I am currently in the early stages of building a Lapwing, a 4.77m glued lapstrake cat ketch design from B&B Yacht Designs. My last boat was a Core Sound 17, another cat ketch from B&B, which I sold a year ago. I’ve not built a glued lapstrake boat before, so I’m picking up a new set of skills and enjoying myself immensely.
This glued-lapstrake design uses a number of bulkheads that are part of the boat, instead of a strongback, plus a couple of temporary frames, all propped up on a pair of home made saw horses. In building this boat I’m remembering the joy of using well-sharpened planes and chisels, and the effectiveness of a nicely curved filleting stick!
How long will it take to build? No idea, but I’m not in a race, and I’ve come to the conclusion that messing about WITH boats is as much fun as messing about IN boats. I’ve been watching an excellent series on building a Caledonia Yawl, on the offcenterharbor.com website, and a lot of the ideas I’ve found there will be regularly applied during my new build.
I started off by building a couple of saw horses to the appropriate height for this boat. A drop saw made accurate and fast work of the cuts needed when assembling these.
These are used to support the longitudinal bulkheads that the fore and aft bulkheads slot into, along with a couple of temporary MDF bulkheads that help to keep the planks following the correct shape.
When building this boat you don’t use a conventional frame, rather, the bulkheads are used in place of a frame, and planks are glued to them as the build progresses. Some parts of the permanent bulkheads are cut away when the boat is turned over, and upon reflection I wonder whether it would have been simpler to make these cuts before starting, and then joining the pieces back together again with temporary battens.
Once they were out of the way, I started making clamps, lots of clamps, using the design I found on the Duckworks Magazine site, at https://www.duckworksmagazine.com/07/howt o/clamps/index.htm. Although this photo doesn’t show it, when in use I covered the blocks in tape, to prevent them from being glued to the planks.
I also made a few Brenne clamps (https://smallboatsmonthly.com/article/a-levercam- planking-clamp/), with over-centre cams, which could be operated with one hand, but as it turned out, the bulkheads for the boat, when combined with the judicious placement of some F clamps to rest the plank against meant that the lapstrake clamps were all that I really needed.
Next, I had to transfer the shapes of the components for the stem from the rolls of mylar plans onto some of my timber. I used a gimlet that had belonged to my Grandfather to prick holes through the mylar and into the wood. These holes were then joined up with a steel ruler and pencil, cut out oversize with a bandsaw, and then planed down to the correct dimensions.
Whilst building the stem, I was reminded of the benefit of using a soldering iron to heat up a screw, to break the grip of the epoxy locking it in place. A minute or so of holding the soldering iron on the end of the screw made it easy to remove stubborn screws once the glue had set!
Once the stem had been set aside, I tackled the scarfing joints used to make the double-length sheets I would need for cutting out the planks. I laid out the eight sheets needed, offsetting each sheet by 50mm from the sheet below, clamped everything in place, and used a No. 6 plane to remove the excess plywood. The glue lines between each lamination in the plywood gave be a simple way of seeing how close I was to the required smooth diagonal surface.
When I was happy with the finished surface, it was just a matter of joining two sheets, coating the diagonally planed surfaces with unthickened epoxy, and then gluing the surfaces together with thickened epoxy, clamping and weighting the panels, and letting the glue dry. These long panels were then set aside for later use. The next step was to use the gimlet again, to mark out the shapes of the transom and bulkheads on some of the remaining sheets of ply, and then cutting these out oversize, using a jigsaw and then planning them down to the right size.
After the transom was bent and glued to shape, it and the bulkheads were then slotted into one another, and placed on the sawhorses. After measuring and tweaking to make sure that everything was level and true, keel batten and the bulkheads that were to remain in the boat were glued and taped together.