anodising is removed. Then sand at 90 deg to the original direction until you've completely removed the original scratches. Sand in the original direction until the new scratches... you get the drift. Essentially you keep making finer and finer scratches until they're no longer visible to the naked eye.

That said, I'd go with some kind of chemical stripping, since as you say, the anodising won't be completely removed in the knurled section of the tailcap. Unless you keep sanding until you've completely removed the knurling, and I suspect you don't want to do that.

 

[Noctis]

If you're going to do it with sandpaper or other abrasives, you'll have to crisscross. Doing it one direction won't get you anywhere near a mirror polish. For a mirror polish with sandpaper, you sand it in one direction until (in your case) the anodising is removed. Then sand at 90 deg to the original direction until you've completely removed the original scratches. Sand in the original direction until the new scratches... you get the drift. Essentially you keep making finer and finer scratches until they're no longer visible to the naked eye.

That said, I'd go with some kind of chemical stripping, since as you say, the anodising won't be completely removed in the knurled section of the tailcap. Unless you keep sanding until you've completely removed the knurling, and I suspect you don't want to do that.

I suspect that it would take quite a while to remove the anodizing by hand. I'm hoping the buffing wheel would be up to the job of stripping the coating off.

I'm entertaining the idea of buying a small "true" buffing wheel and doing most of the job on that, and finishing up with the finest grit sandpaper.

While I did say I enjoy working with my hands, I spent a week polishing that damn knife blade alone, and it still doesn't look completely smooth.

No need to kill myself over just that right? :devil:

The problem is how to tell when the scratch lines are gone when you're on your 3rd finest abrasives and the thing already looks like a foggy mirror? :candle:

Also, which chemical do I use? Someone mentioned using Easyoff oven cleaner, but I would have to be sure it's strong enough to strip enough of it off so that it doesn't look black.

 

[^Gurthang]

To strip ano off you need sodium hydroxide solution [drano crystals] but be VERY careful when handling it is NASTY stuff. You'll want to make a working solution and let it cool before you use it, otherwise it can remove more than the anodization....

Here's a DIY site for anodizing that covers stripping quite well.

http://astro.neutral.org/anodise.shtml

Best to suspend the parts from wire and dunk in the solution. Have plenty of fresh water at hand. You may need to dunk the parts several times [short] to get all the anodizing off. For polishing I'll recommend Caswells. They supply LOTS of different metal finishing products.

http://www.caswellplating.com/

I've used their polishing rouge for alum wheels. They stock everything you could possibly want [other than someone to do the work for you].

 

[Noctis]

I think I'll pass on the sodium hydroxide. There doesn't seem to be clear-cut instructions on how much to use, mixing it, how long to leave it in there, proper disposal, proper container to use, and there also seems to be a warning that leaving it in too long will cause the parts to mismatch. I'll probably just leave the coating on the tailcap, or cover the knurling in masking tape while I strip the rest of the coating away, so that it looks like just a black stripe(not sure if it'll look good though).

Also not sure I want to wait a week for delivery of the polishing rouges. I somewhat doubt that those are much different than the ones available at the local Sears store.

 

[RepProdigious]

Ive stripped anodizing layers from various parts (iPods and such) in the past, and Crofty works perfectly fine for this purpose! Just make sure you remove all the gunk and grease from the surface beforehand or those parts will strip slower (think dishwasher)!

Also keep in mind that any exposed aluminium surface that has to keep right dimensions/surface treatment (think threads and such) will be severely altered by this treatment. You're best off painting them with simple hobby enamel paint (humbrol/revell) for protection and removing the paint afterwards with any 'female' cleaning agent or paint remover.

Also, unlike suggested, for me this chemical process works best at elevated temperatures but do keep an eye on it, you dont want it to go too far over 60 celcius or so. Oh, and DO wear protective eyewear, gloves and clothing you can afford to lose, THIS IS NOT A LUXURY OPTION, that crofty stuff is nasty!!

 

[Noctis]

If I understand correctly, this stuff is more or less just drain cleaner right?

Also curious if I can use renaissance wax to protect the threads, or would it be dangerous to mix petroleum products with this? I'm mostly just using this for the tailcap, so I'd rather not buy paint just for this. Besides which, we're short on hobby shops here.

 

[RepProdigious]

If I understand correctly, this stuff is more or less just drain cleaner right?

Also curious if I can use renaissance wax to protect the threads, or would it be dangerous to mix petroleum products with this? I'm mostly just using this for the tailcap, so I'd rather not buy paint just for this. Besides which, we're short on hobby shops here.

I dont know if any wax or alike would work, but i wouldn't risk it (a small hole in the wax makes a big hole in the aluminium)..... I do think you'll get good results with nail-polish (just steal some from your wife) but again, no guarantees. First give it a try on some aluminium (anodized or not) you can afford to lose, this also gives you a bit of a 'feel' for what to expect from the chemical reaction and such so you wont freak out when your mixture all of a sudden starts to boil (bad thing). You do have a good thermometer?

[edit] And yes, its drain-cleaner but i believe not all drain cleaner is the same, just get the one with the most warnings on the label [/edit]

 

[^Gurthang]

-10 on wax / grease to protect threads, sod. hydroxide dissolves grease, you would just contaminate the stripping solution. Seal threads w/ nail polish or teflon tape.

Try 2 TBSP of crystals to 1 Qt. of water to start. The ano will fizz as it reacts. Just dip the part in for 30 sec. to start, rinse, wipe and inspect. Even poor anodization will take several dips to strip off the finish while good ano is tough and may require a more concentrated solution to remove the finish. Always use gloves /goggles to protect yourself.

I will mention another stripping method you could try. Bead blasting. Fast, simple, easier to mask off threading. A light bead blast finish would take a bit more time to smooth up for a mirror finish but much safer than chem. stripping.

