Inside of a centreboard case
you really need to clean the old glue off.....thats whats given up ....so all you are doing is epoxying to old glue on one side....the old stuff needs to come out, cut down (broken )hacksaws is a good start if you dont have a dremel....
Bell Woodworking used to use something called "Danboline" for the inside of centercases and tanks. It was reddy - brown when fresh and went darker with time. It was very good stuff!