Re: 5200...the devil????
Hermit-
The problem with 5200 is that it is too strong and inflexible an adhesive sealant for most things on a boat. If the part is something that is highly loaded or moves a bit, you want a sealant/bedding compound that can stretch and flex a bit more than 5200 does. If the part is something that might need maintenance, repair or replacement, then 5200 is too strong to use, since you can often damage the underlying fiberglass trying to remove something bedded with 5200. The adhesive strength of 5200 is often higher than the tensile strength of the laminate itself.
BTW, when you rebedded your chainplate, I hope you checked the deck to see if the core material was sealed, if the chainplate passes through a cored section of deck. If not, and you have a leak in the future, taking it apart to correct it is going to be a gold-plated b!tch, and the deck will likely start to delaminate there.