23-Foot Cabin Cruiser "Beaver". Part VI.
Be sure to brace the frames the same as you did the molds, before you remove them to put in frames in their place, because the boat will be subjected to considerable strain in being planked. For this same reason it is better to put in all the deck beams, cabin beams, and even the cockpit floor beams can be fitted, but not fastened, as the latter would be in your way when riveting up the plank fastenings. This work can be done so much easier now than after the hull is all shut in with planking. The cabin beams are of oak, I inch thick by 1 1/2 to 2 inches deep, cut with a sweep that raises them 9 inches in the width of 9 feet. You can either sweep this curve with a long wire or a batten about 13 feet 3 inches long, or you can lay it out by taking the measurements off a smaller circle swept with a 9-inch radius. The quarter of the circle is divided into four parts, a, b, c, and the base line in four, d, e, f. Then, on a thin (1/2-inch) pine board 9 feet long, snap a chalk line for a base line, and in the middle measure up 9 inches, then from the middle toward each end divide the 4 1/2 feet into four equal parts, d, e, f, and lay off the distances a, b, c, etc., on the bevels, as found in the small circle. Do the same reversed for the other side and then, by bending a batten through these spots, you get a true curve for a pattern or beam mold by which to mark out your cabin deck beams.
The beams across the after deck can be cut from the same pattern, but those across the cockpit floor should be laid out to a very much flatter curve, one with only about 2 inches round in the width of the cockpit. Many amateurs, I know, will make them straight across, because it is easier to do so. The advantages of having them curved a little is that they will drain off any rain water quicker than one laid dead flat.
Now comes the job of planking up. This frightens many amateurs, but, as a fact, it is one of the most interesting parts of all, when done right and studied as you go on with it. Like an economical tailor, you can cut your planking so as to make it go a long ways or, if you don't use your head and good judgment in selecting the boards, you can waste a lot of cedar. There is, at best, considerable waste in planking a boat, about 25 per cent., generally, varying more or less as the shape of the boat approaches or departs from a round, barrel-like shape.
The principle of planking a boat is the same as the construction of a barrel. The barrel staves are all shaped wider in the middle and narrower at the ends, only in a boat the ends are not all the same size as in a barrel. After one or two planks have been fitted onto our hull, we will return to this barrel principle and you will realize the similarity in construction.
The first, and perhaps the hardest, plank of all to fit is the one next to the keel, called the garboard strake. The difficulty is principally in not knowing how, and in trying short cuts, but I can assure you that the ancient boat-builders have in the past centuries found and made use of all short cuts, and so don't you try to find out any more..
I know I did when I built my first boat, but I had to come back to the orthodox method of "spilling." Spilling for the shape of a plank consists of tacking a thin board, say, 3/8-inch thick, to the frames, so that its lower edge, in near the rabbet, along on the keel, is cut so that it roughly fits to the curve the rahbet takes onto the stem, as shown in Figure 9; with another such board tacked to the after end and the two lapped and nailed together amidships, or one long plank, if you have it. With a pair of dividers set to span the greatest distance between this "spilling staff," as it is called, and the rabbet, prick off a series of spots to give you the curve necessary to cut the garboard to, so it will fit. At the ends, where there is considerable curve, lay your rule across at intervals of 3 or 4 inches, and mark a series of lines, to give you the direction in which the measurements are to be taken off and measured back on. Take plenty of measurements around these curves, but along amidships, where the rabbet runs in a straight line, you will not need so many. One every foot or 18 inches will be enough.
Interior of 23-Foot Cabin Cruiser "Beaver".
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