Alternator oxidation - removal

**jopper** · 01-22-2010, 01:36 PM

Hi,

I have been searching for a solid solution to the problem of oxidation on aluminum parts in my Corvette engine bay. The alternator has some oxidation on it and I have tried to wipe it off but it looks like it will take a little more serious effort. I would like to get this white powdery looking oxidation off of it and other aluminum parts in the engine bay area. In your area on engine detailing and in other forums there is discussion about covering and protecting the alternator and I want to make sure I don't damage it while using polish, water, or any number of the recommended fluids to accomplish the job... and there have been several. If it were not the alternator, I would be less wary.

What is your advice on removing this oxidation, process and product wise. Once removed, what is the best protectant to use to help maintain a clean finish? I have heard of everything from WD40 to a range of polishes.

**mbkite** · 01-22-2010, 01:39 PM

Replacement

Mike Phillips · 01-22-2010, 03:04 PM

Just to double check, your alternator has a rough texture finish?

We're not talking about a polished aluminum alternator are we?

I don't know that I've ever seen a polished aluminum alternator. I've owned a chrome Chevy Alternator on a big block chevy engine in a 1959 Cadillac and my current 454 has a brand new NAPA Alternator with a rough finish.

If you want to keep aluminum from oxidizing and it has a rough surface texture, you're going to need to find a way to create a barrier film over the aluminum to seal out moister and air.

I've sprayed mine with WD-40 like you've mentioned and it doesn't seem to have ever hurt anything. I'm taking an alternator to an electrical motor repair and rebuilding shop here locally, I'll ask them if there's any issues with spraying or wiping the exterior case of an alternator with WD-40 or if they have any other suggestion.

Here's the one on my current motor, I don't really see any oxidation problems on it yet but it's only a few months old.

**Harleyguy** · 01-22-2010, 09:47 PM

Originally Posted by jopper

Hi,

I have been searching for a solid solution to the problem of oxidation on aluminum parts in my Corvette engine bay. The alternator has some oxidation on it and I have tried to wipe it off but it looks like it will take a little more serious effort. I would like to get this white powdery looking oxidation off of it and other aluminum parts in the engine bay area. In your area on engine detailing and in other forums there is discussion about covering and protecting the alternator and I want to make sure I don't damage it while using polish, water, or any number of the recommended fluids to accomplish the job... and there have been several. If it were not the alternator, I would be less wary.

What is your advice on removing this oxidation, process and product wise. Once removed, what is the best protectant to use to help maintain a clean finish? I have heard of everything from WD40 to a range of polishes.

Without changing it out for a chrome one don't knock yourself out to much.Join the club of corvette owners that have the same problem.I use a small brass wire brush to clean mine.I've never lost a show because my aluminum parts weren't polished out.This is a very common problem.

**jopper** · 01-22-2010, 11:04 PM

Hey thanks guys. I dont need it to be polished like a mirror but it is just bugging me.

I got a brass brush and I am going to go over it tomorrow with a few options very carefully and see how it goes. I tried some Mothers aluminum polish and it was not a real success. WD40 was not either. I think if I can get it reasonably clean like yours in the picture, I can use Aerospace 303 or another protectant to keep it up.

Seems as was noted in the last post, this is a common problem for Corvette folks and with all the products out there - should be one that can work without going to a chrome alternator

I'm just sayin......

Mike Phillips · 01-25-2010, 10:45 AM

This last Saturday I dropped my alternator off at the Electrical Motor Repair and Rebuild shop and just this morning the owner called me to tell let me know my alternator is ready to go. While I had him on the phone, (he wasn't there on Saturday), as asked him about preventing oxidation on the textured aluminum case on most alternators and he said he had know recommendations to prevent the problem but also said to not spray the outside of an alternator with WD-40 or similar types of products.

Sorry I didn't receive any miracle suggestions but I did want to follow-up since this topic came up at the time I was dealing with an alternator issue.

**Jossy92** · 01-25-2010, 10:50 AM

Whew. Was considering doing that before my first engine detail. Gotta figure out if it is an electrical issue or an aluminum issue.
Saved by AG again.

**jopper** · 01-27-2010, 11:26 AM

I am going to try a brass brush to get off the major problem spots and follow up with something called aluminum slick that was recommended to me on the Corvette Forum - it says it will remove and polish aluminum. I wont spray it on but wipe it carefully on the case areas and see what happens...... I still say there ought to be a solution for this very common issue. Corvette Fever magazine had a recent article about removing the alternator and using steel wool to bring it back. Obvious issues with small particles entering the alternator if not careful...

Mike Phillips · 01-27-2010, 11:33 AM

Originally Posted by jopper

I am going to try a brass brush to get off the major problem spots and follow up with something called aluminum slick that was recommended to me on the Corvette Forum - it says it will remove and polish aluminum. I wont spray it on but wipe it carefully on the case areas and see what happens...... I still say there ought to be a solution for this very common issue. Corvette Fever magazine had a recent article about removing the alternator and using steel wool to bring it back. Obvious issues with small particles entering the alternator if not careful...

The problem with the alternator case is that it's textured, probably made using a sand cast mold.

One option would be to have your alternator or a duplicate disassembled and then send the case out to a shop that caters to polishing aluminum and they'll have the tools to quickly grind the exterior smooth and polish it till it looks like chrome.

Then have it reassembled and install it. From there on if you polish it periodically by hand with a quality aluminum polish you'll be able to keep it looking like chrome. The key will be to polish it often so polishing it will be quick and easy. Once you let it go for a while the aluminum will oxidize and stain and then it won't be quick and easy to restore the chrome look. With a smooth case though, polishing and maintaining is doable, with a sand textured case, rubbing with a light oil to the exterior or possibly with the product mentioned above is about your only option.

"Find something you like and use it often"

That's the key to maintaining polished aluminum on ANYTHING...

My Sanger Drag Boat had a lot of polished aluminum so I've had years of experience maintaining not only all the aluminum inside the boat but also the 4 Slotted Mag Wheels on the tandem trailer. Getting everything polished up to a chrome appearance was hard, your fingers would get sore after a short time of hard rubbing. Maintaining was easy.

**CharlesW** · 01-27-2010, 12:22 PM

I'm with Jopper.
It seems like there should be some way to restore textured aluminum to its original appearance.
Not polished, but clean and uniform in appearance.
This isn't just with alternators. Our vehicles have textured aluminum in several places.
Motor mounts, intake manifolds, engine covers are some I can think of right now.
The brass brush sounds like it might be worth trying.
Maybe even a stiff bristle nylon brush with some APC would help.
A chemical cleaner would get into the texture better, but the possible problems with a chemical that strong would make me hesitant to try it.