Sorry to dig up an old thread, but I do believe it is relevant since I am using this same zinc plating recipe from grepper. Thanks for the excellent writeup by the way.
Now it says that you "may have to repeat to get a good coating". I am using a variable power supply and it is putting on a nice even coating first try. So is it necessary to wire brush and run through a second time.
Also why 5 to 10 minutes?
Also the copper wire is getting coated as well this is a real pain as I got to clean the zinc of with a sanding sponge. Anyone who things this is not durable has another thing coming. It really puts a nice thick coat on there.
If you're applying too much current, it will seem like its coating pretty fast and thick. This is exactly what you should be avoiding because, at least from my hands on experience, once dry it will fall right off. The part will look shiny but don't let that mislead you. Every single missed spot will show up immensely clear when/if you do a chromate conversion after.
If your parts are getting done, thick withing 10 mins, then something is wrong, this is a very slow and boring process. For some pieces, the first round will seem like it got full coverage, but once you clean with steel wool, there might be missed spots due to any of a number of contaminants and such, so a second or third try may be necessary. I've had good luck with larger parts on low voltage left alone for a long time, this is the only way I managed to get an even, full coverage in the first try. There are some pix in my build thread, check them out. I've finished the blue and yellow chromate conversions too, and glad its over
To avoid having to clean the hanging wire, don't strip it entirely, just at the two ends to make contact on the copper pipe and at the part, see my tank pix attached here.
