Deck has a "crunchy" spot...

[theBotanist]

Hello everyone,


I noticed within the last couple months or so a kind of crack forming on the sailboat deck, followed by the area around the crack making a fiberglass "crunching" noise when stepped on. Thinking that the issue might have something to do with water intrusion, I drilled a couple of 1/4in inspection holes to assess the condition of the wood underneath, only to find that the wood seemed dry and in good condition. I'm not really sure what might be happening here (deck problems and repair is something I'm completely new to), but I am assuming if it isn't properly dealt with soon it could get worse (and possibly lead to water intrusion). Has anyone experienced anything like this? If so, how did you fix it?


Also, on the same note, what would be the best method to fill in the deck holes I had to drill? I've heard of people using Marine Tex or epoxy covered by a matching gel coat; is one recommended over the other?




Thanks for the help!

[catsketcher]

Gday

It sounds to me like the deck has some delamination with the core. I don't know a good way to reconnect the core to the skin but if it was me I would try using vacuum and sucking pretty thin epoxy through a few holes in the area. If you ask around you may find someone with a vacuum pump or you could use a venturi and air compressor. You also need some special vacuum tape which is really sticky and great at sealing air leaks.

So a quick break down - drill a few holes in the under deck skin. Seal some tube into the holes and connect tubes to single line that has cheap plastic stop cock. On upper skin side drill holes over all of the crunchy section. Place a length of old rope all waved around the area. This will act to let the air through. Then place the vacuum hose, leading to the pump or venturi, in the rope and use plastic and the sticky sealant tape to hold the edges of the plastic down.

Then turn on the vacuum. You may need to use a vacuum cleaner to get the bag down at first then switch to the venturi when you have located all the leaks and sucked out most of the air. Then put the hose underneath into a container of very slightly thickened epoxy (thicken with microfibres but it still has to be very runny - use slow hardener and keep it warm). Turn on the stop cock and the epoxy should flow into the holes and into the voids in the laminate.

If this seems too hard then you could just cut off the top of the deck. Remove and replace the core and then epoxy the top skin back down again.

cheers

Phil

[psk125]

Sounds like catsketcher has done this before.

[tkeithlu]

The vacuum is the right way to go, but may be overwhelmingly complicated or equipment intensive. Consider multiple holes top and bottom and then forcing the epoxy in from the top. Also consider cutting out either the top layer or the lower layer of fiberglass, cleaning out the core, and then putting in layers of cloth and epoxy in place of the core.

For a small hole, 3M 5200 will seal it up; MarineTex would work well for a larger job.

This is a task that you best not ignore - the designer figured on that deck being part of the rigidity of the hull and support for the mast. Good luck with it.