Fig. 130
The drawing for the particular hull shown inFig. 130is given inFig. 131. First the two side pieces are cut out to the shape shown. In this particular instance the over-all length of the sides is 391/3inches. This is called a meter boat, and is built with this length to conform with the English racing rules. Next a bow piece is cut out, and this is produced from solid wood. Only two materials are used in the construction of this hull, aluminum and mahogany. Square mahogany strips are cut out and fastened inside of the side pieces by meansof shellac and3/8-inch brass brads. The bottom of the hull is made of 22-gage sheet aluminum. This is fastened to the square mahogany strips, since the sides of the boat are entirely too thin for this purpose. The method of fastening the strips of aluminum will be made evident by referring toFig. 132. The aluminum bottom does not run completely over the bow piece, but merely overlaps it sufficiently to be fastened by brass brads, as illustrated inFig. 135. The singlestep in the bottom of the boat is fastened by a mahogany strip, through which the stern-tube runs and the water-scoop. The back of the boat is made up of mahogany. A small aluminum hood is bent to shape, and this is fastened to the bow of the boat and prevents the boat from shipping water.
In building a hull of this nature the mechanic should exercise care to see that it is in perfect balance, and that the sides are finished and varnished as smoothly as possible. This will cut down both air and water resistance. The position of the propeller strut and stern-tube will be seen by referring to the drawing of the hull inFig. 131.
The propeller of a high-speed boat is of a high pitch and generally of the two-blade type. It should be at least 3 inches in diameter and with a pitch of about 10 inches. By this it is meant that the propeller theoretically should advance 10 inches through the water for one revolution. The rudder is generally fastened in one position, in case the boat is not used on a string and pole. It will be found advisable, however, always to run the boat in this way, and in such casesthe rudder can be entirely dispensed with.
Fig. 133
The boiler of a flash steam plant is extremely simple. Such a boiler is shown inFig. 133. It consists merely of a coil of copper or Shelby steel tubing with an internal diameter of1/4inch. The boiler coils should be wound around a circular form of wood about 23/4inches in diameter. In the case of copper it will not be found very difficult to do this, providing the copper is heated before being wound on the wooden form. If the copper is heated it is advisable to wind the wood with a layer of sheet asbestos before the copper tube is wound on. It is almost necessary to do this winding with a lathe, but if the mechanic does not have access to such a tool he may have to find other means of doing it, or possibly he can take it to a local machine shop and havethe work done for a few cents. The boiler coil should be wound about 9 inches long.
A casing of Russian sheet iron is made to slip over the boiler, leaving sufficient space between. Ventilating holes or slots are cut in the cover to permit of a free circulation of air. The boiler covering is also provided with a funnel through which the exhaust gases from the blow-lamp pass.
Fig. 134
The blow-lamp used operates on the same principle as the ordinary blow-torch. The details of such a lamp are given inFig. 134, and a finished torch is shown inFig. 135. Instead of making the valves necessary for the blow-torch, it is advisable to purchase them, for they are very difficult to make accurately. The valve at the back of the torch regulates the gasolene supply that passes through the nipple. The hole in thenipple should be about twenty thousandths of an inch. Owing to the fact that the copper coil wound about the burner is short, the tube can be filled with molten resin before it is bent. In this way the tube will not kink or lose its shape while being wound. After it is wound it is placed in the fire and the molten resin forced out with a bicycle-pump. Such a blow-torch produces a tremendous heat and throws a hot flame far up into the boiler coils.
BEFORE attempting to construct model sailing yachts the young worker should become thoroughly conversant with the different types of yachts and their fittings. In the following pages the author briefly outlines the general science of yacht-making and sailing.
Sailing yachts are made in four principal types. There is the cutter rig, yawl rig, sloop rig, and the ketch rig. The cutter rig is shown inFig. 136. It consists of four sails so arranged that the top-sail may be either removed altogether or replaced by sails of smaller area. In all yachts it is necessary to haul the sails up into position by ropes known as halyards. The halyards must be led down to the deck. The model-builder, however, can dispense with much of the gear used on larger boats.
A sloop rig is illustrated inFig. 137. By studying the drawing the worker will see that the sloop rig differs from the cutter rig only in that she carries a single sail forward of her mast.
Fig. 137
The yawl rig (SeeFig. 138) is similar to a cutter rig, but has a small sail set up on another mast abaft the mainsail. The sheet is led aft to a spar that projects beyond the counter. The mast upon which the smaller sail is set is known as the mizzenmast. In this rig it will be seen that the main boom must be made considerably shorter than wasthe case in the cutter rig. This is done so that it will not follow the mizzenmast when it swings from one position to another.
Fig. 138
The ketch rig differs greatly from the yawl rig. The mizzenmast always occupies a position forward of the rudder-post. In the yawl the mizzenmast is always stepped aft of the rudder-post. This will be seen by referring to the drawings of the two boats. The ketch rig is illustrated inFig. 139.
The prettiest rig of all is the schooner; but, owing to the fact that it is difficult to get them to go well to windward unless thehull is perfectly rigged, the author has decided not to deal with this type of boat. When the reader becomes proficient in building and sailing the simpler types described in this book, he may turn his attention to the construction and sailing of more complicated types.
Model Yacht Parts
The submerged portion of a yacht is, as in all other boats, termed the hull. The backbone of the hull is called the keelson. Attached to the keelson is a piece of lead, which is put in place to give the boat stability and power to resist the heeling movement created by the wind-pressure upon the sails. This is known as the keel.
Yachts always have an opening in the deck giving access to the interior of the hull. These openings are known as hatchways. When sailing in rough weather the hatchway is closed by a hatch to prevent the yacht from shipping water.
The extreme forward end of a yacht hull is called the stern, while the portions forwardand aft of the midships section are known as the fore and after-body respectively.
