C
Chris Stevens
Guest
Problem with repairing any sort of surface damage to GRP (notwithstanding it might only be very minor), is whether or not the material used as filler is going to adhere to the layup or not.
Old GRP will in almost all cases be chemically inert, if scouring with acetone softens the surface, then repair with flow-coat (with filler material added if required) is probably the best way to go, as there will eb some degree of cross linking between old and new, which will greatly reduce the chances of cracking.
If acetone scouring does not soften surface, then careful mechanical abrasion and filling with some sort of epoxy based material is probably the best option. Polyester body filler is not something which is going to adhere particularly well, and like thin coatings of epoxy primers, is likely to mean cracking is much more likely in future. Essentially repairing surface damage to GRP is not that different to sorting osmosis on marine GRP, and there is much accurate info covering that on the net.
Old GRP will in almost all cases be chemically inert, if scouring with acetone softens the surface, then repair with flow-coat (with filler material added if required) is probably the best way to go, as there will eb some degree of cross linking between old and new, which will greatly reduce the chances of cracking.
If acetone scouring does not soften surface, then careful mechanical abrasion and filling with some sort of epoxy based material is probably the best option. Polyester body filler is not something which is going to adhere particularly well, and like thin coatings of epoxy primers, is likely to mean cracking is much more likely in future. Essentially repairing surface damage to GRP is not that different to sorting osmosis on marine GRP, and there is much accurate info covering that on the net.