leperboy

I put polished flat dishes on my 928 today. I am using the center caps from the old anodized wheels with them. So, tonight I de-anodized and polished them. This is a pictorial primer on how to de-anodize aluminum and polish it. This same method can be used on wheels or any other pieces. I've used this method for years on aluminum trim for old cars.

What you'll Need:
- 100% Lye (I bought mine at Ace. It's in the drain cleaner section)
- Wet/dry sandpaper suitable for metal in grits 220-400-600-800-1600 (any good body shop or hardware store will have them)
- A bucket
- A cup of water (a cheap cup you can toss is best)
- Rags, preferable terrycloth or something with a textured surface



1. Fill the bucket (or large tub) with a 5% solution of lye. The 5% is by weight. So, for every gallon of water use about 6 oz. of lye. Use hot water and wait a few minutes for the lye to dissolve. You can use a more concentrated amount, but it will strip the aluminum more aggressively. DO NOT TOUCH THE LYE OR LYE SOLUTION WITHOUT GLOVES.

Here are the four caps I polished, before polishing. You can see a lot of scratching in one piece. Another had pitting in one corner:


2. Drop the pieces you want to de-anodize into the solution. Let it sit for about five minutes. The next two pictures show the chemical reaction of the aluminum and the lye solution.




3. Don't let the pieces sit too long because the lye solution acts on the anodized aluminum AND the bare aluminum. Letting them sit too long may pit the raw metal. Pull the pieces out after five minutes and look at them. If they aren't completely chalky to the touch, put them back in for another five minutes.

Here are the caps after sitting in the lye:


4. Now is a good time to look for scratches or other pitting. If it is deep (e.g. catches your fingernail) there isn't much you can do about it. If the scratches are shallow, use sandpaper to smoothe them out. Keep small strips of the sandpaper in a cup of water and keep rewetting them while sanding. If you go dry, it can cause bad scratching. I usually start with the 800 grit and see if it will do the job. If it won't I will move up to 400. Whatever I end up using, I sand out the scratch and then move down to the next finer grade, always keeping the paper wet. End with 1200 or 1600 grit for the final sanding. This is just right for the pre-polish level. Don't jump too quickly down in grades or you will end up with scratches the finer sandpapers can't remove.

5. If there are no scratches or pits, or you have sanded them out, use a good polish (I like Mother's) and a terrycloth rag to polish. Polishing is going to make the rag and your fingers black as it buffs out the micro-fine pieces of aluminum. It may take three or four passes with the polish, wiping off the excess after every pass. You will end up with a mirror shine. The more you polish the smoother the surface. But don't use the same polish for too long before wiping clear and starting over because the abrasive in the polish breaks down and becomes ineffective.

You can also use a polishing wheel with a very soft buffer wheel and the same metal polish. I chose not to polish the shields of these center caps, but if you want to, about the only reasonable way of doing it is with a polishing wheel, a wheel attached to a drill, or a small buffer on a Dremel. You will need many of those for most jobs since they will blacken very quickly.

Here is a half-polished center cap:


6. Make a final wipe of your piece with a clean rag. Then spray them with degreaser and wipe with a microfiber towel. Follow with a bare metal sealant. Rejex works well, as does Boeshield T-9. This will keep the pieces from oxidizing or picking up dust. I think the Rejex works better at keeping off dust. The Boeshield lasts longer.

Here is a before and after picture of the center caps:


Here are all four of my caps after polishing. Because of the flash, they look like they have scratches. They do, but they are so fine you can't see them in the sunlight or normal light, and the caps have a mirror finish.



It took me about two hours from start to finish to do the four center caps. For larger objects like wheels, I'd recommend going to CaswellPlating.com and looking at the buffer wheels they sell for drills. The process for de-anodizing is the same, though.

Matt

Mike Frye

Matt,

Those look GREAT! Really cool write-up too. Thanks for taking the time.

I have a set of old caps and I was debating what to do with them. I was thinking strip, clean, polish, then clearcoat? I guess the Rejex bare metal sealant is designed for that, though. Cool.

Jfrahm

Looks great Matt.

Have you tried using dish soap in your wetsanding water? I have started using some, it seems to make the water stick to the paper a bit better.

OT: have you been to that Bohemian restaurant near you on Wads? It's pretty good. Let me know if you want to grab lunch there sometime. Golden Europe, it's called.

-Joel.

leperboy

Mike, I am just using the Rejex that we use for waxing our cars. A regular clear coat likely won't stick to the bare metal, so if you want to do that, I recommend POR-15's Glisten PC or Eastwood's Diamond Clear. Just make sure you have totally degreased the piece because both will bring any residual to the surface and cloud the finish.

Joel, I haven't tried dish soap. Thanks for the tip. I also haven't tried Golden Europe. My wife and I went there one night, but we found there wasn't a single non-meat dish on the menu, and she's a vegetarian. I, however, am not, so would love to grab a bite. Just south of it is a very good and ridiculously cheap Vietnamese restaurant called Saigon Cafe. The name is so generic it kept us away for a while, but I had a fantastic meal there last time.

Matt

Abby Normal

You forgot flour.

Dip your clean rag in flour and the black film wipes off in one swipe.

Jim bailey - 928 International

Also please wear eye protection when using a Lye solution if you happen to drop a cap it can easily splash ...

killav

I have used a product called SIMICHROME in the past that has yeilded outstanding results for polishing aluminum.

Jim bailey - 928 International

Removing the anodized layer is really difficult unless you chemically strip it. It is a very hard surface and not easy to sand or polish.

Bill Ball

Agree, better than Mothers. And I've found Autosol to be even better than Simichrome. Small buffing wheel on electric drill - aluminum cases on the Commando are chrome-like in no-time!

killav

Cool, never heard of Autosol.

IcemanG17

One tool I used on my 1/2 assed polished stock wheels was the mothers "powerball" with the aluminum polish.....it goes in the end of a cordless drill.....it makes polishing the wheels SO much faster.....a must have for polished flat dish owners!!

Bill Ball

I bought the Mother's Powerball and polish. It's not as effective as Autosol. The Powerball itself is very safe due to the long shaft - no chance of your drill hitting metal.
http://www.eastwoodco.com/shopping/p...m_Tube_Autosol

Mrmerlin

Nice Bike Bill,
Thanks for the writeup Matt

Abby Normal

I use a powerball also but don't forget the flour on a clean rag to remove the black film. It's not just for baking and is the best kept detailing secret you may ever get.

Bill Ball

Yes, thanks for the write-up Matt. I didn't know lye would remove the anodized coating.