 

[thebeans]

Wow this is weird. I have a DeCree coming soon, hopefully tomorrow. And I stripped the black ano off a different light yesterday.

The light was shiny black ano like a Surefire 6P yesterday morning. An hour or so later it looked like this:

Then after a very little bit of hand polishing with just a rag and some metal polish and reassembly it looks like this:

I will likely polish it some more later. I personally don't like the super shiny chrome look but some people like that look. You just keep polishing till it is as shiny as you like. I don't think I would try to remove ano with a buffing wheel though. Probably won't work well, esp with the knurling on the tailcap. Chemical stripping will likely work much better as long as you can get the light all the way apart. I think I remember reading a comment by Wayne in some thread that the tail cap on the DeCree needed to remain anodized. Not sure if that was to do with the functioning of the switch or what.

 

[RepProdigious]

That looks about right.... Nice job!

If you do decide to go full polished and don't want to 'invest' in polishing tools you can get great results with a 'handjob' if you buy some Belgom Alu polish (available at your local automotive specialist). Just put some (pea-sized blob) on a piece of cloth and span the cloth over the sides of an old credit-card to polish the insides of nooks and crannies first, you can polish the big and easy surfaces later on (if you do this the other way around you risk damaging the big surfaces and you will have to do them over). Best to use a white cloth, this way you can see how much material you've taken off. If the cloth gets deep-dark grey its time to get a new cloth and some new Belgom and continue!

 

[Noctis]

I will likely polish it some more later. I personally don't like the super shiny chrome look but some people like that look. You just keep polishing till it is as shiny as you like. I don't think I would try to remove ano with a buffing wheel though. Probably won't work well, esp with the knurling on the tailcap. Chemical stripping will likely work much better as long as you can get the light all the way apart. I think I remember reading a comment by Wayne in some thread that the tail cap on the DeCree needed to remain anodized. Not sure if that was to do with the functioning of the switch or what.

Well it seemed to work just fine on a cheapy light with anodizing. Might be a bit harder to remove the anodizing off a higher quality light though. Still, I think what's important is that the hardness of the abrasive is higher than the hardness of the anodized aluminum.

I seem to remember hearing something similar about the tailcap, but I can't seem to find that post.

In any case, I'm fairly confident I can strip the coating off with my new buffer. I'll need to wait til tomorrow and get some before and after pictures.

 

[Frobe22]

You do realize your light output will get dimmer when polished?
LED brightness is dependent on temperature, and polished aluminum is not capable of getting rid of heat as good as painted/anodized aluminum.
According to a test Newbie did the temperature difference could be nearly 20°C (36°F).

 

[Noctis]

Well it's a good thing I'm not doing this on my 6P then.

I'm also pretty sure heat would only become an issue if I have it on for longer than 5 minutes, and I rarely do.

 

[thebeans]

Well it seemed to work just fine on a cheapy light with anodizing. Might be a bit harder to remove the anodizing off a higher quality light though. Still, I think what's important is that the hardness of the abrasive is higher than the hardness of the anodized aluminum.

I seem to remember hearing something similar about the tailcap, but I can't seem to find that post.

In any case, I'm fairly confident I can strip the coating off with my new buffer. I'll need to wait til tomorrow and get some before and after pictures.

Yes please post before and after pics!! I am interested to see how just a buffing wheel will work on removing anodizing in case I decide to strip another one in the future. But honestly, the chemical stripper worked so well and was so cheap that I will probably use it again if I de-anodize another one.

 

[Noctis]

After 5 minutes on the buffer with both white and brown tripoli, the anodized aluminum only turned slightly blue.

I guess I was right when I made that comment about the anodizing on a cheapy light, because the anodizing on the DeCree seems almost diamond hard.

DeCree 1, Buffer Wheel 0

I guess I'll have to buy some drain cleaner, nail polish, and nail polish remover <_<

 

[RepProdigious]

Blue? At what speed were you polishing, sounds like it got mighty hot.....

 

[Stillphoto]

Buffing is no where near abrasive enough to remove hard anodizing. Check for another thread about "polished hard anodizing."

I've done the draino strip numerous times with different bodies, all to great success.

Just remember, every piece is different, and that can mean one (or every) piece of metal was made from slightly different stock of metal. Thus, even with a perfect strip job, you may end up with pieces that appear slightly different after stripping. When polished, it'll all look good.

 

[gunga]

I've used oven cleaner myself (easy off, pump spray) to remove anodizing. Yes, it is still quite nasty to work with, but works quite well.

 

[thebeans]

After 5 minutes on the buffer with both white and brown tripoli, the anodized aluminum only turned slightly blue.

I guess I was right when I made that comment about the anodizing on a cheapy light, because the anodizing on the DeCree seems almost diamond hard.

DeCree 1, Buffer Wheel 0

I guess I'll have to buy some drain cleaner, nail polish, and nail polish remover <_<

I didn't remove the anodizing on my "Cheapy Light" by buffing it off. I knew that would not work. Even if the buffer could get most of the ano off, you would be left with black in the knurling and other places the buffer could not reach. You could sand the ano off and then buff to bring back the shine but why not just use a chemical stripper like we know works? Then you can use your buffer to get whatever level of shine you want from sort of matt to mirror shiny. If you don't want to bother with the super strong drain cleaner, you might consider Greased Lightening cleaner. I went to Lowe's looking for something to remove anodizing and when I read the label on the Greased Lightening, I knew I had found what I was looking for. It said right on the label to not get it on anodized aluminum. I worked like a charm as you can see in the pics I posted above. It was much quicker than I thought it would be too. If you can get your light apart, the chemical stripper is the way to go.