Thanks, Rick. I wouldn't have thought something as relatively inert as mineral spirits would attack cured silicone. I'll bet it only works on uncured stuff, but will sure give it a try. Thanks!

Btw, and to add to the thread above, we have Beckson style inspection plates in both bulkheads of our AT14 (no hatches), and they work great. A big one in the rear allows loading of limited stuff for a day-play boat. I cut down the attachment flange to make the plate fit. The front one's as small and light as possible and used only for ventilation and checking for leaks in the bulkheads--which are plentiful, as it turns out, hence my question about redoing the attachment and getting rid of the silicone. All in all, the boat is very uncomplicated, and, at 35# fully rigged, pretty light, which pays off every time we use it.

--Scott