Small Craft Home : Boats : Nutshell Pram
The Nutshell Pram
Here we build Joel White's Nutshell Pram so the squeaker has her own boat to learn with. As we progress with the construction over the summer I'll post details here.
We are building the pram from plans vs. a kit. Both are available from The WoodenBoat Store.
Here is the building jig all set up. Nothing particularly challenging here - some 2 x 4's with cross pieces of 1 x 2 and 1 x 4. The only thing that had me scratching my head for a moment were the two upright stern transom supports. They stand at an angle of 79 degrees which had me pulling my drafting compass out to get things properly situated. It actually took longer to find the compass than it did to cut out and set up the uprights!
With the basic jig in place it is time to get the two disposable molds out. These are cut from 1/2" plywood. No bevel is put on their edges, they are aligned on the jib so that the fore or aft edge (fore or aft mold, respectively) lines up with the proper mark on the jig and will be the contact point for the planking. Note the nailing stretcher attached to each mold and spanning the width of each one - adding stiffness and an easy means of screwing down the mold to the jig. Each mold is braced with an angled 1x2 run down to one of the jig cross-pieces.
The next step is to get out the bow and stern transoms. These require a bit of "measure twice, cut once" thinking to ensure that one leaves enough material for the bevels called for in the plans. I started cutting the bevels on the table saw but decided it was much faster and easier (though a tad less precise) to use the Skilsaw and eyeball it. Once shaped, and with the removable cleat designed to align each transom with the building jig, the stern transom goes right on to those angled uprights. In the process the uprights can be cut down to proper length (height?) since I started with more material than I'd end up needing.
At this point in construction the bow transom isn't yet mounted. First I must laminate the fore-knee that'll support this transom. I'm using a piece from an old futon frame for the wood - it seems to be very strong (I've been using 'em for years for various building jigs) and it is certainly light-weight. So I cut it up into 1/8" thick strips on the table saw and then glue them back together across the jig made up from scrap lumber from a previous boat project. You can never have enough clamps!
Okay, now the transom is glued to the transom knee and the whole attached to the building jig - with the knee fitting right into the notch cut in the forward mold. Almost ready for planking. One final thing is the mid-ship frame which I laminate just like the transom knee. In this instance I'm using a Douglas Fir 2 x 4 cut into 1/8" strips on the table saw. A stack of these will bend around my jig just fine. The jig itself is made from an old station mold from a previous boat-building project that was sitting around waiting for some purpose (and now we know what!).
Here's the finished mid-ship frame in place on the building jib. It's been planed down to the correct thickness, sanded, inboard edges rounded over and limber holes bored using a 1" Forstner bit set halfway in for a nice shape. Getting the bottom out of a 3/8" piece of plywood was the work of an hour or so and here it is having already been dry-fitted once (with the final screw holes bored and counter-sunk) - ready for final fitting.
Here's the bottom permanently attached (glued and screwed) with the bevels for the garboards cut. also note the wax paper taped (or stapled) into place to prevent any epoxy from binding the hull to the molds.
