Resin Injection to Repair Hull?

[c1287n]

My 32' fiberglass sailboat broke free of its mooring this past fall, with resulting hull damage on the starboard side. The gel coat is cracked in three places above the waterline from impact with rocks, however I don't know the extent of hull de-lamination. What is the best procedure by which I can properly repair the hull? How can I check the extent of de-lamination? Is it possible to inject resin under substantial pressure (or vacuum) to fill voids between de-lamination? The boat is in my workshop awaiting repair.

[Jollydog]

Is this a cored hull or solid fiberglass? What is the approximate age of the boat? You stated that you can see the cracks in the gelcoat, can you also see them on the inside of the?

The first step is to deterime the extent of the damage; are the cracks just cosmetic and localized to the gel and skin coat, or do the cracks continue into the laminate? You may need to grind away some gel coat to determine this.

[c1287n]

Thank you for writing. The boat was manufactured in 1979 and is a solid, half-inch thick, fiberglass hull. I have taken a core sample directly from what appears to be the worst damaged area (a splintered 3" crack at the waterline), finding little evidence of substantial de-lamination. However, there appears to be a 6" separation in the outer layer of cloth inside the hull, adjacent to the major point of impact. The outside of the hull suffered numerous digs and scrapes through the gel coat, although none indicate anything too serious structurally, other than the area I have described above.

My main concern is determining the extent of internal hull de-lamination, and then repairing it to where the hull is again as strong as it was originally. At one of the boatyards they suggested that I inject a dye, then grind out all layers stained with this dye, building a completely new hull in this area. I am wondering if there are better methods for repair, for the outer hull profile remains perfect now. I assume the superficial digs in the gel coat can be filled, and the hull sprayed with "Awl-Grip" paint, or something of the sort. Having little experience with such fiberglass repair, I am exploring whatever options there may be.