Stop That Leak!
Modern chemistry has presented us with new choices of sealants for everything, including the kitchen sink. The trick is to choose the right one and apply it correctly. Here are some hints on application:
– When trying to form an even, good-looking bead with polysulfide, coat your fingers with liquid detergent and you can mold the sealant, after it skins over, without sticking.
– Most pros pull a bead of caulk because of the control it offers. A good bead in the first place is better than the finger and detergent approach described above.
– Polysulfides cure faster when wet. To speed up curing, adjust hose nozzle to fine spray and keep sealant damp. For smaller areas, use a spray bottle.
– Sometimes a primer is needed before applying sealant to some surfaces. Read labels carefully so you can buy needed primers and solvents before leaving the store.
– Its best to avoid caulking in cold weather. Both the caulk and the boat should be in moderate temperatures for the best result.
– Use underwater caulk on through-hulls to insulate, not just against leakage but against galvanic corrosion.
– Marine polysulfide sealants help keep engine mounting bolts from corroding or vibrating loose, and ease future removal. Put some on the threads before turning the nuts down.
– If you carry an extra tube of marine silicone sealant aboard, you can jury rig any size gasket.
– When making a hatch gasket from silicone sealant, place a bead on both surfaces, then cover with waxed paper and close hatch. Paper keeps gaskets separate as they cure.
– Coat back sides of light fittings to seal wire ends (but not light bulb socket) to prevent corrosion.
– For proper adhesion, seams in teak decking should be at least l/&I-inch wide, l/4-inch deep.
For more information on choosing the right sealants and how to apply them, purchase This Old Boat, Second Edition today.
