From my experience it can happen that fiberglass fibers break and if there are two breaks there can be a dent. Pounding with a rock is hilarious! That means you want to weaken the rest of the fibers that might be intact?
Its happened that I have folded a composite boat 70 miles from the end of the trip in NE Ontario. Duct Tape to the rescue. I am lucky there was no hole. Another time in Wabakimi a fast slam into a rock that cracked the foam core and bent the gunwales. Thankfully no hole.
In mild whitewater have put a crack in the glass and gel coat of one boat. No dent.
So who cares if its dent or crack? You are certainly angling for more extensive repairs if you use a rock to mash all the remaining fibers and resin. Better to duct tape and live with the misshape.
Paddler's Truck Rack
Pull-Up Strap Handle Kit
|Table of Contents|