The Boy Mechanic Part 90

1 Top. 3/16. by 14 by 17 in. 1 Bottom. 3/16 by 14 by 17 in. 2 Sides. 3/16 by 3-5/8 by 16-3/4 in. 1, End. 3/16 by 3-5/8 by 13-1/8 in. 1 End. 3/16 by 3-5/8 by 9-5/6 in. 1 Neck. 1 by 2-5/16 by 18-1/2 in. 1 Fingerboard 5/16 by 2-5/8 by 16 in.

Cut the fingerboard tapering and fasten pieces cut from hatpins with small wire staples for frets. All dimensions for cutting and setting are shown in the sketch. The neck is cut tapering from G to F and from J to F, with the back side rounding. A drawknife is the proper tool for shaping the neck. Cut a piece of hard wood, 1/4 in. square and 1-7/8 in. long, and glue it to the neck at F.

Glue the fingerboard to the neck and hold it secure with clamps while the glue sets.

The brace at D is 1 in. thick, cut to any shape desired. The sides are glued together and then the front is glued on them. Place some heavy weights on top and give the glue time to dry. Fasten pieces of soft wood in the corners for braces. Glue the neck to the box, making it secure by the addition of a carriage bolt at A. A small block C is glued to the end to reinforce it for the bolt. Glue strips of soft wood, as shown by K, across the front and back to strengthen them. The back is then glued on and the outside smoothed with sandpaper.

Make the bottom bridge by using an old hatpin or wire of the same size for E secured with pin staples. Glue the bridge on the top at a place that will make the distance from the bridge F to the bottom bridge E just 24 in. This dimension and those for the frets should be made accurately. Six holes, 3/16 in. in diameter, are drilled in the bottom bridge for pins. The turning plugs B and strings can be purchased at any music store.

--Contributed by J. H. Stoddard, Carbondale,Pa.

** Greasing the Front Wheels of an Automobile [320]

The front wheel bearings of an automobile can be greased without removing the wheels in the following manner: Remove the hub caps and fill them with heavy grease and then screw them in place.

Continue this operation until the grease is forced between all the bearings and out through the small clearance on the opposite side of the wheels. This should be done at least once every month to keep bearings well lubricated and free from grit. Dirt cannot enter a well filled bearing as easily as muddy water can enter a dry bearing.

--Contributed by Chas. E. Frary, Norwalk, O.

** Removing Mold [320]

Mold on wallpaper can be removed at once by applying a solution of 1 part salicylic acid in 4 parts of 95% alcohol.

** HOW TO MAKE A PAPER BOAT [321]

A Light Boat That Can Be Easily Carried

[Ill.u.s.tration: The Paper Boat Is Light and Easy to Propel]

Now you might think it absurd to advise making a paper boat, but it is not, and you will find it in some respects and for some purposes better than the wooden boat. When it is completed you will have a canoe, probably equal to the Indian's bark canoe. Not only will it serve as an ideal fis.h.i.+ng boat, but when you want to combine hunting and fis.h.i.+ng you can put your boat on your shoulders and carry it from place to place wherever you want to go and at the same time carry your gun in your hand. The material used in its construction is inexpensive and can be purchased for a few dollars.

Make a frame (Fig. 1) on which to stretch the paper. A board 1 in.

thick and about 1 ft. wide and 11-1/2 ft. long is used for a keel, or backbone, and is cut tapering for about a third of its length, toward each end, and beveled

[Ill.u.s.tration: Detail of Framework Construction]

on the outer edges (A, Fig. 2). The cross-boards (B, B, Fig. 2) are next sawed from a pine board 1 in. thick. Shape these as shown by A, Fig. 4, 13 in. wide by 26 in. long, and cut away in the center to avoid useless weight. Fasten them cross-wise to the bottom board as shown in Fig. 1 and 2, with long stout screws, so as to divide the keel into three nearly equal parts. Then add the stem and stern pieces (C, C, Fig. 2). These are better, probably, when made of green elm. Screw the pieces to the bottom-board and bend them, as shown in Fig. 2, by means of a string or wire, fastened to a nail driven into the bottom. Any tough, light wood that is not easily broken when bending will do. Green wood is preferable, because it will retain the shape in which it has been bent better after drying. For the gunwales (a, a, Fig. 3), procure at a carriage factory, or other place, some tight strips of ash, 3/8 in. thick. Nail them to the crossboards and fasten to the end pieces

