Copy Cad Zinc Blackener
This is my first post on the forums, so Hi to you all.
I'm having difficulty achieving a black finish on a zinc workpiece. It was previously phosphated, and I have stripped it back to the metal using Birchwood Casey Blue and Rust Remover (Sulphuric and Phosphoric acid based), and steel wool. I have previously treid using Birchwood Casey Aluminium Black, which does impart a truly black finish to it, but often turned out patchy, as you do not get enough solution in the bottle to immerse the part. So I bought Copy Cad Zinc Blackener, and following the instructions, made a 10% solution. I thoroughly scrubbed the part using the Blue and Rust remover and steel wool, and then rinsed it thoroughly and placed it into the Copy Cad solution for 5 minutes, agitating the part. I then removed it and rinsed it throughly, and left it overnight. I even tried degreasing it after rinsing it - the finish I get using this method is only a dark brown, even when I seal it using WD40 - what am I doing wrong? I'm convinced that I would get a nice deep black if I sandblasted the part with aluminium oxide grit, but I don't have acess to a gritblaster of any kind. Can anyone recommend a better way of pre-treating the metal to get a better finish please?
Your help will be very much appreciated.
Gary
|