One method for resealing hull/deck joint
Hey all,Here's a procedure I got off the Yahoo Columbia message board and used on my 26mkII last summer. Worked good and it's holding up so far. I don't know how others of these joints are made, but if your joint has the rub rail in the center with calk on top and bottom, this should work. It is done from the outside of the boat.Hope it helps...To re-seal this channel, you will need some straight safety razors, a box cutter razor, a pin, a roll or two of masking tape, a small brass or nylon toothbrush with stiff bristles, an assortment of small screwdrivers, putty knives, dewaxing solvent, bleach and acetone or methyl hydrate.you will also need some Boatlife Life Caulk, the flowing one, and a sealant of your choice to go overtop, such as 3M 4200, Boatlife Life Caulk, Sitkaflex, etc. No silicones what so ever! Use a good "premium" sealant, this is a messy job and you don't want to do it again in a couple of years. 3M 4200, Boatlife Life Caulk, Sitkaflex will all last for at least a decade. cut away and dig away as much of the sealant as possible, even behind the rubrail if at all possible. once this is done, mix up a 10% bleach and hot water solution and pour it into the gap to kill off the molds and fungi growing in the voids. Scrub it with the toothbrush.rinse it well and repeat, then rinse again.When this is done, pour in some acetone or methyl hydrate to dry the seam. Let it evaporate away, more than one application may be needed.Wipe the gelcoat and the rubrail edge for at least 1" from the joint with a rag damp with dewaxer. The way to do it is wet and area, reverse the cloth and wipe, then repeat, this will remove most boat waxes from the area to be sealed. It will not remove silicon, teflon or acrylic boat "finishes",..... so if those have been used in the past, you may have a bondproblem.Mask off the edge of the rubrail and the hull, allowing for a bead of 1/4" at least, that means that the tape line is at least 1/4" above the rubrail and there is at least an 1/8" overlap over the aluminum of the edge of the rubrail. Scuff sand this area with a scrap of 100 grit paper and remove any dust.Fill up to the level of the aluminum edge with the flowing Boat Life Life Caulk. This will seep into and fill any gaps in behind the rail. Fill low spots as they occure and pop any bubbles that form with a pin.Pull a bead of caulk over the rubrail and smooth it into a nice slope between the hull and the rubrail, the idea is to have water flow off the rubrail, not pool between the rubrail and hull.Cloth beats paper towels for wiping the excess off the tools, fingers, etc, and acetone cleans off the uncured sealants.You can get a very nice smooth surface, after the sealant has "skinned" by wetting a finger and lighty drawing it over the surface of the sealant.Once this is done on the outside top surface, you can do the same on the inside, but using a mold resistant, acrylic counter sealant, available for a couple bucks a tube at Home Depot or Lowes. This will keep condensation from pooling ontop of the rubrail on the inside and will reduce the "green" meanies from growing up and down from the rubrail over the winter.Sealing the outside underside of the rubrail seems to be less critical. If you are planning to paint the hull or deck, wait until this is done before sealing the edges.