My wife has done a really nice graphics job on her old glass/polyester 5'6" surfboard with Posca water based pens. She initially covered it with spray on laquer which was suggested by the shop (a grafitti shop) as sufficient to protect the graphics.
Now after a couple of weeks of hard sailing it is obvious that the laquer is not sufficient. The graphics start to come off on the rails and there are scratches where the board has touched the sand/rocks on the beach.
What I would like to do is to add a layer of polyester on top but I am not sure if this is compatible with the Posca or the laquer. Will the colors bleed or can this work ? Alternatively if anyone can suggest another type of protective layer (preferabbly with a glassy finish) that will protect the graphics.
I am not an expert on coatings but I imagine you can get some sort of clear sealer that will stick to the water based finish and also accept a solvent based top coat. Maybe visit a good auto body or marine finishing shop and they might have solutions for you. Good luck and hope you can preserve this beautiful artwork!