This form of hull is simple to make, in that the curves of the outside are all convex. There are no concave surfaces and reversed curves. The surface can be finally shaped by the use of the rasp, followed by a file, and finally smoothed with scraper or glass (see Scraper). Do not use sandpaper until the hull is finished.
The inside must next be hollowed. Gauge a line around the upper side, ½" from the edge, except at the bow and stern, where a greater distance should be allowed (Fig. 356). The hull must now be held firmly in some way. If you cannot contrive to clamp it firmly without bruising the outside, you should arrange some blocks (padding them with cloth or leather) in such a way that it can be held securely. It is better to spend an hour in fastening the block firmly than to attempt to steady it with one hand and to cut with the other. In all the shaping of the boat, both hands should be free if possible. Grasp the blade of the tool with the left hand, or lay the hand across it, so as to exert a back-pressure on the tool. This gives great control of the tool (see Paring).
Fig. 357.
Bore one or more holes (according to the size of the boat) downward from the top (Fig. 356), being very careful not to bore too deeply, but to leave at least half an inch of wood below the hole (see Boring). Now run a groove with the gouge around the deck, inside of the line marked, and hollow out the inside with the gouge, cutting towards the middle. The holes bored will help in this process. Cut down straight from the line marked on the upper side until the thickness of the sides of the hull is reduced to perhaps ¼ of an inch (Fig. 357). The object of the increased thickness at the gunwale is to stiffen the sides and give a better bearing for nailing down the deck. Below this point make the thickness as uniform as you can, except for a narrow space at the very bottom where the keel is to be fastened, where it is often well to leave a thicker ridge (Fig. 357).
Fig. 358.
Extreme care is required in hollowing the inside. It is best not to attempt to make the sides thinner than one fourth of an inch, unless you are a pretty good workman with a fair degree of patience, for it is hard to repair the damage if you cut too deeply. Templates can be made for the inside. You can tell quite well whether you are making the thickness uniform by the sense of feeling, gauging the thickness between the thumb and finger. Do not try to cut away too much at the bow and stern, as it will weaken the boat, but leave a sufficient body of solid wood. Smooth the inside neatly with a flatter gouge (if you have it) than that with which you removed the bulk of the wood.
Next, with a thin strip or batten, mark the line for the sheer of the deck by the saw-kerfs already made and remove the wood carefully to this sheer line. The outside can now be thoroughly sandpapered, first with, perhaps, No. 1½, and finally with No. 00. Get the surface as smooth as possible (see Sandpaper). Next paint the outside and inside with two coats of white lead and oil (see Painting). It is a good plan to apply a coat of hot oil first.
