Tuesday, April 29, 2008

Hull glass prep

No video for this post, as the task at hand consisted mostly of sanding. And the only thing more dreary than sanding is watching a couple of minute of video of someone sanding. Anyway, with stitches removed, the hull now can be prepped for application of a layer of fiberglass. Before that step, however, the hull must be smooth with no sharp edges. Fiberglass has a limited capacity to bend around sharp corners, so the chines must include a radius, and all the other dings, snags and seams of the hull must be smoothed. I had to use a chisel to lop off a few protruding copper wire stitches that weren't flush. That worked fairly well, except for a few additional gouges I put in the wood with the chisel. Then came out the "Darth Sander" costume, and sanding began. The chines also were rounded off with the trusty Black and Decker quarter sheet orbital sander and some 100-grit sandpaper. After careful work, the result is a nicely smooth and well-radiused multi-chine hull. Before glassing, though, gaps in the chine seams and stitch holes will have to be filled with thickened epoxy, and the hull sanded again. But that's the topic for next post! Total hours 19.50.

Monday, April 28, 2008

Stitch removal

video

The hull could now be flipped over, and the copper wire stitches removed. The approximately 250 stitches that had been painstakingly drilled and twisted have now served their purpose, and were clipped off flush with the hull exterior. The portion of the stitch embedded in the epoxy fillet will remain, but the exterior portion was clipped off. I found it easiest to untwist the tighter stitches a few turns, in order to provide room to slip the small wire cutter under the loop. A word to the safe: wear eye protection! Some of the wire fragments can fly in dangerous directions. With the stitches removed, the hull is now ready for sanding and filling prior to fiberglassing. Total hours 18.50.

Sunday, April 27, 2008

Carlins

video

With the deckbeam in place, I next installed the carlins. These are small, flexible pieces of lumber that will form the framework that supports the inner edge of the deck, along the periphery of the cockpit. In contrast to some reports of other builders, I had no problem bending the carlins along the fair curve described by the hanging knees and deck beam. Chalk it up to the humidity of spring in the deep south, I suppose. After a bit of trimming and bevelling at the bow end of the carlins, I tested for a tight fit in the notch formed by the blocks on the deck beam. Once everything was ready, I mixed a small amount of mustard epoxy and coated the mating surfaces, the returned the carlins to position and clamped in place. At the bow, I clamped a piece of scrap to wedge the two carlin ends snugly against the deck beam notch. Total hours 17.50.

Saturday, April 26, 2008

Deckbeam


video

Installation of some structure to support the deck came next. The position of the deckbeam was measured relative to the forward bulkhead. The pair of arched, precut plywood pieces had been previously epoxied together, forming a strong beam unit. Holding the piece in place, the ends were marked and cut, then bevelled and planed until they fit snugly in place between the sheer clamp in the correct position. Pilot holes were drilled and countersunk for #8, 1-1/2" bronze screws to hold the beam in place. Next, the centerline was measured by dividing the beam by two. This matched well with the centerline position given by a string stretched from bow to stern on the hull. From the plans, the position of the wood blocks were marked on the deck beam, and these were also drilled and screwed into place. Once everything fit satisfactorily, it was all disassembled. Some mustard epoxy was mixed with silica, and the parts were coated at the joint faces. The beam and then the blocks were screwed back into place. I had intended to install the carlins as well, but decided to let the deck beam parts cure before that. Besides, I only have two bar clamps, and will need two more to do the carlins... Total hours 17.00.