Alternator oxidation - removal

J

jopper

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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.
 
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.

JimmysNewTop031.jpg


:)
 
jopper said:
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.
Click to expand...
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.
 
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......
 
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.


:)
 
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.
 
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...
 
jopper said:
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...
Click to expand...


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.


:)
 
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.
 
FWIW - I have cleaned the aluminum intake on my truck with Bleach White and nylon brushes before.

Also, FWIW, I have pressure washed over aluminum cased alternators before to get grime off of them after brushing them with APC/Degreaser. Not saying I do it as common practice, or that is a good idea - but I have done it, and had no problems when I did.

If you get water in it will dry out.

DLB
 
CharlesW said:
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.
Click to expand...

If memory serves me correctly, acid or even alkaline cleaners will tend to make the aluminum dark.

I've had good luck spraying Brake Cleaner on dirty textured aluminum and getting it clean without hurting or changing the appearance.


:)
 
From my own experience I have the same aluminum oxidation problem on cars that are not regularly driven. Seems moisture in the air causes the problem. Regular driving heats up the aluminum and evaporates the moisture and keeps the white stuff at bay. If you are a purist then polishing the case is not the answer. You want the original rough texture finish without the white. My best results come from spraying WD-40 on a rag, (not directly on the part) and rubbing the oxidation off. Sometimes parts need to be removed in order to get in all of the nooks and crannies or wrapping a rag around a paint stick sometimes works too. The WD-40 displaces the moisture and provides a barrier for a while but eventually if you don't drive it the white comes back. I would not consider putting a matte clear coating on the part (paint) as if there is any moisture on the part prior to painting the oxidation will grow under the clear coat and only by stripping the paint will you be able to correct that. Leave it natural and use WD-40 on a rag every time you clean the car.
 
An update. Well not much luck with the brass brush. It removes some of the light powder but the deeper tarnish is not touched by it. I think it will take some dedicated polishing effort to get it clean. Not easy to get to all the areas installed but I will work at it. Going to work with Mothers Aluminum polish and see if i can make headway in several sessions.
 
Thanks Mike. I will try the brake cleaner option on a small area and see how it does.
 
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