The following images are somewhat out of the actual construction sequence in order to explain each process of the hull shaping.
This design will get a gunnel and not an interior sheer clamp. Because there is a lot of shape to the sheer, the gunnel needs to be laminated. The hull is used as a mold and layers of plywood are laminated to it with a piece of plastic as a barrier to keep the gunnel from sticking to the hull. From the bow to just past the aft bulkhead, two layers of 1/2" plywood are used. I cut two 4" strips for each side from the fall down pieces created when the side panels were cut out. There is some shape to the sheer and the fall down pieces fit without scribing and custom cutting strips to fit.
Dryfit the pieces to make sure they lay out properly. The two mating surfaces are wet out with thickened epoxy and screwed to the hull. After it has cure pull the gunnels and plastic, and grind the outside face smooth. Screw the gunnel back on making sure it is slightly lower than the sheer (As the boat sits). Run a router with a straight flush cut bit along the gunnel to clean the top edge of the gunnel. When the gunnel is pulled off, it can be scribed off the newly cleaned edge and cut to about 3 1/2". The bottom edge of the gunnel is then shaped at 45 degrees.
The stern piece needs to be made out of 4 layers of 1/4" plywood. There is a lot of shape around the stern so a pattern should be made first. It can then be made like the forward pieces were. When gluing it up start in the center and work out. It should also extend about 12" beyond the end of the side pieces.
This design also gets a bulwark forward on the deck so I made those like I did the gunnels. I made them about 14" tall so I have a lot to play with when it comes to cutting and fitting them. The first layer is full length and outer layer was made out of a couple of pieces, I used more of the fall down from the hull panels to make them. Because the plywood is fairly tall there would have been a good bit of spring back when taken off so I scored the first layer through several plys about three feet fore and aft of the first bulkhead where most of the shape is. Both layers were epoxied and screwed to the hull. I used fairly thick epoxy at the scored section so it would not drain out. The first layer is also a couple inches longer than the outer so the ends can screwed to the hull and not covered up by the second layer so the screws can be pulled after it has cured. These pieces can now be stored out of the way.
The gunnel can now be installed. I used a simple lap joint just aft of the aft bulkhead. All mating surfaces were wet out with slightly thickened epoxy and screwed in place. I pulled the screws after it cured.
There are several steps to properly shape the chine. I first used a grinder and hard pad with 36 grit sandpaper to get the side panels ground flush with the bottom panels. When you have a square corner it is easiest to sight down it and find any unfair lines. After I got the chine corner fair I ground through the first ply of the plywood about two inches on each side of the corner. The chine is rounded over with a block plane and a flexible blasterboard after that to get the radius smooth. I added a layer of biax and tooling cloth to the joint for strength and by removing some of the plywood at the edge the biax will fair out easier leaving no edge that will would have to be filled later.
The plans call for a keel but it was omitted to keep the draft shallow. The center joint of the bottom panels gets a layer of biax and tooling cloth. After that a piece 1" x 3" Yellow Cedar is fit, epoxied and screwed in place. A piece of black PVC half oval is dryfit. After the hull is sheathed and sealed The PVC will be installed with Sikaflex and ss screws.
The hull is sheathed with one layer of Dynel. Dynel uses a lot of epoxy to wet out so I rolled epoxy on the hull, draped the Dynel over the hull and rolled on more epoxy. On this hull I sheathed from shear to shear by laying the Dynel tight over the hull. I wet out the bottom and ran a razor blade down the center of the keel shoe which made it easy to get the Dynel to lay down on the fillet on each side of the shoe. The bottom corner of the stern gets cut out so I didn't need to cover it.
The stern of the hull had some unfairness so I filled the low areas with an epoxy/microballoon filler. After it cured I faired it out, sanded the rest of the hull and sealed the entire hull with three coats of epoxy.
This is a Devlin design, for more information on this design and others offered by Devlin Boat, go to devlinboat.com
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