[Ill.u.s.tration: Important Features of Construction]

(C, C,) in notches, by several wrappings of annealed iron wire or copper wire, as shown in Fig. 3. Copper wire is better because it is less apt to rust. For fastening the gunwales to the crossboards use nails instead of screws, because the nails are not apt to loosen and come out. The ribs, which are easily made of long, slender switches of osier willow, or similar material, are next put in, but before doing this, two strips of wood (b, b, Fig. 3) should be bent and placed as in Fig. 3. They are used only temporarily as a guide in putting in the ribs, and are not fastened, the elasticity of the wood being sufficient to cause them to retain their position. The osiers may average a little more than 1/2 in. in thickness and should be cut, stripped of leaves and bark and put in place while green and fresh. They are attached to the bottom by means of s.h.i.+ngle nails driven through holes previously made in them with an awl, and are then bent down until they touch the strips of ash (b, b, Fig. 3), and finally cut off even with the tops of the gunwales, and notched at the end to receive them (B, Fig. 4). Between the cross-boards the ribs are placed at intervals of 2 or 3 in., while in other parts they are as much as 5 or 6 in. apart. The ribs having all been fastened in place as described, the loose strips of ash (b, b, Fig. 3) are withdrawn and the framework will appear somewhat as in Fig. 1. In order to make all firm and to prevent the ribs from changing position, as they are apt to do, buy some split cane or rattan, such as is used for making chair-bottoms, and, after soaking it in water for a short time to render it soft and pliable, wind it tightly around the gunwales and ribs where they join, and also interweave it among the ribs in other places, winding it about them and forming an irregular network over the whole frame. Osiers probably make the best ribs, but twigs of some other trees, such as hazel or birch, will answer nearly as well. For the ribs near the middle of the boat, twigs 5 or 6 ft. long are required. It is often quite difficult to get these of sufficient thickness throughout, and so, in such cases, two twigs may be used to make one rib, fastening the b.u.t.ts side by side on the bottom-board, and the smaller ends to the gunwales, as before described. In drying, the rattan becomes very tight and the twigs hard and stiff.

The frame-work is now complete and ready to be covered. For this purpose buy about 18 yd. of very strong wrapping-paper. It should be smooth on the surface, and very tough, but neither stiff nor very thick. Being made in long rolls, it can be obtained in almost any length desired. If the paper be 1 yd. wide, it will require about two breadths to reach around the frame in the widest part.

Cut enough of the roll to cover the frame and then soak it for a few minutes in water. Then turn the frame upside down and fasten the edges of the two strips of paper to it, by lapping them carefully on the under side of the bottom-board and tacking them to it so that the paper hangs down loosely on all sides. The paper is then trimmed, lapped and doubled over as smoothly as possible at the ends of the frame, and held in place by means of small clamps. It should be drawn tight along the edges, trimmed and doubled down over the gunwale, where it is firmly held by slipping the strips of ash (b, b) just inside of the gunwales into notches which should have been cut at the ends of the cross-boards. The shrinkage caused by the drying will stretch the paper tightly over the framework. When thoroughly dry, varnish inside and out with asphaltum varnish thinned with turpentine, and as soon as that has soaked in, apply a second coat of the same varnish, but with less turpentine; and finally cover the laps or joints of the paper with pieces of muslin stuck on with thick varnish. Now remove the loose strips of ash and put on another layer of paper, fastening it along the edge of the boat by replacing the strips as before. When the paper is dry, cover the laps with muslin as was done with the first covering. Then varnish the whole outside of the boat several times until it presents a smooth s.h.i.+ning surface. Then take some of the split rattan and, after wetting it, wind it firmly around both gunwales and inside strip, pa.s.sing it through small holes punched in the paper just below the gunwale, until the inside and outside strips are bound together into one strong gunwale. Then put a piece of oil-cloth in the boat between the cross-boards, tacking it to the bottom-board. This is done to protect the bottom of the boat.

Now you may already have a canoe that is perfectly water-tight, and steady in the water, if it has been properly constructed of good material. If not, however, in a few days you may be disappointed to find that it is becoming leaky. Then the best remedy is to cover the whole boat with unbleached muslin, sewed at the ends and tacked along the gunwales. Then tighten it by shrinking and finally give it at least three coats of a mixture of varnish and paint. This will doubtless stop the leaking entirely and will add but little to either the weight or cost.

