Ordered the judging manual from NCRS. Figured I would save a lot of time asking questions and can get back to work on the car.

Although, one more question. Was cleaning up one of the front dust shields (definitely not hot dip galvanized) and there is no part number. It looks just like the one Tim posted in post #3. Am I right in assuming that, just like the exhaust tips, the assembly line parts have no part number stamped on, but the over the counter replacement ones DO have a stamped part number?

BTW, I looked at the rears. Will be a while before i disassemble and get to them, but there does not look to be any bare metal on the edge.

Top Two pics are 2nd Gen Camaro NOS 2nd design with Rolled Edge (not Sharp)
Bottom Two pics are 70 Camaro Survivor ..........

I have always thought these were stamped form Galvanized Sheet....but wont argue
with Dave about non rusting edge............

Chuck. Gotta keep in mind that NOS isn't always the same as assembly line. Things changed over the years.

In the early 70s I purchased a brand new hi-rise for a 69 Z/28 from the local Chevy dealer. Instead of a 472 intake, I got a 2116 intake. They look identical.

Would vapor blasting clean my originals but leave the plating intact?

If not, how about dry ice blasting?

Depends on the media in the Vapor hone. I use a fairly fine glass. ( won't remove rust ect)

Take a Look at Level 1 dry ice blasting. That won't remove any material. And will leave plating intact. ( one of the best benefits imo )

Lynn,

Got any pics of your backing plates? I cleaned the plates from my 67 L79 with nothing more than the parts washer and Boshield. I still maintain they are cad plated.

Tim

13 degrees f here today. My shop is heated, but giant wuss that I am, I don't know that I want to go outside long enough to go down and turn on the heater.

I cleaned one in the solvent tank. Still has some residue on it. Tim, my guess is you are a much more patient man than I am.

Will try to get pics sometime soon.

Walnut sheals ? (never tried for that application) JohnZ mentioned many years ago RIP, which I've used quite a lot is glass beading at a low 25PSI which works well when trying to keep the same texture/look.

I use my CERAMIC Media Shaker/Tumbler Machine to CLEAN the Galvanized Surface.....as well as my Aluminum Die cast parts, Tie Rod Ends and many other parts

Here are pics of the RF dust shield.
Sadly, the LF is not usable. But, I have a spare. Just haven't tried cleaning it up yet.
I may be searching for a survivor LF.
Glad to have two pristine rears.

Frankly, I cannot tell just by looking whether these are cad plated or galvanized. I am certain they are not hot dipped galvanized. That process leaves a very distinct pattern. Just LOOKING at them without any kind of chemical analysis, they COULD be electroplated galvanized. Hard to tell on a 54 year old part!!!

Roy S told me:
"Front: dull cadmium without dichromate conversion coating. These tend to get chalky look to them with aging.
Rear: punched from galvanized metal sheet, sheared edges are bare steel from the shearing action which could and did rust."

I let this one soak in solvent (Crown PSC1000) for about a week; then scrubbed on it with a soft scotch pad. As you can see, there is still some discoloration on it. I didn't want to scrub hard enough, even with a fairly mile abrasive, to disturb the original finish.