Thursday, June 29, 2006

Reunification

The kayak is now "one".

The inside seams have been fiberglassed using the method described on the Outer Island Kayak web site. The basic process is to cut strips of fiberglass cloth (I made my strips 2 - 2.5" wide, 6 ounce cloth) and use small dabs of hot glue to tack the cloth in place along the shear line of the hull so that the cloth will end up evenly spanning the seam. The deck was then carefully laid over the hull and the ends taped into position. The hull had pulled inwards so the hull and deck did not mate perfectly and I needed to even things up. I found that trying to use tape and straps to bring the hull and deck flush was not that effective, partly because this method can only push the deck inward and does not allow the hull to spread to meet halfway. Also, since the hull overlapped the deck, the pressure from tape and straps pushed the edges past each other rather than causing them to meet. Instead, I used a method I had seen described on the KBBB where u-shaped pieces of wood are tacked to the hull with hot glue near the top edge, then a wedge is driven in past the deck which causes equal pressure pulling the hull outwards and pushing the deck inwards. I found this worked very well and it was easy to convert a bunch of plywood scraps (former strip-holding jigs from when I thought I would build this boat "staple-less") into u's and wedges. I placed a bunch of these jigs along the seam on each side, wherever things needed to be pushed into alignment and used fiber-reinforced strapping tape to tape the halves together. I then attempted to use clear packing tape (too thin, too cheap) to seal the seam but could only manage to do this between the jigs.

With everything aligned and taped up, I turned the boat on it's side and hoisted one end up with a strap from the ceiling such that epoxy poured onto the seam through the hatch opening would run downhill and into the end. I attached a sawed-off brush at a 45 degree angle to the end of a stick and used this to reach in through the hatch openings and push the pool of epoxy where it needed to go to wet out the cloth, ensuring it reached the extremities. With one end epoxied in this way, I raised the other end and did the rest of the seam, then returned the boat to level (still on side). I added a second layer of glass (3" wide, 4 ounce cloth) in the cockpit area for extra strength.

Once this mess had cured for about 24 hours, I knocked the alignment jigs off with a mallet then scraped/cut/sanded away the excess hot glue and all the epoxy that came through. Because my packing tape was crappy, I had trouble getting it off. Because the jigs were in place before I put on the tape, it did little to prevent epoxy from coming through the joint and caused it to pool in many places. As a result, most of my jigs were epoxied in place, though since the epoxy was still only partly cured, they came off without too much trouble.

With the starboard side taped, I then turned the boat over and repeated the process for the other side.

Some comments I have at this juncture:
  • Sheer clamps as used on some kayak designs look like a pretty good idea right now. Sheer clamps are strips of wood which extend the length of the boat along the sheer line, providing a surface to which the deck can be attached. Sheer clamps are common on boats which have a fairly flat deck where the deck and hull meet at a sharp angle (not the case in a guillemot).
  • Purchased 2" wide fiberglass tape with selvaged edges may produce a neater job than my version of cutting my own strips from regular width cloth on the bias since this would avoid all the loose strands and frayed edges.
  • I'm not sure how I'll clean up the rough/sharp surface of the inside seam. I guess I'll have to shape a sanding block of some sort and attach it to a pole. It'll have to be narrow enough to fit most of the way into the tips. I'm not worried about aesthetics here, but the sharp bits of glass fiber that protrude along the seam will shred whatever I put in the hatches.
  • The current weight is 35 lbs (no seat, bulkheads, etc) according to the bathroom scale.
I had hoped to be finished with the kayak by now. This weekend we are getting possession of our new house and thus, the rest of the work to finish the kayak (outside seam, hatch closures, bulkheads, seat, foot brace, back rest, thigh braces, varnish, padeyes, deck lines) will have to wait until August once we are settled in the new place. In the meantime I have one heckuva mess to clean up/pack up in the garage.

See you in August!