A TWIN CYLINDER STEAM ENGINE FOR MODEL MARINE USEA TWIN CYLINDER STEAM ENGINE FOR MODEL MARINE USEThis engine will drive a boat several feet long
In all yachts a portion of the hull extends out over the water. These portions are known as overhangs. The overhang aft is sometimes called the counter-stern. The sides of the hull that rise above the deck are called bulwarks, and the part of the bulwarks that cross the stern is called the taffrail. The taffrail is always pierced with holes to allow water to run off the deck quickly, so that the additional weight will not in any way affect the course of the boat. It is understood that yachts raise great quantities of water upon their decks when traveling in rough sea.
The bowsprit is passed through a ring at the top of the stern, and this ring is termed the gammon iron. Its end is secured in a socket or between a pair of uprights called the bowsprit bits. These are fixed to the deck. Metal bars are fixed a short distance above the deck to take rings attached to the sheets. This is done so that the sails may swing freely from one side of the boat to theother. Metal eyes are screwed into the sides to take the shrouds, and are called chain-plates. The eye in the stern is called the bobstay plate. In the stern-post are two eyes called gudgeons. The rudder is hooked to this by means of two hooks called pintles. The bar or lever that is fixed to the top of the rudder-post is called a tiller.
A CUP-WINNING MODEL SAIL BOATA CUP-WINNING MODEL SAIL BOATDesigned and constructed by the commodore of the Central Park Model Yacht Club, New York, N. Y.
The parts and fittings of a mast follow: the step, the head, the caps, crosstrees, truck, topmast, boom, and gaff. The part of the gaff that rests on the mast is called the throat; the end of the gaff is called the peak. The jib-boom is a term used only in connection with model yachts. In larger boats the jib-boom is an extension of the bowsprit. The small boom that projects over the stern of a yawl is called the bumpkin. The spar is rather a general term applied to practically all wooden supports of sails. The spar of a lug-sail is called the yard. It is different from a boom or gaff, by reason of its lying against the mast instead of having one end butting on the mast. Anything belonging to the mainmast should be distinguished by the prefix main. Thus, there are themainsail, the mainboom, main-topsail, etc.
Fig. 140
A sail for a model cutter-rigged yacht is shown inFig. 140. The bowsprit and masts are, when necessary, given support by ropes that are stretched tightly to some point where they can be conveniently anchored to the hull. The following are those largely used on model yachts: topmast stay, bobstay, topmast shrouds, and forestay.
The sails are pulled up and fastened by ropes termed halyards. The halyards are fastened to the upper portions of the sail, and they are named according to the sail to which they are attached. For instance,there is the jib halyard and the foresail halyard. A mainsail carried by a gaff has two halyards, the throat and peak. The movement of the sails is controlled by ropes, called sheets, which take their names from the sails they control. There is a mainsheet, a jibsheet, and a foresheet. The reader should take note of this term and refrain from confusing it with the sails.
Sailing Model Yachts
The sailing of model yachts is a real art, and the author warns the reader that he cannot hope to become a proficient yachtsman by merely digesting the information given in this book. His real knowledge must be earned by experience in handling a model yacht on the water. However, there are few sports that will afford more pleasure than that of sailing model yachts. Being an outdoor sport it is very healthful.
In sailing a model yacht the sails are set, or "trimmed," so that she will continue to sail along the course previously decided upon by the yachtsman. She must do this in asspeedy a manner as possible and with as little deviation from her original course as possible. The trim of the sails will depend upon the wind. If the boat is to sail against the wind, that is termed "beating to windward"; with the wind is called "scudding." With the wind sideways it is called "reaching." If the boat is sailed with the wind blowing midway between one of the sides and the stern in such a way that it sweeps from one side of the stern across the deck, this is called "three-quarter sailing" in a "quartering" wind. A model yacht will continue for a great distance on a reach or while scudding; but, on the other hand, it will not be possible for her to sail directly against the wind. If a yachtsman is to make headway against the wind, he must sail his boat as near dead against the wind as it will go.
The cutter type of yacht will move against a wind that is blowing at a very small angle on her bowsprit. As soon as she reaches the limit of her course, the yachtsman turns her bow at a small angle so as to bring the wind on the opposite side of the vessel, andin this way a second course is started. These courses are repeated in a zigzag fashion until the yacht arrives at her destination. This zigzagging, or "tacking," as it is called, is illustrated inFig. 141. It will be seen that the yacht starts atB, and makes 3 tacks before she arrives at her destination,A. Each time she touches the shore she is "put about" and set upon a new course, or "tack."
Fig. 141
It will be understood that tacking is slow work, and a greater distance must be traveled than would be covered by a power-boat, which would be able to go in a straight line. However, with wind-propelled craft this is the only way in which progress can be made against the wind. The left-hand side of a yacht viewed from the stern is called the port side, while the right-hand side is calledthe starboard side. Thus a yacht sailing with the wind blowing on her port side is on the port tack, while if the wind is blowing on the starboard side she is said to be on the starboard tack. From this the reader will see thatFig. 142shows an impossible case.
Fig. 142
The sails in front of the mast that are placed nearest the stern of the yacht act in such a manner as to turn the bows in the direction of the arrow, as illustrated in Fig.146, and the sail or sails abaft the mast turn the boat in the direction of the arrowA. The boat thus revolves upon the center of the mast much as a weathercock revolves upon its pivot. If there is more than one mast, all the sails carried abaft the mainmast serve to turn the boat in the directionA. The work of sailing depends greatly upon the skill in balancing these two effects so that the boat will progress in a straight line. To do this the sails are set in a greater or less angle in relation to the center line of the boat. The less the angle that a sail makes with the center line of the boat, the greater is its power to determine in which direction the boat will steer. The more the yachtsman slackens out his jib and foresail, or the smaller he makes these sails, the less their power will be to turn the boat in the directionB. On the other hand, the larger they are and the more tightly they are pulled in, the greater will be their power. When the mainsail and all of the sails abaft the mainsail are slackened out and the smaller they are made, the less their power will be to swing the boat in the directionA.
