I am blocking the primer surfacer on my project. I have located a few low spots. Nothing major I am just going to lay another two coats of primer on the spots and reblock those area's. My queston is in the low spots there is some remaining guide coat (Run of the mill rattle can) Do I have to remove the guide coat from these low spots or can I prime right over it and reblock. I am using 2K urethane primer and I know the Rattle can is Laquor based. Any Help?
If in doubt sand it off,safe as opposed to sorry.Different products generally dont play well together and the lacquer isnt as strong as the urethane(bond wise)Could cause future problems.
For future reference:The best guide coat is to tint your first couple coats of primer a different color from the stuff your going to lay over it to block out.That way when you cut into it,you know how much paint thickness is left before you get to bare steel or the sub strate you are working on top of.It will also show your low spots just like the guide coat would.Good luck.
