Although metallic threads do not require the use of CP, it would not hurt the final finish even if you did use it. It will seal the thread wraps and prevent those nasty bubbles from appearing when epoxy is applied to the wraps. Without CP, you may get a bubble dilema. When I build a rod where I want to retain the thread colour and nylon thread has been trimmed with nice metallic trim bands, I always coat the entire wraps with CP, using 2 coats of 50/50 mix.......1/2 CP with 1/2 distilled water and 1 day apart to allow for complete drying time prior to finishing. Everyone has their own little tricks to a good finish and this is just my way of completing perfect finishes each and every time. Good luck and have fun with your rod project