The influence of a sail upon the speed of a boat also increases with the angle that it makes with the center line of the hull. The more the yachtsman slackens out his sail, the more it will help the boat along. The reader will see that these two conditions interfere with each other, and therefore the trimming of the sails becomes a compromise. It is good for the young yachtsman to remember to sail his boat with the sails as slack as possible, as long as she keeps a good course. He should also remember not to overload her with sails, since the nearer to an upright position she maintains the faster she will go.
It is not possible to depend entirely upon the trim of the sails to keep a model in a given course. This is because the strength of the wind varies so that the sails are in balance one moment and out of balance the next. The sails abaft the mainmast overpower the sails before it when the wind increases. The result of this is that the bow of the boat will be repeatedly turned in the directionA,Fig. 146.
Fig. 146
Some form of automatic rudder is thereforegenerally used to overcome this tendency of the yacht to "luff" in the wind.Fig. 147shows the course of a yacht reaching fromAtoB. The dotted lines show the course she should follow. The full line shows the effect of puffs of wind, which repeatedlytake her out of her course. Many times she may completely turn around and make a similar course back to the starting-point, as inFig. 148. There is also the danger of her being taken back when pointing directly against the wind—the wind will force her backward stern first for some distance, as illustrated inFig. 149. She will do this until she manages to get around on one tack or the other.
The dotted lineBillustrates the course in which she would be driven under these conditions. It is not practical to sail a model yacht dead before the wind without an automatic rudder. With the use of an automatic rudder the erratic movements shown inFig. 148can be entirely overcome. The action of the rudder is such that every time the boat leans over to luff up into the wind, the weight of the rudder causes it to swing out, and thus prevents her from losing her course. As a different type of rudder is required, according to the course in which the yacht is sailing, the weight should be adjustable if the same rudder is used.
Fig. 149
Let us consider scudding before the wind.For scudding the heaviest rudder should be used, or the weight on a loaded tiller should be in its position of maximum power. All the sails abaft the foremast should be slackened out as far as they will go, which will bring the booms almost at right angles with the center line of the boat. If the craft is a cutter or yawl with a light weight, the yachtsman should rig the spinnaker. The head-sails may be left slack or can be tightened.Fig. 150shows the position of thebooms when scudding with a schooner and yawl. The yawl is shown scudding goose winged. The cutter is illustrated with the spinnaker set. The other craft is a two-mast lugger with balanced lugs.
Fig. 151
Attention is now directed to "reaching." For this particular work the yachtsman should put on a medium rudder. When using a weighted tiller the weight should be put in a midway position. The head-sails should be pulled in fairly tight and the aft-sails made slack. The yachtsman, however, should not slacken them as for scudding.Fig. 151shows a schooner reaching. The thick black lines represent the booms of the sails. If the wind is very light a spinnaker-jib may be set or a jib-topsail in light or moderate breezes. In the case of a windthat comes over the stern quarter, as indicated by the arrowA, the next heavier rudder, or its equivalent in weighted tiller, should be put in operation, and the sails slackened out a little more than before. The boat is then said to be free and sailing on the starboard tack. If the wind is coming in the directionBthe jib and foresail may require slackening and the aft sails pulled in more than when sailing with the wind in the directionC. A still lighter rudder can be used as the course gets near to beating windward, and the yacht is said to be close-hauled on the starboard tack.
In beating to windward, if a rudder is used at all, it should be as light as possible, just heavy enough to keep the boat steady. However, this is just the condition of sailing when a boat can dispense with a rudder. It depends entirely upon the characteristics of the particular yacht being sailed, and for this the yachtsman must depend upon his own experience. The jib-topsail should not be used in a case like this, and if the wind is fairly strong a smaller jib should be set than that used for reaching. It is advisableto slacken the jib and foresail out and pull the aft-sails in somewhat tightly.Fig. 152shows a cutter beating to windward on a port tack. In this case she will have to pay out to starboard a bit before her sails fill.
In sailing the weather must be watched very closely, and the amount of sail carried will depend entirely upon the weather conditions. A yacht should never be overloaded with sail. If she has more than she can comfortably carry she will heel over and drag her sails in the water. Not only this, but she will also drift to leeward when beating to windward. When sailing a new boat, her best trim for various points of sailing and force of wind must be found by painstaking experiments. The boat should always be sailed with her sails as slack as she will take them and keep in her course. In this way she will move faster than when the sails are pulled in close.
The model yachtsman should always watch the wind and note whether it shifts its direction or alters its force. The boat is trimmed accordingly when the boat is put about. Easing or tightening the jib ormain-sheet slightly will make a very noticeable difference.
By taking down the top-sail or setting a jib-head top-sail in place of a jack yard top-sail, the yacht will be caused to ride easier in puffs of wind. In case she does not point well to windward when beating, the yachtsman should try a smaller jib, or he can slacken the foresail-sheet. If she runs off regularly to leeward on one tack only, while keeping well to windward on the other, she has some defect in construction or a bent keel.
