Polishing Aluminum
 

I got this idea that I wanted to polish some Blue Thunder Competition valve covers. I think my goal was to have a project and make some relatively unique valve covers. I bought a polishing kit from Caswell which came with 8" wheels and the different compounds you would need. It was around $100. Thankfully I have a 1-1/2 hp motor with an extended shaft that is perfect for this.

Never having polished anything before I thought I would dip my toe in the water. I bought a Shelby "billet" alternator bracket set. A side note on the Shelby billet bracket, it appeared to be cut on a water jet and moved as it was being cut so the edges were jagged in some places. It was bead blasted over this uneven area. This was actually a good thing in this case because it caused me to have to sand those areas smooth before I started polishing. That gave me experience with what grit to sand to. The answer to the question what grit should I sand to is, as high as you can. Sanding is easier than polishing.

So I polished up my brackets. Didn't finish I need to pick up some finer paper for my DA. 180 is not enough in my opinion. They are coming out good and will be good when I am done BUT I am not feeling the valve covers for two reasons. 1.) It is a dirty finicky job. 2.) And more importantly, Aluminum is soft and I think they would get easily scratched and become a difficult maintenance item. Polishing a new valve cover is not a big thing, a used one would be more difficult cleaning the inside to start and them cleaning it again before you put it back on the car.

So I thought I would share my experience. I would not discourage you from doing it I would just pick my places very carefully. I'll post some photos before I am done.

JMHO: but the best way to polish anything is take it to a plating shop and let them do it. They have the tools and cheap labor.

Good on you Bill for wanting a have a go at this, nothing more rewarding than doing it yourself.

Can't wait for your pics.

Having said that, I hated the maintenance of polished alloy after one manifold I had done a few years ago.
Cost me $60, looked like a mirror on day one, but I just couldn't keep it like that.
If I did it again, I'd go for a chrome plated finish.

I've fabricated and polished several aluminum parts for various projects - but not for the Cobra. As Gary says, it's a bit of work to keep looking good. For the car, I prefer chrome or stainless.

Polished aluminum looks great. If you get tired of polishing it, some members have suggestions in this post: http://www.clubcobra.com/forums/supe...m-shiny-2.html

A used or fine wire wheel on a grinder polishes things pretty quick. Also cleans gasket material off pretty nicely. Just be careful.

polish
 

Busch Aluminum Polish The Best Hands Down.Sand With 400 Then Hit With The Buschs. Warning Knowing When To Stop,Gets Brighter Every Time.

Finished
 

I think I am going to give it a brush finish by the adjustment screw. It is going to get all marked up during install.

http://bill-stan.smugmug.com/photos/...-ghtWpQM-M.jpg

http://bill-stan.smugmug.com/photos/...-ZmKFcb8-M.jpg

I can't imagine having a lot of polished aluminum, you would have to be so careful.

Bill,

I will usually sand clear to 600-1000 wet or dry before polishing if possible, makes the polishing go easier and faster. Proper compounds and proper buffing wheels also make a difference.I have used the clear spray coatings on some things to retain the shine without much maintenance. Just don't use it like paint, real light even coat, I've never tried it in a fuel or chemical environment such as a intake. I would never use a wire brush to polish anything. Wait till you have the wheel grab the piece your buffing and throw it......Go easy and let the wheel do the work.

Paul...

hard work
 

a buddy of mine polished my Ford alternator for me several years ago. I bet it took him a week to do it.
years later it crapped out. I bought an alternator and took both to a alternator repair shop and had them to exchange the case.

Cleaned it up and put it back in my Cobra. Bobby had to many hours into polishing it to just throw it away.

I polish a lot of aluminum parts but it's hard to get a Chrome like finish because the aluminum is so soft and easy to scratch.

I do clear coat most of my aluminum.
I replaced an aluminum water pump because it looked dirty on my Cobra motor. I clear coated the new pump and it looks good years later.
On some aluminum I just bead blast it and clear coat because polishing it so time consuming.

Dwight

What do you clear coat it with?

I polished just about everything on my engine and motorcycle. I use this to seal the polished aluminum. It lasts about 2 years depending on where you drive etc.

http://www.summitracing.com/search/brand/shineseal

You can clean up the aluminum just by washing it and it still looks great.

Ran into Michelle of All In One Polish last night after the Bradenton regatta. The polish is water based and looks like a very fine aluminum oxide suspension plus a reducing agent and a mild wax-like additive. She does an impressive demo. Had some some pretty rough looking aluminum in several different forms and with < 20 seconds and a rag she was able to put quite a shine on it.

All In One Polish

the most important step in polishing is never use your hand to sand. Your hand makes straight scratches, always uses orbital. the orbital makes scratches also but you eye can't follow. I struggled polishing my spf wheels which were severely oxidized. the key was orbital sander 2" from garbage freight. than the real key was i ordered a kit that guys use to polish aluminum fuel tanks for big rigs. BINGO. the cotton buffs you got are a little soft to get the scratches out. what originally took me 4 hours with bad results took 30 minutes with mirror finish.

Bill I've used Eastwoods clear sealer in a rattle can and some that I bought at WalMart. Both do good.

Dwight

never used this but it looks good

Dwight

ShineSeal Aluminum Sealer | Hotrod Hotline

I have some shine seal i will sell you for $40 if u interested. I paid $100 sold car before I could use it. $40 plus shipping