Hi Marc

I usually blast everything first then quickly go over the parts with the wire wheel to get them smooth.

If you left them blasted, the zinc would be dull and more of a pale yellow due to the course of the part.
This also happens when the metal is very badly pitted because you cant get it smooth enough.

If you run them over the wire wheel this will smooth them out and make the part come out a perfectly deep yellow.

All depends how good the mix is too

Hope this helps

CheeRS

Chris