THE model yacht described in this Chapter is the design of Mr. W. J. Daniels, of England, and was described by him in "Junior Mechanics." Mr. Daniels is one of the best known and most successful English designers of model yachts, and the one here described can easily be constructed by the average boy:
In order that the reader may realize the obstacles to be surmounted in designing a model yacht that will sail in a straight line to windward, irrespective of the different pressure that the wind may expend on the sails, it must be pointed out that the boat is continuously altering the shape of the submerged part of her hull: therefore, unless the hull is so designed that harmony is retained at every angle to which the pressure of wind on the sails may heel it, the model's path through the water will be, more or less, an arc of a circle. Whether the boat sails toward the wind, or, in other words, in a curve thecenter of the circle of which is on the same side of the boat as the wind, or in a curve the center of the circle of which is on the opposite or leeward side, will depend upon the formation of the boat.As these notes are intended to first initiate the reader into the subject of model yacht building and construction, the design supplied is one in which all things, as far as shape is concerned, have been considered.It is the endeavor of every designer to produce the most powerful boat possible for a given length—that is, one that can hold her sail up in resistance to the wind-pressure best. Of course, the reader will easily realize that breadth and weight of keel will be the main features that will enable the model to achieve this object; but, as these two factors are those that tend to make a design less slender, if pushed to extremes, the designer has to compromise at a point when the excess of beam and buoyancy aredetrimentalto the speed lines of the hull.But the question of design pure and simple is a complex one, and we do not intend to weary the reader just now with anything of that kind, so we will now proceed to build the hull. In order that we may correctly interpret the shape shown in the design without being expert woodcarvers, we must use our ingenuity and by mechanical means achieve our object, at the same time saving ourselves a large amount of labor, such as we should have toexpend if we made this boat from a solid block of wood.Now, as regards understanding the drawings: it is essential to remember that a line which in one view is a curve is always a straight line in the other two views. Those lines which are drawn parallel to the water-line are known as water-lines, and it will be seen that the curves shown on the deck plan represent the actual shapes of the hull at the corresponding water-lines above, below, and exactly on the load water-line. In other words, if after the hull is made it were sunk down to these various levels, the shapes of the hole made in the surface of the water would be as shown in the plan.Therefore, instead of making our boat from a solid block of wood, we will make our block up from several layers, the thickness of each layer being equal to the space between the water-lines; but before gluing these layers together we will cut them out to the exact shape that the boat will be at their various positions.It will not be necessary to have a separate piece of wood for each layer, as some layers below the actual water-line will be cut from the pieces of wood that have been cut out from the layers above.In this case, the boat being 24 inches long, the top layer will be the same length and breadth as the boat, and 1 inch in thickness.Draw down the center of the board a straightline, and other lines square to it, representing the position of the cross-sections as shown in the drawing. You have now to transfer the deck line to this board, and this is done by marking the breadth at the various sections and drawing a curve through the spots, a thin strip of straight-grained wood being used as a rule, the latter being held down by such weights as are available. For the purpose of laying off the water-lines truly, lines spaced at 11/2inches are shown; the first, it will be noticed, is half a section or3/4inch from the stem head.The material required will be a board of pine about 6 feet long, 8 inches wide, and 1 inch finished thickness.Nearly all wood-yards stock first-quality pine, but it is in planks 3 inches thick. You can no doubt pick up a short length about 4 feet long.If so, take it to a sawmill and have two boards 11/4inches thick cut and then machine-planed down to a dead inch. Perhaps you can purchase a board that is already cut, and is fully 1 inch thick, to allow for planing.Prepare one edge of the board straight with a plane, seeing that it is square to the surface.As a planing-machine always leaves a series of ridges across the board, varying according to the quality of the machine, it is necessary before transferring the lines to the wood to just skim the surface with a nicely sharpened plane, and set so as to just skim the wood.
In order that the reader may realize the obstacles to be surmounted in designing a model yacht that will sail in a straight line to windward, irrespective of the different pressure that the wind may expend on the sails, it must be pointed out that the boat is continuously altering the shape of the submerged part of her hull: therefore, unless the hull is so designed that harmony is retained at every angle to which the pressure of wind on the sails may heel it, the model's path through the water will be, more or less, an arc of a circle. Whether the boat sails toward the wind, or, in other words, in a curve thecenter of the circle of which is on the same side of the boat as the wind, or in a curve the center of the circle of which is on the opposite or leeward side, will depend upon the formation of the boat.
As these notes are intended to first initiate the reader into the subject of model yacht building and construction, the design supplied is one in which all things, as far as shape is concerned, have been considered.
It is the endeavor of every designer to produce the most powerful boat possible for a given length—that is, one that can hold her sail up in resistance to the wind-pressure best. Of course, the reader will easily realize that breadth and weight of keel will be the main features that will enable the model to achieve this object; but, as these two factors are those that tend to make a design less slender, if pushed to extremes, the designer has to compromise at a point when the excess of beam and buoyancy aredetrimentalto the speed lines of the hull.
But the question of design pure and simple is a complex one, and we do not intend to weary the reader just now with anything of that kind, so we will now proceed to build the hull. In order that we may correctly interpret the shape shown in the design without being expert woodcarvers, we must use our ingenuity and by mechanical means achieve our object, at the same time saving ourselves a large amount of labor, such as we should have toexpend if we made this boat from a solid block of wood.
Now, as regards understanding the drawings: it is essential to remember that a line which in one view is a curve is always a straight line in the other two views. Those lines which are drawn parallel to the water-line are known as water-lines, and it will be seen that the curves shown on the deck plan represent the actual shapes of the hull at the corresponding water-lines above, below, and exactly on the load water-line. In other words, if after the hull is made it were sunk down to these various levels, the shapes of the hole made in the surface of the water would be as shown in the plan.
Therefore, instead of making our boat from a solid block of wood, we will make our block up from several layers, the thickness of each layer being equal to the space between the water-lines; but before gluing these layers together we will cut them out to the exact shape that the boat will be at their various positions.
It will not be necessary to have a separate piece of wood for each layer, as some layers below the actual water-line will be cut from the pieces of wood that have been cut out from the layers above.
In this case, the boat being 24 inches long, the top layer will be the same length and breadth as the boat, and 1 inch in thickness.
