The Boy Mechanic Part 56

** How to Make a Sailing Canoe [199]

A canvas canoe is easily made and light to handle, but in making one, it must be remembered that the cloth will tear, if any snags are encountered. Therefore such a craft cannot be used in all waters, but by being careful at sh.o.r.es, it can be used as safely as an ordinary sailing canoe. Be sure to select the best materials and when complete cover the seams well with paint.

[Ill.u.s.tration: Completed Sailing Canoe]

The materials necessary for the construction of a sailing canoe, as ill.u.s.trated in the engraving, are as follows:

1 keelson, 1 in. by 8 in. by 15 ft., selected pine.

14 rib bands, 1 in. square by 16 ft., clear pine.

2 gunwales, 1 in. by 2 in. by 16 ft.

1 piece for forms and bow pieces, 1 in. by 12 in. by 10 ft.

4 outwales, 1/4 in. by 2 in. by 16 ft.

1 piece, 3 in. wide and 12 ft. long, for c.o.c.kpit frame.

1 piece, 2 in. wide and 12 ft. long, for center deck braces.

11 yd. of 1-1/2-yd. wide 12-oz. ducking.

8 yd. of 1-yd. wide unbleached muslin.

50 ft. of rope.

1 mast, 9 ft. long.

Paint, screws and cleats.

The keelson, Fig. 1, is 14 ft. long, 8 in. wide in the center and tapered down from a point 4 ft. from each end to 1 in. at the ends. Both ends are mortised, one 6 in. for the stern piece, and the other 12 in. for the bow. Be sure to get the bow and stern pieces directly in the middle of the keelson and at right angles with the top edge. The stern and bow pieces are cut as shown in Fig. 2 and braced with an iron band, 1/8 in. thick and 3/4 in.

wide, drilled and fastened with screws.

Study the sketches showing the details well before starting to cut out the pieces. Then there will be no trouble experienced later in putting the parts together. See that all the pieces fit their places as the work proceeds and apply the canvas with care.

Two forms are made as shown in Figs. 3 and 4; the smaller is placed 3 ft. from the bow and the large one, 7 ft. 3 in. from the stern. The larger mould is used temporarily while making the boat, and is removed after the ribs are in place. The gunwales are now placed over the forms and in the notches shown, and fastened with screws, and, after cutting the ends to fit the bow and stern pieces, they are fastened with bolts put through the three pieces.

The sharp edges on one side of each rib-band are removed and seven of them fastened with screws to each side of the moulds, s.p.a.cing them on the large mould 4 in. apart. The ribs are made of 28 good barrel hoops

[Ill.u.s.tration: Details of a Home-Made Sailing Canoe]

which should be well soaked in water for several hours before bending them in shape. These are put in 6 in. apart and are fastened to the rib-bands with 7/8-in. wood screws. The ribs should be put in straight and true to keep them from pulling the rib-bands out of shape. After the ribs are in place and fastened to the rib-bands, gunwales and keelson, put on the outwale strips and fasten them to the gunwales between every rib with 1-1/2-in.

screws.

Before making the deck, a block for the mast to rest in must be made and fastened to the keelson. This block, Fig. 5, is a cube having sides 6 in. square and is kept from splitting by an iron band tightly fitted around the outside. The block is fastened to the keelson, 3-1/2 ft. from the bow, with bolts through countersunk holes from the under side.

There are three deck braces made as shown in Figs. 6, 7 and 8.

Braces, Figs. 6 and 7, form the ends of the c.o.c.kpit which is 20 in. wide. A 6-in. board is fitted into the mortises shown in these pieces; a center piece is fitted in the other mortises. The other deck braces slope down from the center piece and are placed 6 in.

apart. They are 1 in. square and are mortised into the center piece and fastened to the gunwales with screws. The main deck braces are fastened to the gunwales with 4-in. corner braces and to the center piece with 2-in. corner braces. The mast hole on the deck is made as follows: Secure a piece of pine 1 in. thick, 6 in.

wide and 3 ft. long. Cut this in halves and mortise for the center piece in the two halves and fasten to the gunwales. A block of pine, 4 in. thick and 12 in. long, is cut to fit under the top boards, Fig. 9, and fastened to them with bolts. With an expansive bit bore a hole 3 in. in diameter through the block. Be sure to get the block and hole directly over the block that is fastened to the keelson. Put on a coat of boiled linseed oil all over the frame before proceeding farther.

Putting on the canvas may be a difficult piece of work to do, yet if the following simple directions are followed out no trouble will be encountered. The 11-yd. length of canvas is cut in the center, doubled, and a seam made joining the two pieces together.

Fill the seam with thick paint and tack it down with copper tacks along the center of the keelson. When this is well tacked commence stretching and pulling the canvas in the middle of the gunwales so as to make it as even and tight as possible and work toward each end, tacking the canvas as it is stretched to the outside of the gunwale. Seam the canvas along the stern and bow pieces as was done on the keelson. The deck is not so hard to do, but be careful to get the canvas tight and even. A seam should be made along the center piece. The tr.i.m.m.i.n.g is wood, 1/4 in. thick and 1/2 in.

wide. A strip of this is nailed along the center piece over the canvas. The outwales are nailed on over the canvas. A piece of oak, 1 in. thick 1-1/2 in. wide and 14 in. long, is fastened with screws over the canvas on the stern piece; also, a piece 1/4 in.

thick, 1 in. wide and 24 in. long is well soaked in water, bent to the right shape and fastened over the canvas on the bow.

