Have been putting in the research into the realm of fiberglass repair. I have a grasp on different resins and materials for doing the repair. Trouble I’m finding is how to identify what materials were used on previous repairs or factory materials? How do you know what was gelcoat versus two part paint? Poly resin versus epoxy on the original part? Understand epoxy is generally the universa go to for repairs but would like to be able to tell when poly can be used.