Draw down the center of the board a straightline, and other lines square to it, representing the position of the cross-sections as shown in the drawing. You have now to transfer the deck line to this board, and this is done by marking the breadth at the various sections and drawing a curve through the spots, a thin strip of straight-grained wood being used as a rule, the latter being held down by such weights as are available. For the purpose of laying off the water-lines truly, lines spaced at 11/2inches are shown; the first, it will be noticed, is half a section or3/4inch from the stem head.
The material required will be a board of pine about 6 feet long, 8 inches wide, and 1 inch finished thickness.
Nearly all wood-yards stock first-quality pine, but it is in planks 3 inches thick. You can no doubt pick up a short length about 4 feet long.
If so, take it to a sawmill and have two boards 11/4inches thick cut and then machine-planed down to a dead inch. Perhaps you can purchase a board that is already cut, and is fully 1 inch thick, to allow for planing.
Prepare one edge of the board straight with a plane, seeing that it is square to the surface.
As a planing-machine always leaves a series of ridges across the board, varying according to the quality of the machine, it is necessary before transferring the lines to the wood to just skim the surface with a nicely sharpened plane, and set so as to just skim the wood.
Fig. 153
The lengths required are:A, plank 24 inches long;B, plank 24 inches;C, plank 181/2inches.TheDplank will be cut from the center ofB, but will have to be shifted two sections forward.Having transferred the various shapes from the drawing on to their respective layers, you saw out each carefully with a bow or a keyhole-saw, care being taken not to cut inside the lines. It is better to cut full, and trim down to the lines with a chisel or plane. A good deal of trouble can be saved by the expenditure of a few cents for having them machine-sawed, in which case ask the sawyer to use his finest-toothed saw.Having cut out layersA,B,C, andD, fresh lines are marked, as shown by the dotted lines in the plan. These indicate the shape of the inside of each layer when the boat is carved out, and save labor.These may as well be sawed out now as carved out later. It will also facilitate gluing up, as it will allow the superfluous glue to be squeezed out, and also decrease the breadth of the joint.In order to get these various layers glued together dead true to their positions as indicated in the design, you must choose a section about amidships, say section 11, and with a square draw a line from that section, which is, of course, still showing on the surface of the layer, down the edge on either side, joining up with a line across the opposite face. Also vertical lines at each end of themidships line must be drawn on the wood, great care being taken to get the midships line on the under face of the layers dead opposite each other.
The lengths required are:A, plank 24 inches long;B, plank 24 inches;C, plank 181/2inches.
TheDplank will be cut from the center ofB, but will have to be shifted two sections forward.
Having transferred the various shapes from the drawing on to their respective layers, you saw out each carefully with a bow or a keyhole-saw, care being taken not to cut inside the lines. It is better to cut full, and trim down to the lines with a chisel or plane. A good deal of trouble can be saved by the expenditure of a few cents for having them machine-sawed, in which case ask the sawyer to use his finest-toothed saw.
Having cut out layersA,B,C, andD, fresh lines are marked, as shown by the dotted lines in the plan. These indicate the shape of the inside of each layer when the boat is carved out, and save labor.
These may as well be sawed out now as carved out later. It will also facilitate gluing up, as it will allow the superfluous glue to be squeezed out, and also decrease the breadth of the joint.
In order to get these various layers glued together dead true to their positions as indicated in the design, you must choose a section about amidships, say section 11, and with a square draw a line from that section, which is, of course, still showing on the surface of the layer, down the edge on either side, joining up with a line across the opposite face. Also vertical lines at each end of themidships line must be drawn on the wood, great care being taken to get the midships line on the under face of the layers dead opposite each other.
Fig. 154
If your outfit contains half a dozen carpenter's hand screws, these can be used; but if not, it will be necessary to purchase from a hardware storeeight seven-inch bolts and nuts3/8inch in diameter, with one washer for each, and to make up four clamps, as shown inFig. 156.
If your outfit contains half a dozen carpenter's hand screws, these can be used; but if not, it will be necessary to purchase from a hardware storeeight seven-inch bolts and nuts3/8inch in diameter, with one washer for each, and to make up four clamps, as shown inFig. 156.
Fig. 156
You will start by gluing layerCto layerD, blocks being placed between the surface of the layers and the clamps to prevent bruising the wood. These two are then glued to layerB, and when this is thoroughly set they are glued to the layerA. The best glue to use for this job is marine glue, which does not dry too quickly, and so gives plenty of time to see that the layers have not shifted. In every case one clamp should be placed at each extreme end of the shorter layer, so as to insure the ends making contact, the other two being placed equidistant.While waiting for the glue to set, you can be preparing the four layers (shown belowD) for the lead keel pattern. The lines must be cut out, in this case, with a chisel, as it will be noticed that thelower faces must be left wide enough to receive the top face of the layer beneath it.It will be noticed that the under face of each of these layers extends beyond the top face aft, and allowance must be made for this. On laying off the lines on the fin layers, do not join up with a point each end, but leave about1/8inch thickness, as shown on the drawing.These layers must be drilled through to take the keel-bolts, which are made from two motorcycle spokes, twelve-gage. These should be cut to a length of 51/2or 6 inches. Great care should be taken to insure that the midship lines are exactly vertical over each other when these layers are glued up.Before gluing these four layers on to the hull proper, they should be held in position by means of the spokes, in which position they can be sawed to shape for the keel pattern. First, with a small plane or sharp chisel cut down roughly, then a rasp and different grades of sandpaper are used, working across the joints.It will be realized that, if the pattern for the keel were cut off dead on the line indicated on the design, there would be a loss of wood through the saw cut. In order to obviate this, another line3/16inch below the proper lead line is drawn, and the saw cut made between these two lines. You will now plane down each face that is left rough by the saw, straight and square to each of these lines.On the top face of the pattern for the lead, glue or tack a piece3/16inch thick along the face, and cut down the edges flush.You will by this means have made up for the amount of wood carried away by