For periods longer than two to three weeks (depends on local conditions) you want antifouling paint. Specific type depends on what others in the same location have found works well - some paints work great at one place and not another. Whichever you choose make sure it works for trailerable boats: meaning it can be left out of the water indefinitely. Many paints lose effectiveness after a few weeks to a month. You need to drop the centerboard and then antifoul the boat and board. The trunk really doesn't need paint as with the board in and leeching biocide & herbicide and little/no light growth isn't an issue. As you can reach a few inches into the truck it doesn't hurt to prep (ie, recommended sanding based on the paint supplier) and antifoul. Concerning water getting into the steel ballast in keel and centerboard. The usual way water gets in is through damage to the shoal keel and centerboard's shell. Any location with damage repair using fiberglass and epoxy. Next look at the seam that runs along the edges of the centerboard. Any cracking along the seam is suspect and should be fiberglassed and epoxied. Next look at the seam along the bottom of the centerboard trunk and the keel. (Talking exterior here not where the truck goes through the cabin sole.) This is where the trunk was placed against the bottom of the shoal keel (before the ballast was poured into the keel). This butt joint was fiberglassed on the inside, then the outside smoothed with thickened resin and gel coated over. Any cracking needs to be repaired (again epoxy resin). Don't make the centerboard slot smaller as the board will not fit - clearance is only 1/8" or so on each side of the board. Barrier coat is a personal choice. If the boat will spend the winters out of the water I'd consider no barrier coat.(example: my M17 SWEET PEA spent spring/summer/fall in Puget Sound on a buoy and on trailer winter has no barrier coat and no blister problems.) Follow the application recommendations for the products you use _to_the_letter_. Shortcuts lead to adhesion failure and generally not working like it should. Tyler, let me know if anything is unclear. :: Dave Scobie :: M17 #375 SWEET PEA - m17-375.com :: M6'8" #650 :: SV SWALLOW - sv-swallow.com On Mon, Apr 8, 2019, 9:37 AM <casioqv@usermail.com> wrote:
Does anyone have information on mooring an M15 long term in seawater? Is it feasible or will it cause major damage? My boat has a lead centerboard, but iron in the keel. I have added epoxy, cloth, and gelcoat to the trunk liner-hull seam to hopefully seal it better.
I suppose if I were to moor it, I would pull the centerboard to put anti-fouling inside the trunk, and on the centerboard.
Sincerely, Tyler '81 M15 S/V Defiant #157