Resin coating in vacuum for zamak parts to be chrome-plated

Information please!

We chrome-plate a hollow, cylindrical zamak part and heard about a method of preparing the part through resin-coating it in vacuumn, thus covering small pores, etc. Supposedly only light buffing is necessary before beginning the actual plating process.

Can somebody inform us about the method and about possible experiences with it?!

Thanks, Andreas

Impregnating castings does help seal the pores and provide a better layer for plating. It will require a capital investment for the equipment and you will have to modify your preplate cycle to activate the resin coating. Most suppliers will run a few samples for you to compare with non-treated parts. Most of the applications I've seen it used for are high end castings for fuel dispensing or to prevent gas migration around a seal. If you're trying to just eliminate a few polishing operations it may not be the best alternative.