the saw. You will no doubt find a difficulty in holding the pieces of wood for planing in the ordinary way, but it is simple enough if you set the plane nicely, grip it in a vise or bench screw upside down, and push the work over the plane's face, instead of vice versa. But be careful of your fingers!Take the pieces left from the spokes when cutting down to length, and put these in the holes in the keel pattern. These are for cores, and if you take your pattern to a foundry they will cast it for a small amount, with the holes in it.Shoot the top face of the lead in the manner before described, and fit on. The hull is now ready for carving out. Screw on your bench two pieces of wood about 18 inches in length and 4 inches wide, so that they project over the edge of the bench about 10 inches. These should be about 15 inches apart. Place your hull upside down on them, and fix it by nailing upward into the top layer. After cutting off the corners of the layers roughly with a chisel you use a small plane set fairly fine, and work all over the hull evenly, taking care not to cut below any of the joints. A small gouge will be required to clear the wood from the region of the after fin, a round rasp—sandpaper beingwrapped around a small stick—being used for smoothing down afterward.Templates of the cross-sections should now be made from thick white paper. This is done by pricking through the design to transfer their shape onto the paper. The cross-sections have on this account been produced here actual size. If cross-lines representing the water-lines are drawn, you will have an excellent guide for fitting, as these lines will, of course, come opposite each glued joint.Try your templates now and again as you work, and do not try to finish one spot, but keep the whole at an even stage, and you will see the hull gradually grow into shape.The topsides (which is the name given to that part of the vessel's hull above the water-line) are responsible for the boat's appearance when afloat, and until the top sheer is cut off the boat looks very disappointing. The cross-lines being still on the upper layer, draw square lines from them down the topsides and from the drawing mark the points through which the sheer-line runs. The thickness of the deck must be allowed for, and as this will be just over1/16inch, the line must be drawn this much below the finished sheer-line. The arch of the transom must be marked, and the hull cut down to the sheer. To avoid the risk of splitting, a number of fine saw cuts are made down each section line and two or three at the transom.You now proceed to carve out the inside. Padyour bench bearers and rest your hull upon them. A curved wood gouge with a fairly flat edge is the best tool. Get it nicely sharpened, and work all over the inside of hull until it is about3/16inch thick, the top edge being left3/8inch wide.Keep holding up to the light until it is showing a blood-red color, and smooth down the gouge marks with coarse sandpaper.The hole for the stern-tube must now be drilled, and the tube made and fitted. The hole should be1/4inch in diameter. First drill a smaller hole, and then with a1/4-inch rat-tail file slowly open it out, at the same time rubbing a groove down the stern-post. The stern-tube is made from a piece of light-gage brass tube, it being cut away with a piercing saw to leave a strip the length of the stern-post. Drill three holes in the strip at equal distance and large enough to take a1/4inch brass screw, No. 0 size. Temporarily screw the tube in position, and from a piece of thin brass make a plate for the inside. An oval hole will have to be made in the plate to enable it to seat flat over the tube. Solder this while in position. Then remove the whole, and replace, after white-leading where wood touches brass.The deck-beams, three in number and1/4inch square in section, must now be fitted. The sheer edge which we left3/8inch wide must be recessed to receive the beams, the recess being made with a1/4-inch chisel.Before gluing beams in, three coats of good varnish must be applied to the inside of shell.The deck should now be prepared and fitted. You will require a piece of pine of ample length and breadth,1/8inch in thickness, and after planing finely and sand-papering, pieces of the same stuff should be glued on the under face to reinforce it where the bowsprit, keel-plate, hatch rim, and mast will be fitted. Cut these pieces to shape before gluing on.Before doing the latter, apply a coat of clear size to the upper face of the deck; this will bring up the grain, so paper it down when dry. This process should be repeated three times.Three coats of varnish should be given to the under side of the deck after the pieces have been glued on, and when dry the deck can be fitted,3/8-inch veneer pins being used for fixing on, and care being taken to get it true to position. A center line is drawn down the under side of the deck, and marks made to correspond at the stern and transom on the shell.The planking lines on the deck can be drawn to suit your fancy, India ink and a draftsman's ruling pen being used to do it, afterward applying two coats of carriage varnish.To paint the hull, white lead and dryers, in the proportion of 5 to 1 by weight respectively, should be dissolved in turpentine, a few drops of linseed oil being mixed to make it work freely. Have thisabout the consistency of milk, and, after straining, give the hull about eight coats, one every twenty-four hours, rubbing each down when dry with No. 00 sandpaper. Keep the joint representing the load water-line always in sight by penciling over after each coat of paint is dry. When a sufficient body of paint has been applied, the colors can be applied. Enamel is best for this. Stick strips of gummed paper around the hull at the water-line, and paint up to the edge. When the paint is dry the paper can be soaked off, the paper being again applied, but reversed for the other color. If you can use a lining brush the paper is not necessary for the second color.While the painting is going on, spars, sails, and fittings can be made. As the spars have to be varnished, it is best to make them first. Pine should be used, and after cutting strips of suitable length and diameter, plane them square in section. With the batten draw on the face the amount of taper to be given, and plane down to this line, still keeping the spar square in section. This having been done, the corners are planed off carefully until the spar is octagonal in section, when it is easy to make it perfectly round with sandpaper by rubbing with the paper rolled around the stick. The diameter of our mast is1/2inch parallel until the hoist of the fore triangle is reached, tapering from there to1/4inch at the masthead or truck. The boom is1/4inch at the gooseneck, thickening to3/8inch wherethe main-sheet is attached, down to1/4inch at the outboard end. The jib-boom is slightly less than1/4inch parallel.All spars should be treated with clear size and fine sandpaper before varnishing. This will prevent discoloring by the latter, and will also allow the India ink markings to be made, which latter will be a guide for the trimming of the sails.In order that any yacht, model or otherwise, may be able to perform her best, it is essential that she should have well setting sails. In fact, in a model a badly setting sail will sometimes even be enough