Mepstein, I agree, Shaun’s work is beautiful and if you’re doing a batch of parts it makes sense to ship them out. I don’t believe, for a moment, that I can duplicate a pro level finish in my home shop. That said, I still think a DIY setup is perfect for those random, single or multiple parts that crop up in the course of a restoration. Particularly where rust protection and expediency trump ‘pretty.’
Here are some notes on my recent plating experiments. Just FYI stuff.
I continue having great success with the white (silver) zinc application. I’ve learned to better regulate the voltage/amperage to get good coverage, based on part size and/or batch size. I’ve also settled on doing at least three ‘strikes’ on every part. That is, the part goes into the electrolyte bath three times, with rinsing and polishing in between each dunk. Sometimes I do four strikes, but there seems to be a point of diminishing returns. Still, it takes at least three to get enough zinc on the part to give it a deep, ‘buttery,’ finish.
Zinc solution – No difference between the Caswell kit and DIY chemistry posted here:
Zinc Plating with Common Materials
This may be controversial, but I’ve made mutiple batches of electrolyte using the Caswell kit and the home brew ‘grocery store’ recipe outlined in the link. Truth be told, I get better results with the ‘home brew’ but the Caswell kit works fine as well. YMMD.
Chromates – No Joy!
I have not been successful with the chromates -- black or yellow. I’ve had some success getting full coverage with the black; but my yellow is consistently splotchy and partial. I’ve used the proper Caswell chemistry (including brighteners) kept everything as clean as I can make it, adjusted temperatures, and followed the instructions correctly.
There must be something I’m doing wrong, but discussing this with Eric at PMB, we can’t figure out what it is. I put this up here, so if others are having trouble with the chromates, they’ll know their not alone. Maybe good chromate application is a little beyond the average DIY guy, like myself.
I don’t see my lack of success in the chromate step to be a major drawback. The electrolytically driven silver zinc adheres really well and provides most of the rust protection. Many Porsche parts, including the oil lines I just purchased, came zinc plated; but without the yellow chromate.
My interest in plating is focused on ‘quick and easy’ – what to do with those random, rusty, incidental parts that crop up in the course of a project. In those cases, most of the time, the black or yellow chromate, final coat is not critical.