Rebedding a Jib Sheet Track

[sguerrero1971]

I have a 90' Hunter 42 Passage and the Jib Sheet track on the starboard side is letting in a little water. My plan is to pull it up and use Butyl Tape to rebed it to the deck. From below I went looking for where I might gain access to the washers and nuts, but I am met with nothing but nice shiny fiberglass.

I've pulled one screw to see, one if I could, or two if it would just spin the nut I would have to cut fiberglas to get to, or three would it be a wood screw that was just in the fiberglass. To my surprise with a little help from a cordless drill it came right out, but it is a machine screw, so my concern is did I just get lucky and find the one screw and bolt that didn't just spin once loose, or is there a backing plate I don't know about that will fall free when I remove the last bolt, or is it not uncommon to thread a machine screw directly into fiberglass?

Any help would be appreciated.