CORE REPAIR (Lessons Learned)

Mark Whipple, #59, Tikva

I wanted to pass along some the discoveries I made on my boat to those thinking of doing a deck recore. The price savings on large quantities of polyester are tempting, but just make sure you use the materials that are most appropriate to your job.

When I bought #59 I was told the deck was recored by a boatyard that specialized in building small sailboats. They probably had lots of polyester around since polyester is better suited to laying up new construction than epoxy. While disassembling my boat I discovered two notable problems: while removing some of the stanchions a layer of fiberglass pulled off in spots, and there was a small (>2") tear on the foredeck through the top layer of fiberglass. Both seemed unimportant at the time.

The tear in the fiberglass turned out to be a big problem. The foredeck had not been recored (only the side decks), but four 1 1/2" holes had been drilled through the top skin and core of the foredeck, probably to pump in resin. The resulting plugs of polyester were only covered with a single layer of fiberglass cloth which also covered the entire deck. They laid up that cloth right over the old non-skid! The plugs did not adhere well to the surrounding core and skin (I popped them out with a screwdriver). One plug split and flexed over time, tearing through the top layer of cloth, allowing water to saturate a 4' x 2' section of balsa core.

Beneath the stanchions and up near the stem, the cloth was so poorly adhered I could pull it up by hand, even though the fiberglass skin underneath had first been ground down in those areas. There are several other repairs done by these guys where the cloth applied with polyester came off as easy as Fineline tape. On the foredeck I've had to grind away blistering where water had begun to penetrate the top layer of cloth. I suspect I'll be monitoring this situation for years - unless I decided to grind it all off. As a preventative measure I ground off the top layer wherever I was mounting hardware, and covered the area with cloth and epoxy.

While I question some of the repair techniques used by the boatyard, I would have much more confidence in their repairs if epoxy had been used. Epoxy bonds better to substances like balsa, Nidacore and the top skin of the deck. It is more impervious to water penetration. I also like not having to wear a mask whenever I'm repairing fiberglass with epoxy, because even the smell from picking up a closed container of styrene bugs me.

Whatever you decide, share the results with this list. We are each others' best resource for information and encouragement!

I'll try to post some pix someday - I'm too busy fairing at the moment! At least the worst of the grinding is over. I finally bought the paint this weekend!