to prevent her going to windward at all. By well setting sails we mean sails that are naturally flat and not made so by straining them out on the spars. Light material, such as cambric or light union silk, is best for this purpose, but not a material that has any dressing in it.This particular sail plan is very easy to mark out. Lay your material out on a table or smooth surface and pin it down with drawing-pins, sufficiently stretching it so as to pull out any creases. The length of the back edge of the mainsail (which is called the leech) is measured off 11/4inches inside the edge of the cloth, and a curve struck as illustrated. The other two sides of the mainsail are then laid off and pencil lines drawn. You will note that allowance must be made for hemming the back edge of the mainsail. If your sewing-machine has a hemmer, find out how wide a hem it makes (thesmaller the better), and make allowance accordingly, twice the width of the hem being necessary. Much depends upon the tension at which the machine is set, so be careful that the latter is sufficiently slack so that it does not draw up the material.The jib is marked out in the same manner, and, as illustrated, the lines representing the positions of the batten sleeves are drawn. The batten sleeves are small pockets into which thin pieces of cane (called battens) are inserted to help the sail to set nicely. Unless the sail is a good cut to begin with, however, the insertion of these battens will never make it right. The sails should now be cut out with a sharp penknife or scissors, care being taken not to pull the cloth, and especially not along the edges that run across the threads. You then hem the backs and also the foot of the jib. The batten sleeves (which should be of white satin ribbon about3/8inch in width) should now be sewn on by stitching down along the extreme edge to the line drawn, and then down the other edge, the ends being left open. A strip of narrow tape is sewn across the foot of the jib-sail to take the strain of the pull, the part of the jib contained by the curve of the foot and the tape being known as the bonnet of the jib.To prevent the edges of the sails (other than those hemmed) being stretched, you bind them with good tape. The tape is first folded and creased byrubbing over an edge. The end of the tape is then turned in. Take a corner of the sail and place it inside the fold of the tape, care being taken to get the raw edge right up against the crease. The needle of the machine should then be lowered through it as near to the edge of the tape as practicable, taking care that it goes through both edges. Keeping a slight pull on the binding, arrange the cloth in it without pulling the edge. Put the foot of the machine down and sew it, afterward raising the foot again and proceeding as before right around the raw edges of the sail, leaving the needle down each time the foot is raised. Do not sew where a batten sleeve passes under the binding, as you will require the former left open to allow the batten to pass into the fold of the binding. The rings for putting up the luffs of the jib- and main-sail are made by winding a piece of thin brass or German silver wire around a steel rod (the spokes used in the keel being suitable for the latter) and sawing down to divide them. A small eyelet should be put in each corner of the sails, and others spaced evenly at about 21/2inches apart along the boom and about 5 inches apart along the mast, for lacing on. An extra row of stitching may be run down the outer edge of the binding to smooth it down.The simpler the fittings of a model that is required for practical sailing, the better. They should be as light as practical. Aluminum is not advisablefor fittings when the boat is to be sailed in salt water.
You will start by gluing layerCto layerD, blocks being placed between the surface of the layers and the clamps to prevent bruising the wood. These two are then glued to layerB, and when this is thoroughly set they are glued to the layerA. The best glue to use for this job is marine glue, which does not dry too quickly, and so gives plenty of time to see that the layers have not shifted. In every case one clamp should be placed at each extreme end of the shorter layer, so as to insure the ends making contact, the other two being placed equidistant.
While waiting for the glue to set, you can be preparing the four layers (shown belowD) for the lead keel pattern. The lines must be cut out, in this case, with a chisel, as it will be noticed that thelower faces must be left wide enough to receive the top face of the layer beneath it.
It will be noticed that the under face of each of these layers extends beyond the top face aft, and allowance must be made for this. On laying off the lines on the fin layers, do not join up with a point each end, but leave about1/8inch thickness, as shown on the drawing.
These layers must be drilled through to take the keel-bolts, which are made from two motorcycle spokes, twelve-gage. These should be cut to a length of 51/2or 6 inches. Great care should be taken to insure that the midship lines are exactly vertical over each other when these layers are glued up.
Before gluing these four layers on to the hull proper, they should be held in position by means of the spokes, in which position they can be sawed to shape for the keel pattern. First, with a small plane or sharp chisel cut down roughly, then a rasp and different grades of sandpaper are used, working across the joints.
It will be realized that, if the pattern for the keel were cut off dead on the line indicated on the design, there would be a loss of wood through the saw cut. In order to obviate this, another line3/16inch below the proper lead line is drawn, and the saw cut made between these two lines. You will now plane down each face that is left rough by the saw, straight and square to each of these lines.On the top face of the pattern for the lead, glue or tack a piece3/16inch thick along the face, and cut down the edges flush.
You will by this means have made up for the amount of wood carried away by the saw. You will no doubt find a difficulty in holding the pieces of wood for planing in the ordinary way, but it is simple enough if you set the plane nicely, grip it in a vise or bench screw upside down, and push the work over the plane's face, instead of vice versa. But be careful of your fingers!
Take the pieces left from the spokes when cutting down to length, and put these in the holes in the keel pattern. These are for cores, and if you take your pattern to a foundry they will cast it for a small amount, with the holes in it.
Shoot the top face of the lead in the manner before described, and fit on. The hull is now ready for carving out. Screw on your bench two pieces of wood about 18 inches in length and 4 inches wide, so that they project over the edge of the bench about 10 inches. These should be about 15 inches apart. Place your hull upside down on them, and fix it by nailing upward into the top layer. After cutting off the corners of the layers roughly with a chisel you use a small plane set fairly fine, and work all over the hull evenly, taking care not to cut below any of the joints. A small gouge will be required to clear the wood from the region of the after fin, a round rasp—sandpaper beingwrapped around a small stick—being used for smoothing down afterward.
