17prospective buyer

I have disassembled the engine bay/fender area of the car pretty well, and want to replate the fasteners/components that were originally cadmium (i think) plated. Cadmium seems to be fairly hazardous from a health and environmental view, so alot of places won't do it around here in Ontario. But, there is a place in London called Precision Plating that will do brass, copper, gold, nickel, tin, zinc, zincate, etc.

I think yellow zinc plating would most closely get to the original look, but would corossion resistance be noticeably worse? Or would the parts last another 25 years before the substrate starts to corrode/oxidize. I think cadmium is the best for corosion resistance, but catch 22 situation, it's also the worst for environmental/health damage goes.

I also was wondering about plating some other parts that weren't plated from the factory, such as the ABS/PS resevoir bracket, just for the nice look and durability of a plated finish.

Prep surface finish would be a consideration as well, i would be sandblasting some larger parts, is the texture produced by blasting desirable for plating the substrate?

Leon Speed

Yellow zinc is fine. I assume they will not 'last' 25 years just as the cadmium plated didn't last 25 years - those also oxidize when not covered in oil or grease. Why would you be prepping larger parts? Just hand the whole bunch to the platers and pick it up nice and shiny.

JHowell37

Young man, are you planning to take this car to Concours events?

17prospective buyer

Hell no, too many KM. The red crossmember should give it away. I just think the yellow plating looks so nice in a clean engine bay. Sometimes there isn't anything like stock.

dr bob

The zinc won't last as long as the original cadmium, but that's always subject to what it's exposed to and for how long. The cad looks bright until it is no more, while the zinc dulls almost immediately on exposure to acids and salts. If you'd like either of them to stay bright longer, clear-coat them lightly after plating.

For parts that were not previously plated, give them to the plater and let them do the cleaning/stripping/prep. Solvent degrease them for sure, but no abrasives and no blasting. Sandblasting will pit the metal and affect the finish. The plater has to do all the prep steps anyway, even it it's just to guarantee that your slimey fingerprints don't ruin their work.

Last but not least, replating is a slippery slope, in that everything you don't plate will stand out. If you go down this road, plan to disassemble EVERYTHING that you can see in the engine bay. Similarly, you can't do just a few suspension fasteners, etc. You will end up doing them all eventually once you start. Platers here charge by the lot, so your plating job big or small will cost about the same.


Pics before and after of course...

17prospective buyer

Thanks Bob, i actually thought about the surface finish that sandblasting produces right after posting and how thin plating actually is (less than a thou) and maybe you could change the appearance of the plating by changing the finish of the substrate. But i will take your advice and just hand it over.

This whole car is a slippery slope... if i had the money, i would disassemble the entire car and reassemble it like it was done in a factory, so it was virtually brand new...

Hilton

Also watch out for hydrogen embrittlement of high-tensile steels.

Its not generally regarded as an issue for most of the stuff on a 928 (8.8 grade), but there are a few higher grade bolts in the suspension (10.9 grade) for which it may be worth investigating bake cycles etc.

Rob Edwards

Here's a datapoint-

February 2009:

Before:



Blasted:



Plated:




Fast forward 4 years: The car has only been driven maybe 3000 miles since then, never in the rain. That bracket (and all the plated stuff) is still shiny, but there does seem to be a bit of surface dulling that has occurred. Same with all the other hardware that I had plated.

So it has _sort of_ held up, but I think it's going south faster than the factory plating did.

Ad0911

make sure you have a list of all components you send out to the platers, including a picture of the parts nicely sorted so you can see if it's all there when you collect the stuff. BTDT

Bertrand Daoust

Yes take some pictures before you send all the parts.
And leave one to the plating shop. That's what I did.

+1 on what Rob said.
I did some plating about three years ago. In two batch.
The second batch did not hold as well as the first. Why?

Before and after plating (part of the first batch).

M. Requin

Bertrand, what material did you plate your hardware with? TIA!

Hilton

Bead blasting is a good prep for zinc plating and its non-destructive too..

but..

Be VERY careful blasting or using a wire wheel on the factory cadmium-plated bits. Cadmium is NASTY stuff and you do not want to inhale it.

If you don't have suitable dust-extraction/separation facilities and a means to dispose of it safely, its one best left to the pro's.

Tom in Austin

Plating is great for us OCD folks. Does anyone know, were the door hinge fasteners plated? For some reason I'm thinking they might have been painted, but more recently I think the doors were painted separate from the body ... I may plate these bolts and washers anyway on my next order ;-)

Ad0911

The company that does the plating can do the degreasing, chemical paint removing and chemical derusting as preparation to the plating. It is all in the price. Having all of this done in one go is the most economical way of doing all this work.

Bertrand Daoust

Hi Martin,

It's zinc plating.