Plating Question

[KevinCav]

I recently had some parts zinc plated and when I got them back they were VERY shiny--they almost looked like they had been chromed. I had expected a much duller, grayish appearing finish. When I questioned the plater he stated that when new my parts would have appeared the same way, but had become dull and gray from almost 40 years in the engine compartment. Should I believe him? If he is correct, how can I get the shiny new appearance toned down so that it looks more original? Thanks!

[Rainer]

Are you sure your parts were originally zinc plated and not cad plated? Cad is much duller, and is what was originally used on coil brackets, alternator fans, etc. When zinc was used, it tended to be a dull zinc, not a bright shiny zinc like you see in hardware store bolts. I'm speaking only re: GM cars. Ford and Mopar may be different.

[m22mike]

Kevin
I feel your pain, I personnally do not like Zink plating. On all the cars I have done I am lucky to still get white and yellow Cad done here in Akron at Berringer Plating. Man they do a great job for me, but I really prep well for them.
This first picture of the Booster and MC cover is Zink. Notice the shine. This was done by Steve Gregori in CA. Great job he does by the way.



These next shots are Cad I had done on the last car.





You can tell the finish is not as shiney. The Cad coating is far better for corrosion protection too.

Hope this helped
Mike A

[CamarosRus]

[jl8z28]

I take boosters apart and have them plated and the inside of the booster that has the original plating still looks shiney just like the parts mike is showing, and they are 30 years old.

[Belair62]

Had a feelong Chuck would chime in here !

[Woj]

Zinc is so fragile and the cadmium is so much more durable, I'd do the cad in a heart-beat. If you could see Mike's (M22Mike) work, you'd go with the cad. Just my $.02 worth.

I have also had Beringer's do some black-cad plating for bolts/brackets and the results are very good.

Phil Woj.

[KevinCav]

Thanks for all your opinions on my plating question. The part I am referring to is a bracket that holds the anti-dieseling solenoid. I have a copy of the original GM blueprints for the part and they very clearly spec "zinc" plating for the bracket. The original plating sure does look like cadmium though.

[DaveC68]

Mike,
Your parts look great!
Can you share just what is involved in your "prep work" that gives those results?
thanks,

[m22mike]

Aluminum oxide blast, acid etch with phosfuric acid such as "Ospho" brand. DO NOT use Muratic acid, it is real nasty. Rinse in close to boiling water with some backing soda mixed in Then blow dry with shop air or a heat gun on a terry towell. Rinsing in really hot water gets the stuff dry real fast and keeps the flash rust to a minimum. And keep in mind the plater is going to re clean again but the nicer he gets the stuff the better off your job will come out, there not into doing your detail work.
I will also wire brush alot of the stuff that shows, such as Intake bolts and other bright hardware. It just smooths out the effects of the blast process.
Also on larger brackets and sheetmetal stuff I will use scotchbright wheels in a die grinder to polish up the parts.
Just keep in mind any defects or scratches you can see in the base metal will show up through the plating.
Then bag the stuff in good zip lock bags.

More and more on the new bright Zinc plated junk hardware I buy, I have been stripping the zink off the blots in acid and sending them to the plater for Cad as well. Some of the new Zinc plating starts getting fuzzy as soon as you touch it.

Mike A