I have done several marbeling jobs with good results. I am doing my first marbeling on the actual guide wraps. I'm using white CP thread . Do I need to add a coat of CP on the wrap before proceeding with the epoxy and marbeling ? Thanks in advance for your advice.

If you are saying NCP thread I still put CP on just to be sure the color stays

Bill - willierods.com

It's a matter of choice, you don't have to. But as bill says it helps to retain the colour. since your going to marble over it i dont think it matters. I only use cp on ncp thread if im doing a weave or dec wrap, i dont use cp on ncp on guide wraps, i always put on a thin coat of finish.

If you will have significant area of white thread showing you need to use multiple coats of CP on the thread before applying epoxy. Unless you are using a white blank or paint white under the thread before wrapping. White is very difficult to get a uniform, real, white color. You might try a test winding on a blank similar to what you are going to use. Pack the windings very tight also. Light colors on dark blanks are very challenging.

Also D NCP with CP is also a good idea

Bill - willierods.com