Aluminum Valve Cover Cleaning

[Car54280ZX]

I want to restore the valve cover on my L28 engine to original stock condition. 

Somewhat difficult due to presence of cosmoline. In some places the aluminum beneath the cosmoline is shiny as it was when I purchased the Z-car new in January 1981 (Manufacure date 09-1980).

I purchased Sharkhide aluminum cleaner, very expensive for a quart!! Tried it, a 3 parts water to one part Sharkhide ( rather strong) and it foamed-up per instructions on the valve cover side facing the fire wall but it didn’t do much.

Does anyone have experience using this on valve covers or other engine aluminum parts that need to be cleaned (bell housing, alternator, stock intake manifold, etc.)?

I saw other posts about wet glass bead blasting but I don’t have a local source. I “do” have a local source for dry glass bead blasting. 

How do you get the cosmoline off? Will the Sharkhide cleaner work after cosmoline is off? The Sharkhide cleaner is used for shining up aluminum pontoons on boats. Should work on Zcar aluminum engine parts.

Any comments would be appreciated!

[240260280]

Eagle One Etching Wheel Cleaner may help: http://atlanticz.ca/zclub/techtips/wheelclean/index.html

The only other ways I know are:

1. Vapour Blasting

2. Painting/Powder Coating

3. Sanding, polishing, and buffing

 

[siteunseen]

I sand blasted this one then sprayed it with clear satin high heat metal protector from Eastwood.  Turned out good, to me.

 

[SoCalJim]

Was the lettering masked before sandblasting, or subsequently sanded smooth?  That sure does look great!

[Car54280ZX]

Many thanks! I mounted my valve cover on plywood too. Used an old sewer plug for the oil cap opening. Plugged the rest of the holes with 6 mm dummy fasteners. Not sure how to plug the breather pipe. I’d rather not take it off as it looks like it’s really on there and a new fitting is pricey..

Also, take note of the greenish blue mark beneath the cosmoline. Must have been made by the factory in 1980. Is there any significance to keeping this as I want to keep as much originality as possible. Would I loose points at a car show if it has been removed during cleaning?

[Car54280ZX]

14 minutes ago, SoCalJim said:

Was the lettering masked before sandblasting, or subsequently sanded smooth?  That sure does look great!

Hmm. This is the valve cover “before” doing any cleaning. It’s under the cosmoline. Looks nice in some places but some mouse urine corrosion on the side of the valve cover near the intake manifold. Mice built a huge nest on the manifold. Car sat for 15 years in a farmhouse garage. 25,600 original miles. Had to rebuild engine which I hope to get back today so I can start putting everything back together.

I always kept it garaged but mice got into the engine compartment. Massive nests on the intake manifold and in the ventilation squirrel cage blower (another problem). And of course the mice loved the exhaust pipe too.

Maybe I should mask off this mark. Also there is another mark on the other end of the valve cover that I should mask before cleaning?

Another option is “do nothing” but not sure how it would fare in a show. 

Comments are appreciated! 

[Car54280ZX]

2 hours ago, siteunseen said:

I sand blasted this one then sprayed it with clear satin high heat metal protector from Eastwood.  Turned out good, to me.

 

I will check out this product. I purchased the Sharkhide from Eastwood.

[Patcon]

When you say cosmoline, do you mean like heavy gun grease or more like a dried urethane? I would try lacquer thinner to get it clean. Then bead blast it with fine beads. Then use sharkhide or one of the diamond clears for protection

[Car54280ZX]

7 hours ago, Patcon said:

When you say cosmoline, do you mean like heavy gun grease or more like a dried urethane? I would try lacquer thinner to get it clean. Then bead blast it with fine beads. Then use sharkhide or one of the diamond clears for protection

This stuff which I understand is cosmoline, is not a heavy gun grease. It’s dry. I understand that it was applied at the factory before it went on the boat from Japan to USA, to minimize salt spray on the valve cover and manifold.

I would describe it as a clear urethane. Tomorrow I’m going to try Acetone, and see what happens. 

The Sharkhide doesn’t do squat on the cosmoline/ urethane. It did well on cleaning my manifold. But it’s slow. Like watching corn fields grow. See the two photos, before and after. But not finished yet.

 

[Car54280ZX]

Great news to report on valve cover cleaning. I’m using a variety of chemicals and I’m constantly watching it, never walk away when doing this.

I’m using “Zip-Strip” Premium Paint and Finish Remover, Mineral Spirits in a chemical spray bottle and a very fine powdery cleanser called “Bar Keepers Friend” with water.

Results are amazing. Takes the lacquer / cosmoline off and beneath is a very nice aluminum surface. 

I still need to get the cosmoline off the edges of the letters on top of the valve cover and do more light scrubbing with Bar Keepers Friend before I spray it with Sharkhide aluminum cleaner and then with Sharkhide aluminum protectant.

Here are a few photos. More to come.