White Spots/Corrosion on Aluminum

[Eddie 70]

I am wondering what can be done about white spots/corrosion on aluminum engine parts. I have the Chevrolet Bowtie Aluminum valve covers on my engine that has been setting on the stand in the garage. When I pulled the cover off the motor the covers had dulled and were spotted in a few places. I was heartbroken. I haven`t even got to drive the car yet.

What can I do to remove the white spots on the valve covers?Thanks for any help.

 

[Twin_Turbo]

Polsish (or glass bead blast) them and use some clear lacquer on them. You could also paint them w/ aluminum colored paint (Rust-o-leum Hard Hat sells a nice aluminium colored paint, they even have magnesium, stainless and some others)

Marck

 

[GerryLP]

Eddie,

If your valve covers are suffering from exfoliation (flaking of the metal) or intergranular (leaves pitting on the surface) corrosion, then the covers are probably gone (or unsalvageable). However, these are not used in a high stress area (as differential housings or aluminum heads).

If you only have powdery residue and no pitting, then use Mother's Wheel and Aluminum Polish compound. I works great for these situations. Use a canvas polishing wheel. Sears has 4" and 6" wheels for this. If you can, get one to remove the aluminum corrosion and another for bringing-on the luster.

The lacquer is a good idea also. But buy the one that is for aluminum. Some lackers will change the hue? :confused (or tone) of the aluminum's natural color.

Finally, you can also powder-coat them in your favorite color (after treating the corrosion). My 81's valve covers are black with the cooling fins exposed in the natural aluminum color.

 

[Twin_Turbo]

I doubt he has intergranular corrosion since they're not really old valve covers. You have to leave them to rot for quite some time to get that.

Eddie, do you have these?

I have those too. I'm going to powdercoat mine black, then remove the coating from the bevelled letters & bowtie. Then the bowtie will become red and the chevrolet letters will be polsihed aluminum. Just like this:

Marck

 

[smurfvet]

If the covers have no coating on them try these two options for a simple on the car fix-

1) Simichrome paste works great on chrome or aluminum to clean up the surface and remove oxides. It comes in a small tube that seems expensive, but like Bryllcream, a little dab'l'do ya! Put a small amount on a soft rag and the white oxide will leave. You can get a low level "buff" on the surface as well. This stuff protects the aluminum, but remember that the white stuff you removed is aluminum oxide- it was part of the cover at one time. You might leave small voids or gaps where the stuff was. 3M professional products makes the same stuff in a small (6 or 8 oz) can. Again, not too cheap, but it works. I got mine at a refinishing wholesaler, I don't know if Autozone, etc. would carry the professional stuff.

2) Mothers makes a mag/aluminum wheelcleaner paste that works ok. It's white and comes in a can.

If the covers have been sealed, do what Twinnie and GerryLP said. That's the only alternative, to bead the covers and repaint.

 

[Eddie 70]

This is what I have.

 

[JohnZ]

Once you get the spots off, here's another alternative you might consider - I used a sanding block on the bowtie and letters until they were flat, shiny and smooth, then shot the covers with hi-temp clear - has held up very nicely.

 

[Twin_Turbo]

Eddie,

What kind of water pump do you have there? An aluminium Weiand Team G ?

Marck

 

[Eddie 70]

This should be the picture of what I have. It has changed some. This was taken in the spring of this year. I will see if I can get another one tonight if you guys would like.

BTW Mothers is doing quite a nice job of it.

 

[Dave L.]

Eddie- Beautiful engine!! What brand of headers do you have there?

Dave

 

[Eddie 70]

Twinnie, yes that is a Weind Team G.

Burglar, thanks for the compliments. The headers are Street and Performance brand. They have a four bolt flange. I hope that will keep gaskets alive longer.