I second the opinion that a simple moisture meter is insufficient to dictate the severity of decay and extent of repair . The readily accepted method of sealing penetrations is to drill a hole for your fastener 1/8" to 1/4" larger than the circumference of the fastener. Then use a bent nail to dig out the core from between the fiberglass skins. Plug the inner hole and then inject thickened epoxy. Once cured, you drill the proper sized hole for you fastener. If you remove the fittings near the high moisture areas AND you can dig out all of the rotted (black) core, then I would say you are good to go. It's frustrating to destroy a perfectly good looking deck chasing core rot.
Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Nov 8, 2016 10:51 AM, "Robert Mazza via CnC-List" <cnc-list@cnc-list.com> wrote: > Ryan, > > The first thing to do is remove the track and determine the type of core > in the deck. If a C&C I expect it is balsa. If that is the case, then > determine if the core has decayed. That is, is it brown mush. If not, and > the core is still pristine, but has a high moisture content, you may be > better off leaving it in place and "potting" the fastener holes to prevent > the entry of water. Water in most likely entering the balsa through the > fasteners and migrating through the kerf system (the cuts in the core to > make it flexible). > > Balsa core that merely has a high moisture content, that is up to 20%, > still has very high physical properties. Remember that balsa starts with a > moisture content of 12% at which it has the highest physical properties. If > you cut off the source of the water by "potting" the holes, the moisture in > the core will gradually dissipate, and without access to oxygen it will not > decay. > > I've seen too many boats undergo expensive and damaging repairs of balsa > with merely high moisture content, but no decay. I was with Baltek Corp for > eight years and we did a lot of research on the properties of "wet" core. > Balsa will only absorb moisture to the moisture saturation point, which if > memory serves me correct is about 26%, at which point the physical > properties stabilize at about 80% of the original properties in shear and > compression. Since balsa has substantially higher shear and compression > properties than foam cores traditionally used in decks, it is more than > strong enough for the application. However, the key is decay. All decayed > core must, of course, be removed. > > Just something to think about before you consider major surgery. > > Rob Mazza > > On Tue, Nov 8, 2016 at 9:21 AM, Ryan Doyle via CnC-List < > cnc-list@cnc-list.com> wrote: > >> Hey all, >> >> A survey on a boat we are looking to buy turned up some elevated moisture >> readings on the port side under the genoa track. I would do this repair >> myself as I understand what needs to be done, however my wife is insisting >> I leave this job to a very experienced professional. >> >> In the affected area I need someone to remove the deck skin, remove the >> moist core, and replace the core in a 2'x6' area except under the stanchion >> base and genoa track where I would like it to be replaced with solid >> epoxy. Then finish the job nicely. >> >> Does anyone have any recommendations for work like this? >> >> Thanks in advance, >> Ryan >> >> (Former 30mki owner) >> >> >> >> Sent from my iPhone >> _______________________________________________ >> >> This list is supported by the generous donations of our members. If you >> wish to make a contribution to offset our costs, please go to: >> https://www.paypal.me/stumurray >> >> All Contributions are greatly appreciated! >> > > > _______________________________________________ > > This list is supported by the generous donations of our members. If you > wish to make a contribution to offset our costs, please go to: > https://www.paypal.me/stumurray > > All Contributions are greatly appreciated! > >
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