: I installed a skeg in my cedar strip kayak over the winter and just tried it
: out yesterday, only to find that I have a leak. After about half an hour
: in the water I got about a quart of water in the rear compartment.

Just a thought -- as I had a similar leak on a sailboat centerboard box-- when epoxy is applied to a relatively cold assembly, air tends to be trapped in the joint and as the warm/hot epoxy sets, the heated air bubbles out creating a sort of blow-hole, enough to start a small leak. I fixed the fault by warming up the joint before applying the epoxy. Any way this is now after-the-fact!!

As suggested in other responses, slosh some water , with maybe a little washable dye to identify the source of the leak .

Cheers

Prasad