302 Valve Cover refinish

[Prackman]

I have a 69 302 with repop aluminum valve covers that are too shiny.  What it the best process to get these to the dull finish look of the original aluminum valve covers?

[ko-lek-tor]

http://www.airforums.com/forums/f4/how-to-oxidize-aluminum-92726.html

[z28z11]

I have a 69 302 with repop aluminum valve covers that are too shiny.  What it the best process to get these to the dull finish look of the original aluminum valve covers?

Send them to Jerry MacNeish. His restoration process is spot on from the ones I've seen. I'll likely forward mine to him if I live long enough.

Regards,
Steve

[Stingr69]

Jerry did a set for me and they came out great. Takes a bit of time but they look perfect now. 

[Hans L]

Jerry did the valve covers for my Z as well (rebuilt and restored the engine/trans as well).

Here's a few pics to show how they turned out:

[firstgenaddict]

Yes the shiny shiny need the sheen knocked off...
Wheel acid works extremely well for this, may be able to just use easy off oven cleaner, either remover or tape the emblem up well.

[L78 steve]

What is wheel acid? I have a dull 660 therm neck that needs brightening.

[X33RS]

Oven cleaner does it.  I have a wheel cleaner in a spray bottle that is acidic and dulls them up nicely.  I actually found it by accident when I sprayed it on a wheel and it peeled the clear coat off 

On really nasty looking covers I'll lightly glass bead them, then scrub with SOS pads and warm water for a nice smooth uniform appearance, then spray on an acidic cleaner.  When finished they look just like the covers pictured above.

I had to buy a new set for my engine and the darn things come polished.  I may just run as is and wait to go through the process until I restore the car, because it's hard to keep them looking nice once you get the correct appearance. 

[69Z28-RS]

What is wheel acid? I have a dull 660 therm neck that needs brightening.

I'm glad Steve asked this .. so I wouldn't have to..    Now we all await James' response and definition for 'wheel acid'... (I don't recall this type from Chemistry class!)..

[68camaroz28]

Jerry did the valve covers for my Z as well (rebuilt and restored the engine/trans as well).

Here's a few pics to show how they turned out:

Hans, great looking but wonder why the bell housing bolts not painted? Simple fix!
On valve covers does it not seem many of these restored valve covers look too much like a alum intake and that is not what I remember or have seen on survivors. I have a pair of nos with dated box Jan1970 and they have a type of smooth kind of satin look, not shiny, but not that alum intake look either. Skips 09D late Z have same look, that being of a smooth not dull not shiny look.

[firstgenaddict]

They were pressure cast or die cast aluminum when the molten metal is cast in a die vs sand cast it looks different, think of a trans tail shaft housing or side cover vs the main case
I over spray the valve cover edges along with the intake edges, they were on the engine when it was painted.

[X33RS]

On valve covers does it not seem many of these restored valve covers look too much like a alum intake and that is not what I remember or have seen on survivors. I have a pair of nos with dated box Jan1970 and they have a type of smooth kind of satin look, not shiny, but not that alum intake look either. Skips 09D late Z have same look, that being of a smooth not dull not shiny look.

Easy to get that look.  After I lightly glass bead them, I use fine 0000 SOS pads that have the soap imbedded, some warm water, and then lightly scrub (fore and aft) same direction.  It eventually takes the dull finish from the glass bead, smooths the surface and starts to create a mild sheen.  The further you go the more sheen you get.  Stop when you're satisfied.  Sometimes I'll dust them with satin clear so they are easier to wipe off and keep clean (they don't stain as easily.)  But I mean "dust them" because too much darkens the aluminum, and you start over.

[firstgenaddict]

Here is a VERY early take off diecast Corvette script valve cover which shows the correct as diecast finish, the brightness goes away quickly in use.

[69Z28-RS]

James:  you wrote:  "Yes the shiny shiny need the sheen knocked off...
Wheel acid works extremely well for this, may be able to just use easy off oven cleaner, either remover or tape the emblem up well."
----------------------------

Some of us are ignorant as to what 'wheel acid' is..  Would you please enlighten us?

[firstgenaddict]

People used to call the wheel cleaner which removed heavy brake dust - wheel acid and the reason I say that is because it said on it do not use on Aluminum wheels, will discolor and damage finish. 
I can't remember the product which was "wheel acid"-
I typically use easy off oven cleaner. as stated.

I had a pair of Z28 valve covers which I though were beyond all help. 
I used black beauty first.
Then sanded the roughest pits out with 80- 120 - 220 - 320,
Then I glass beaded them to get a uniform surface,
Then oven cleaner which really gives a nice oxidation to work back from.
Then scotch brite with aluminum cleaner, not aluminum polish.
 
This is that pair of valve covers right after they were done...