Rig the boat with wooden or iron row locks (B, B, Fig. 5), preferably iron, and light oars. You may put in

[Ill.u.s.tration: Off for a Hunt]

several extra thwarts or cross-sticks, fore and aft, and make a movable seat (A, Fig. 5.) With this you will doubtless find your boat so satisfactory that you will make no more changes.

For carrying the boat it is convenient to make a sort of short yoke (C, Fig. 5), which brings all the weight upon the shoulders; and thus lightens the labor and makes it very handy to carry.

** To Hang Heavy Things on a Nail [323]

Boys will find many places around

[Ill.u.s.tration: Double Nails]

the house, where a hook to hang things on will be a great convenience. Instead of buying hooks use wire nails, and if driven as shown in the cut, they will support very heavy weights. Drive the lower nail first.

** A Home-Made Elderberry Huller [324]

As we had only one day to pick elderberries, we wanted to get as many of them as we could in that time. We could pick them faster than they could

[Ill.u.s.tration: Details of the Elderberry Huller]

be hulled by hand so we made a huller to take along with us to hull the berries as fast as they were picked. We procured a box and made a frame, Fig. 1, to fit it easily, then made another frame the same size and put a piece of wire mesh between them as shown in Fig. 2, allowing a small portion of the mesh to stick out of the frames. The top frame would keep the berries from rolling or jumping off, and the bottom frame kept the wire mesh and frame from being shaken off the box. The projecting edges of the mesh would keep the frame on the top edge of the box. The top view of the frame is shown in Fig. 1 and the end in Fig. 5, and the box on which the frame rests in Fig. 3. The actual size of the wire mesh used is shown in Fig. 4. One person could hull with this huller as many berries as two persons would pick.

--Contributed by Albert Niemann, Pittsburg, Pa.

** How to Make a Bulb on a Gla.s.s Tube [324]

As a great many persons during the winter months are taking advantage of the long evenings to experiment in one way or another, the following method of forming bulbs on gla.s.s tubes may be of interest. A common method is to heat the part to be formed and by blowing in one end of the tube gradually expand the gla.s.s.

This way has its drawbacks, as many are not sufficiently familiar with the work to blow a uniform blast, and the result is, a hole is blown through the side of the tube by uneven heating or blowing.

A good way to handle this work, is to take the tube and 1 or 2 in.

more in length than the finished article is to be and place one end over an alcohol flame, and by holding a spare piece of tubing against the end allow them both to come to a melting heat, then pull apart and instead of breaking off the long thread thus formed, simply hold it in the flame at an angle of 45 deg. and melt it down and close the end at the same time. Close the other end with the same operation; this makes the tube airtight.

Gradually heat the tube at the point where the bulb is to be formed, slowly turning the tube to get a uniform heat. The air inside of the tube becoming heated will expand, and the gla.s.s, being softer where the flame has been applied, will be pushed out in the shape of a bulb. A great deal of care should be taken not to go to extremes, as the bulb will burst with a loud report if the heat is applied too long. The best results are obtained by heating the gla.s.s slowly and then the bulb can be formed with regularity. This is an easy way to make a thermometer tube. After the bulb is formed, the other end of the tube can be opened by heating, drawing out and breaking the thread like gla.s.s.

--Contributed by A. Oswald.

** How to Make a Sconce [325]

A sconce is a candlestick holder, so made that it has a reflector of bra.s.s or copper and is to hang upon the wall. The tools necessary are a riveting hammer, file, metal shears, rivet punch, flat and round-nosed pliers, screwdriver and sheet bra.s.s or copper No. 23 gauge.

To make the sconce proceed as follows: First, cut off a piece of bra.s.s so that it shall have 1/2 in. extra metal all around; second, with a piece of carbon paper, trace upon the bra.s.s lines that shall represent the margin of the sconce proper, also trace the decorative design; third, with a nail set make a series of holes in the extra margin about 3/4 in. apart and large enough to take in a 3/4-in. thin screw; fourth, fasten the metal to a thick board by inserting screws in these holes; fifth, with a twenty-penny wire nail that has had the sharpness of its point filed off, stamp the background of the design promiscuously. By holding the nail about 1/4 in. above the work and striking it with the hammer, at the same time striving to keep its point at 1/4 in.

above the metal, very rapid progress can be made. This stamping lowers the background and at the same time raises the design.