Here is a pic of the breather tube I just did. It started as about a 6 out of 10 part. Some surface rust, blackened original zinc plating, corrosion etc.
I did a really off the cuff job to see if it would work. My zinc bath was all cloudy and messed up from sitting for a couple of months under the heat lamp to keep it about 80 degrees. And it was too small to completely submerse the part ... so I had to do it one end at a time. Came out pretty nice. I didn't leave it in the acid long enough so I had some tiny bit of residual rust that I had to wire brush off (brass brush) in the middle of plating. Had a few areas that must have been contaminated so it didn't take well the first plate ... pulled it, cleaned it up some more, plated again.
My object was to see just how lazy and incorrect I could be and still get a decent plate. Seems like the zinc molecules basically want to do the right thing no matter what. With the bath in bad condition it seemed to want a voltage around 1.4vdc .... typically the better the bath solution, the more volts/amps you can use because the bath transfers the zinc more efficiently. With a not so good bath it wants to go slower and too much power will form the large zinc crystals witch cause the "shadowing" and a rougher finish.
