Series 1 Engine Paint Plan - Details Please

[ChrisZ]

Is it common for the aluminum valve cover to "oxidize" black over time?

Maybe the PO have tried to clean the cover with the wrong acid, some acid will make aluminum look black, you can try to clean it with the right acid, have a look at Caswell plating's homepage.

Chris

[JohnnyO]

Clean Aluminum or clean black????

I buffed an area the size of a nickel and it came out as clean aluminum. That is why I thought maybe it was oxidized or maybe I should have said tarnished.

Clean Aluminum or clean black????

Clean cast aluminum is stock.

Has the valve cover been Black Anodized? Did buffing it result in semi-gloss black??

I dont think it was anodized. I first thought it was painted because the black (dark grey actually) was uniform, not pitted or raised.

Carl, what do you use to clean these up? I dont want the polished look. I got over shiny objects at about 3 years old:)

TIA,

John

[Carl Beck]

Hi John:

I glass bead blast them... with a medium/fine bead. They usually come out of the blast cabinet looking pretty close to new. Mild bead blasting will usually remove most surface stains - - but you don't want to get carried away with the pressure. You also don't want to leave any media inside under the baffels etc.

Finish off with a very light coat of "Dull Amuminum" paint - to retard oxidation and help prevent stains.

FWIW,

Carl B.

[AZ-240z]

Now a question I have. Was the alternator pulley painted or plated? I know the fan blades are plated, but the engine service manual, even though black and white photographs, shows what appears to be a painted pulley.

Chris, that has been a quandry for me, also. I have always thought that the pulley was painted a semigloss black with the fan done in yellow cad or zinc.

I bought a factory remanuf. grapefruit alternator on ebay, factory stickers and all, that had that finish. I also have a second reconditioned grapefruit alternator I purchased locally from an auto electric shop. It, too, had a black painted pulley and am assuming the shop just redid the original finishes.

I, also, have a picture of a white '72 z with 16M original miles on it showing a yellow plated fan and pulley. I am leaning toward the black pulley finish right now.

Dan

[JohnnyO]

Hi John:

I glass bead blast them... with a medium/fine bead. They usually come out of the blast cabinet looking pretty close to new. Mild bead blasting will usually remove most surface stains - - but you don't want to get carried away with the pressure. You also don't want to leave any media inside under the baffels etc.

Finish off with a very light coat of "Dull Amuminum" paint - to retard oxidation and help prevent stains.

FWIW,

Carl B.

Thanks Carl. I am going to get started right now. I just came back with the needed supplies.

I will post pictures here.

Thanks All!

[Zealous]

Post before and after pics when you do it would love to see the progress

[JohnnyO]

Post before and after pics when you do it would love to see the progress

Here are the pictures. I think it turned out nice. I blasted the thermostat cover also to get a feel for the correct pressure. I ended up blasting all the old finish off at about 70 psi with 80 grit glass beads. This did a pretty good job but left some "shadowing" in area so after the worst of it was clean I followed it up with a brief 90 psi blast to even it out.

I painted the thermostat housing with aluminum hi-temp paint. I am unsure whether I like the look or not. Maybe clear?

John

[Zealous]

thanks, looks liek I definitely should get a media blaster

[DeesZ]

Johnny'O - Nice work.

Carl recommended a "dull aluminum" paint. I've experimented with that stuff recently, and can say IMO it gives a better final look than a clear coat. Clear coat is nice, but it darkens the media blasted surface (kind of looks 'wet', a shade or two darker).

For looks, my first preference on these aluminum parts is just media blasted with no finish coat. But, the parts are prone to staining/discoloring when they encounter various fluids, and as Carl mentioned, oxidation. Second is hi-temp dull aluminum. Honestly, it makes them look great, and gives them a protective coating. Third, and still acceptable IMO, is a hi-temp clear coat.

From what I see in your picture, you likely used a glossy aluminum. For my taste, and I think yours based on your comment, it's just too shiny. Give the dull stuff a try and I think you'll be quite pleased. I am using a product off the shelf at NAPA - "VHT" (Very High Temperature) Header Paint - Flat Aluminum/Aluminum Matte - Product # SP-117. Give it a try. I'm confident you will be pleased.

Attached are several pictures of two parts; both glass beaded, one clear coated, the other (on the right) painted with the VHT.

There are lots of other 'before & after' pictures in my gallery as well. I'm having a real blast with my blaster.... addicting, aren't they??

[JohnnyO]

John,

I agree. The clear gives it a wet look at least 1 shade darker but I did prefer that look over the standard Plasti-Kote Aluminum paint I found locally.

I use VHT clear satin from napa, I will run by there today and pick up VHT Flat Aluminum and see how it looks.

Thanks,

John

[Zak's Z]

I refinished most of the parts for the motor last summer, and I had the flat aluminum and the shiny aluminum paint. I didnt like the look of the shiny aluminum, and the dull was just a tad too dull. So I painted everything with the shiny one, then misted on the dull one to tone it down. Engine is all wrapped up in the garage but I'll see if I have any pics...

[DeesZ]

I refinished most of the parts for the motor last summer' date=' and I had the flat aluminum and the shiny aluminum paint. I didnt like the look of the shiny aluminum, and the dull was just a tad too dull. So I painted everything with the shiny one, then misted on the dull one to tone it down. Engine is all wrapped up in the garage but I'll see if I have any pics...[/quote']

Interesting approach, Zak's Z. I'd be interested in pictures! Thanks!