The rudder is made as shown in Fig. 10 with a movable handle. A strip 1 in. thick by 2 in. wide, is bolted to the keelson over the canvas for the outer keel. The keel, Fig. 11, is 6 in. wide at one end and 12 in. at the other, which is fastened to the outer keel with bolts having thumb nuts. The mast can be made of a young spruce tree having a diameter of 3 in. at the base with sufficient height to make it 9 ft. long. The canoe is driven by a lanteen sail and two curtain poles, each 1 in. in diameter and 10 ft.

long, are used for the boom and gaff, which are held together with two pieces of iron bent as shown in Fig. 12. The sail is a triangle, 9-3/4 by 9-3/4 by 8-1/2 ft. which is held to the boom and gaff by cord lacings run through eyelets inserted in the muslin. The eyelets are of bra.s.s placed 4 in. apart in the muslin.

The mast has two side and one front stay, each fitted with a turnbuckle for tightening. A pulley is placed at the top and bottom of the mast for the lift rope. The sail is held to the mast by an iron ring and the lift rope at the top of the mast. The boom rope is held in the hand and several cleats should be placed in the c.o.c.kpit for convenience. A chock is placed at the bow for tying up to piers. Several coats of good paint complete the boat.

--Contributed by O. E. Tronnes, Wilmette, Ill.

** A Home-Made Hand Vise [201]

A very useful little hand vise can easily be made from a hinge and a bolt carrying a wing nut. Get a fast

[Ill.u.s.tration: Hand Vise Made from a Hinge]

joint hinge about 2 in. or more long and a bolt about 1/2 in. long that will fit the holes in the hinge. Put the bolt through the middle hole of the hinge and replace the nut as shown in the drawing. With this device any small object may be firmly held by simply placing it between the sides of the hinge and tightening the nut.

** Proper Design for a Bird House [201]

This bird house was designed and built to make a home for the American martin. The house will accommodate 20 families. All the holes are arranged so they will not be open to the cold winds from the north which often kill the birds which come in the early spring. Around each opening is an extra ring of wood to make a longer pa.s.sage which a.s.sists the martin inside in fighting off the English

[Ill.u.s.tration: Bird House]

sparrow who tries to drive him out. The holes are made oval to allow all the little ones to get their heads out for fresh air.

The long overhanging eaves protect the little birds from the hot summer sun. The rooms are made up with part.i.tions on the inside so each opening will have a room. The inside of the rooms should be stained black.

** Boomerangs and How to Make Them [202]

A boomerang is a weapon invented and used by the native Australians, who seemed to have the least intelligence of any race of mankind. The

[Ill.u.s.tration: Details of Three Boomerangs]

boomerang is a curved stick of hardwood, Fig. 1, about 5/16 in.

thick, 2-1/2 in. wide and 2 ft. long, flat on one side, with the ends and the other side rounding. One end of the stick is grasped in one hand with the convex edge forward and the flat side up and thrown upward. After going some distance and ascending slowly to a great height in the air with a quick rotary motion, it suddenly returns in an elliptical orbit to a spot near the starting point.

If thrown down on the ground the boomerang rebounds in a straight line, pursuing a ricochet motion until the object is struck at which it was thrown.

Two other types of boomerangs are ill.u.s.trated herewith and they can be made as described. The materials necessary for the T-shaped boomerang are: One piece of hard maple 5/16 in. thick, 2-1/2 in.

wide, and 3 ft. long; five 1/2-in. flat-headed screws. Cut the piece of hard maple into two pieces, one 11-1/2 in. and the other 18 in. long. The corners are cut from these pieces as shown in Fig. 2, taking care to cut exactly the same amount from each corner. Bevel both sides of the pieces, making the edges very thin so they will cut the air better. Find the exact center of the long piece and make a line 1-1/4 in. on each side of the center and fasten the short length between the lines with the screws as shown in Fig. 3. The short piece should be fastened perfectly square and at right angles to the long one.

The materials necessary for the cross-shaped boomerang are one piece hard maple 5/16 in. thick, 2 in. wide and 30 in. long and five 1/2-in. flat headed screws. Cut the maple- into two 14-in.

pieces and plane the edges of these pieces so the ends will be 1-1/2 in. wide, as shown in Fig. 4. Bevel these pieces the same as the ones for the T-shaped boomerang. The two pieces are fastened together as shown in Fig. 5. All of the boomerangs when completed should be given several coats of linseed oil and thoroughly dried.

This will keep the wood from absorbing water and becoming heavy.

The last two boomerangs are thrown in a similar way to the first one, except that one of the pieces is grasped in the hand and the throw given with a quick underhand motion. A little practice is all that is necessary for one to become skillful in throwing them.

--Contributed by O. E. Tronnes, Wilmette, Ill.

** How to Make Water Wings [202]

Purchase a piece of unbleached muslin, 1 yd. square. Take this and fold it over once, forming a double piece 1-1/2 ft. wide and 3 ft.

long. Make a double st.i.tch all around the edge, leaving a small opening at one corner. Insert a piece of tape at this corner to be used for tying around the opening when the bag is blown up. The bag is then turned inside out, soaked with water and blown up. An occasional wetting all over will prevent it from leaking. As these wings are very large they will prevent the swimmer from sinking.