Zinc or Nickel?

[mcguijo]

I posted the following on the Tools forum but had a recommendation to post on Triumph Forum instead. . .

Re: Caswell Copy Cad/Zinc plating kit [Re: Britishtools]
#139855 - 10/18/05 08:17 PM

This is perhaps a real silly question. .but my eye is not trained enough to tell the difference between something zinc plated and something nickel plated. Most of my engine pieces on my TR3 have a good enough coat of rust on them that I can't tell what they were coated with originally. I'm going to guess most screws, fasteners, and what not were zinc plated. Any insight?

 

[dklawson]

In general, zinc plated parts are silver to silver grey depending on the degree of oxidation. Nickel plated parts typically have a "warmer" appearance and the coating is "smoother". The nickel is also silvery but can have a slight yellow/brownish color. However, the final color often has a lot to do with other elements in the plating.

I suspect most engine parts that are/were plated will be done in zinc as it is a much less expensive process. Zinc can be deposited directly on top of steel. Nickel plating usually involves a flash coat of copper over the steel first so the process is more expensive. Electroless nickel plating doesn't necessarily involve the flash copper, but I don't think it was a common process when TR3s were built.

I've been told that a cost effective way to handle this is to collect a large "lot" of fasteners you want plated and send them in bulk to a local plater. They will charge you to plate all of them as a lot instead of per piece. I've not done this myself so others will have to comment on whether this is true.