If anyone is interested in doing their own zinc plating, it is fairly easy to do, and quite rewarding. One more part of a restoration where you can say "Did that myself!"
I purchased a zinc plating kit from Caswell Plating, and have had excellent results.
I went for their 5 gal. "copy cad" kit. It really just does zinc plating, with the option of several chromate follow on treatments to give the zinc plating the look of the various cadmium platings. Real cadmium plating is toxic, and typically given a yellow or other colored chromate treatment. If zinc is what you want, you don't need any of the follow on treatments, so the copy cad kit does just what you need.
The kit had everything you need except the water! It includes two heater elements, a thermostatic control, zinc anodes, chemicals for the plating bath and also for a cleaning bath. The only additional thing to buy is a power supply. I purchased a 3 amp supply which was just large enough for all the plating needed for a 350 with the exception of the rear sprocket. That required assistance from a 12v battery charger.
Before plating it is necessary to have the parts completely clean. That means all dirt, oil, rust, corrosion, or old plating should be removed. Most parts got the following treatments depending on condition:
Dirt and grease removed with parts cleaner.
Significant rust removed by electrolysis, followed by 10-20 minutes in 5% Hydrochloric acid.
Very light rust removed by acid rinse or wire brush.
Old zinc plating removed by 5% HCl as above, as long as required to remove all old plating.
Be sure the parts are clean.
Sand, file, or polish as needed to remove any pitting or other surface damage. The plating will not disguise rust pits, scratches etc. Your part will look exactly like did before plating, except that the surface will be bright and shiny zinc. If you put pitted, scratched parts in, you will get bright and shiny pitted and scratches after plating.
Once prepared, parts were strung up on copper wire, then placed into the plating bath, set up to the time, temperature and current recommended by the kit instructions. Plating is the quickest part of the whole process, taking just 20 minutes in the plating bath. As with many things, preparation is the key, and the hard part.
The 5 gallon bucket I used for plating was a good size, able to fit everything I needed to plate. The 3 amp power supply was just barely big enough, but it got the job done. I had to do a few larger items one at a time, since 3 amps was just the right size for one axle at a time. I could do a dozen or so small nuts and bolts at a time, as many as I could string up at once. For the rear sprocket, I used a 6 amp battery charger, in combined with a 6" length of toaster wire for resistance.
Overall the results were like magic! Old rusty parts came out looking Bright and shiny, just like new!!
The kit was relatively expensive, I'm sure I could have gotten all the parts for my 350 plated for less than the total cost of the kit plus the power supply, but it was both educational and fun to learn and plate all the different parts.
If anyone has questions just ask.
BS Mechanic,
Bob H.
