Sunday, July 15, 2007

Wooden kayak morphing into fiberglass

The wires (aka boat clecoes) are all removed, and the wooden shell of the kayak is just strong enough from the tack glue joints to hold its form against gravity and the periodic bumps it gets from my clumsy walking around. It's weak as a kitten and would leak like a NY Times front page if it got anywhere near the water, but the next few steps will start to correct that.

First, the inside of the hull will be strengthened and waterproofed. The fore and aft compartments will have 3" fiberglass tape applied to all of the wood joints, and a coat of clear epoxy applied to the bare wood surfaces not covered by the tape. The cockpit area is a little different: a large sheet of fiberglass cloth will coat the entire inner surface.

Both forms of fiberglass share a common weakness: they will not adhere well to sharp angles. In the cockpit, that isn't a very big problem but in the fore and aft sections, there are very sharp angles where the panels meet. The cure for this is to mix up a batch of what the manual calls 'peanut butter,' which is simply epoxy filled with sawdust until it attains a moldable consistency:

This peanut butter (and just so you know, the manual has already called for 'ketchup' and 'mustard' - I'm still waiting for 'maple syrup' and 'spaghetti sauce') gets spread down into the crevices formed by the joined panels and shaped to a nice, round fillet. I used a ZipLoc bag with the tip of one of the corners cut off:

I invented a tool to make the fillet shape up in the tight confines of the sharp ends of the boat by sanding the sides off of a plastic spoon:

Patent Pending

Once the peanut butter is in place, the tape is laid onto it, and clear epoxy is brushed over the whole enchilada:

Both the fore and aft are done - I just followed up the tape, peanut butter, and clear epoxy with a second coat of epoxy this evening. Tomorrow I will so the cloth and epoxy in the cockpit section.

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