Hey guys, long time no post. Thought I would chime in here since this topic seems to come up a lot. Here is the way I repaired leaks in the seam of my recently aquired Swordy (thanks MCImes). My goal was to make this a quick and easy 1/2 day project.
First: Dry out your boat!
Second : Gather the necessary supplies for the repair, I am using a variety of composite products here: Due to the rigidity and and stiffness, I chose to use Carbon fiber tape (vs fibergass) that I had bought for repairs on my old ski. I thicken my epoxy with colloidal silica and colored it with black graphite powder that gives a nice smooth glossy finish and UV protection.
Third: Identify leaks. Some were pretty obvious due to salt crystals at leaks, but did leak test any way. Only want to do this once. Pressurize hull with your lungs and plug vent/drain etc. Spray hull and areas most likely to leak with soapy water.
Next: Clean areas to be patched with acetone. Double tape area and sand moderately.
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Here's where I skip typical steps, Cut carbon to fit inside taped area. You wont be able to see seam with black resin to cut with razor, which I ended up having to very carefully do anyway, but, not to much., Apply a thin coat of the slightly thickened epoxy to fill the uneven surface and apply carbon strip. Saturate carbon (or fiberglass) with epoxy, I use throw away brushes. Next, to avoid the typical sanding and finish coat. apply wax paper and thoroughly smooth with dry brush then squeeze out excess resin with your hands. I actually created a vacuum by sucking on the vent tube and plugging it to help draw resin into the seam.
Let it dry, BUT, not fully cure. About an hour and a half or two in the sun with regular cure or what is commonly referred to as slow cure. All relative. I some times use epoxy that takes 24 hours to cure. Have a fresh razor blade to assist with the tape and wax paper removal.
So it is not a perfect glossy finish repair, but, it is a stronger than new leak free repair and gets you back in the water in one day.
Of course there are dozens of ways to make these types of repairs. This just what worked for me. Hope some one finds this useful.