Issues in Cadmium plating with yellow passivation

Q. Sir,

We have a project where material should be Cadmium Plated to a minimum thickness of 12 microns.
We have the following queries.
1) Finish bores are to be masked from cadmium plating process.
2) Baking is done for 190 degree for 8 hours; can baking affect the bore to be masked?
3) Can masking solution withstand 190 degree for 8 hours - please suggest a solution.
4) Is there a need of nitric acid dip before baking & after baking for brightening purpose.
5) 7 feet long shafts have black stains; how can it be removed in cadmium plating?
6) Is it necessary to recoat Cd plating after baking?
7) Suggest how to achieve uniform coat of Cd plating.