32-Foot Cabin Cruiser "Sunfish". Part IV.
The molds have to be removed to get in this keelson and the other long fore-and-aft stringers, but as you knock them out after unscrewing the fastenings into the battens put up temporary braces to the ceiling to replace those that held the molds, and nail cross braces to hold the frame apart to its proper width at each mold space.
Measure carefully just where the top edge of the 6 x 1 1/2-inch yellow pine clamp is to come, which is the thickness of the deck 7/8-inch and the depth of the frame 1-inch below the deck edge; 2 3/8 inches in all. This clamp is the binder that holds the top ends of all the frames true into line. Although it is 6 inches deep in the middle, it should be tapered to about 4 inches in depth at the ends, and if you have a power planer handy, its thickness might be reduced to 1 1/4 or 1 1/8 inch at the ends to help it bend, for it makes a pretty stubborn piece to handle. Steam it well before you try to bend it in place and you can then edge set it up or down, as you will find you have to, due to the tumble-home of the topsides, which point the ends down. It takes two pieces 32 feet long to get out these clamps, or one piece of 4 x 6-inch stuff ripped in two.
There are two bilge clamps on each side of 3 x6-inch yellow pine, and though they may be a foot or so shorter, it would pay to order them all the same length, 32 feet, as the saw-mill would probably have to rip them all out of one big piece of yellow pine to get the length.
Use 3/8-inch galvanized carriage bolts to pull the clamp and bilge stringers snug to the frames at every other frame and then, when you bend the shelf in against the clamp, put a through bolt at every other frame clean through the whole lot, frame, clamp and shelf. This will give a stiff, rigid deck edge that will resist any bangs she may get alongside a dock.
Cut the forward ends of these clamps and stringers so that they butt flat up against the stern and transom.
Frame the deck before you start in to plank her up and it will be easier to work. The deck beams are all cut rounding with a "crown" or curve of 5 inches in 7 feet. Saw the deck beams out. Don't bend them. Bent ones have a way of flattening down again and there are not very many of them. Cut a wide thin board so that it forms a "she" pattern of this curve, and by trying this pattern at intervals along her deck you can make sure of getting all the short beams along the cabin space set true to the curve.
Interior of 32-Foot Cabin Cruiser "Sunfish"
Go carefully over the frames with a batten before you start to plank and see that all the frames are true. Shave off a little here and there wherever a frame presents a hard edge, and when you are sure the frame is all true, start and plank her up.
It will take about 500 square feet of 3/4-inch cedar boards to do this. Buy "dressed" — as planed-up lumber is called — and insist on good, clear lumber. You can't expect to get cedar without knots, but shun all sap, which is the bluish cast found near the edges inside the bark. Knots are solid but the sap turns to a soft punk that is apt to produce leaks. All small knots that show a black ring around them should be reamed out after the boat is planked and wooden plugs dipped in shellac driven in and sawed off flush.
There is no royal road to planking up a boat. I have had many people ask me if they can't make one pattern, and get a mill to saw them all out for them, that will plank up the whole boat. You cannot do this. Every plank requires a different shape, though the one pattern will, of course, do for both sides.
Take a "spilling," as boat builders call it, for the top strake. For this you want some very thin planks — about six in all — 14 to 16 feet long, say 6 to 8 inches wide, and about 3/8-inch thick. Tack this spilling board lightly to the frame as nearly as it will go without being forced sideways and into the place where the topstrake is to fit. If it touches the sheer line at about mold number three it will be several inches too low at the ends. This board will give you the curve as far as amidships, aft tack another one the same way, and where the two lap amidships tack them together. Then, get a pair of carpenter's dividers. Set them to span the greatest space between the sheer line and this spilling board — screw the dividers so as to hold their legs apart — and front the sheer line at about every other frame prick off on this spilling board this distance; then by carefully removing these boards and laying them out flat on the plank, you are going to cut the top strake out, if you can prick this distance back onto it and get the curve to cut the top edge so that when bent around the frames it will fit true along the sheer line. The lower edge of this plank is then marked out by bending a long thin batten so that it makes a fair curve, leaving the plank about 4 inches wide amidships and tapered to about 2 1/2 inches forward and 2 inches aft.
In putting this top strake on, have two braces. In one have a bitt to bore for the wooden plug, about a 3/8-inch auger bitt if your 2 1/2-inch copper wire nail heads will go into that sized hole without tearing the wood; if not use a 7/16 inch, or even a 1/2-inch bitt. In, the other brace I have a gimlet bitt — a breast drill with a small bitt works faster and easier and is more generally used by boat builders — some shops having an electric drill that goes through the wood as if it were cheese, and is a great time-saver. Follow through with this smaller bitt, boring a hole into which the copper nail squeezes tightly.
Have the plank squeezed up good and hard to the frames with screw clamps, putting a chip under the foot of it so that it will not bruise the surface of the plank and rivet the plank on. Where the clamps will not permit riveting use flat-head brass screws 1 3/4 or 2 inch, No. 10. Scrape a little coarse brown washing soap onto the threads and the screws will turn in easier. Or if you can't afford screws use galvanized iron boat nails.
Use your spilling board again to find the shape of the top edge of the next two boards and in this way put on about three strakes of top planking. As the top plank is a sort of binder, many prefer to make that board of quartered oak or of yellow pine. Yellow pine is good and you easily can get that kind of wood in lengths-long enough to make it all in one piece.
Then spile in the same manner for the shape of the garboard where it fits along the keel. Cut your thin spilling boards so that they fit roughly to the shape at the ends and get out the garboards. They, too, should be of oak or yellow pine, but instead of being wider in the middle than at the ends, they are just the reverse. The idea is to fill up the surface with the top strakes and the garboards so that the remaining space to plank up will be more like a barrel and take boards more of an even shape and size. If you cannot do this with the garboard alone, put one or two more strakes above it, the first and second broad strakes as they are called, making them about 6 inches wide and tapered so that the rest of the space can be divided equally both at middle and ends.
Section mold of 32-Foot Cabin Cruiser "Sunfish"
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