Templates of the cross-sections should now be made from thick white paper. This is done by pricking through the design to transfer their shape onto the paper. The cross-sections have on this account been produced here actual size. If cross-lines representing the water-lines are drawn, you will have an excellent guide for fitting, as these lines will, of course, come opposite each glued joint.
Try your templates now and again as you work, and do not try to finish one spot, but keep the whole at an even stage, and you will see the hull gradually grow into shape.
The topsides (which is the name given to that part of the vessel's hull above the water-line) are responsible for the boat's appearance when afloat, and until the top sheer is cut off the boat looks very disappointing. The cross-lines being still on the upper layer, draw square lines from them down the topsides and from the drawing mark the points through which the sheer-line runs. The thickness of the deck must be allowed for, and as this will be just over1/16inch, the line must be drawn this much below the finished sheer-line. The arch of the transom must be marked, and the hull cut down to the sheer. To avoid the risk of splitting, a number of fine saw cuts are made down each section line and two or three at the transom.
You now proceed to carve out the inside. Padyour bench bearers and rest your hull upon them. A curved wood gouge with a fairly flat edge is the best tool. Get it nicely sharpened, and work all over the inside of hull until it is about3/16inch thick, the top edge being left3/8inch wide.
Keep holding up to the light until it is showing a blood-red color, and smooth down the gouge marks with coarse sandpaper.
The hole for the stern-tube must now be drilled, and the tube made and fitted. The hole should be1/4inch in diameter. First drill a smaller hole, and then with a1/4-inch rat-tail file slowly open it out, at the same time rubbing a groove down the stern-post. The stern-tube is made from a piece of light-gage brass tube, it being cut away with a piercing saw to leave a strip the length of the stern-post. Drill three holes in the strip at equal distance and large enough to take a1/4inch brass screw, No. 0 size. Temporarily screw the tube in position, and from a piece of thin brass make a plate for the inside. An oval hole will have to be made in the plate to enable it to seat flat over the tube. Solder this while in position. Then remove the whole, and replace, after white-leading where wood touches brass.
The deck-beams, three in number and1/4inch square in section, must now be fitted. The sheer edge which we left3/8inch wide must be recessed to receive the beams, the recess being made with a1/4-inch chisel.
Before gluing beams in, three coats of good varnish must be applied to the inside of shell.
The deck should now be prepared and fitted. You will require a piece of pine of ample length and breadth,1/8inch in thickness, and after planing finely and sand-papering, pieces of the same stuff should be glued on the under face to reinforce it where the bowsprit, keel-plate, hatch rim, and mast will be fitted. Cut these pieces to shape before gluing on.
Before doing the latter, apply a coat of clear size to the upper face of the deck; this will bring up the grain, so paper it down when dry. This process should be repeated three times.
Three coats of varnish should be given to the under side of the deck after the pieces have been glued on, and when dry the deck can be fitted,3/8-inch veneer pins being used for fixing on, and care being taken to get it true to position. A center line is drawn down the under side of the deck, and marks made to correspond at the stern and transom on the shell.
The planking lines on the deck can be drawn to suit your fancy, India ink and a draftsman's ruling pen being used to do it, afterward applying two coats of carriage varnish.
To paint the hull, white lead and dryers, in the proportion of 5 to 1 by weight respectively, should be dissolved in turpentine, a few drops of linseed oil being mixed to make it work freely. Have thisabout the consistency of milk, and, after straining, give the hull about eight coats, one every twenty-four hours, rubbing each down when dry with No. 00 sandpaper. Keep the joint representing the load water-line always in sight by penciling over after each coat of paint is dry. When a sufficient body of paint has been applied, the colors can be applied. Enamel is best for this. Stick strips of gummed paper around the hull at the water-line, and paint up to the edge. When the paint is dry the paper can be soaked off, the paper being again applied, but reversed for the other color. If you can use a lining brush the paper is not necessary for the second color.
While the painting is going on, spars, sails, and fittings can be made. As the spars have to be varnished, it is best to make them first. Pine should be used, and after cutting strips of suitable length and diameter, plane them square in section. With the batten draw on the face the amount of taper to be given, and plane down to this line, still keeping the spar square in section. This having been done, the corners are planed off carefully until the spar is octagonal in section, when it is easy to make it perfectly round with sandpaper by rubbing with the paper rolled around the stick. The diameter of our mast is1/2inch parallel until the hoist of the fore triangle is reached, tapering from there to1/4inch at the masthead or truck. The boom is1/4inch at the gooseneck, thickening to3/8inch wherethe main-sheet is attached, down to1/4inch at the outboard end. The jib-boom is slightly less than1/4inch parallel.
All spars should be treated with clear size and fine sandpaper before varnishing. This will prevent discoloring by the latter, and will also allow the India ink markings to be made, which latter will be a guide for the trimming of the sails.
In order that any yacht, model or otherwise, may be able to perform her best, it is essential that she should have well setting sails. In fact, in a model a badly setting sail will sometimes even be enough to prevent her going to windward at all. By well setting sails we mean sails that are naturally flat and not made so by straining them out on the spars. Light material, such as cambric or light union silk, is best for this purpose, but not a material that has any dressing in it.
This particular sail plan is very easy to mark out. Lay your material out on a table or smooth surface and pin it down with drawing-pins, sufficiently stretching it so as to pull out any creases. The length of the back edge of the mainsail (which is called the leech) is measured off 11/4inches inside the edge of the cloth, and a curve struck as illustrated. The other two sides of the mainsail are then laid off and pencil lines drawn. You will note that allowance must be made for hemming the back edge of the mainsail. If your sewing-machine has a hemmer, find out how wide a hem it makes (thesmaller the better), and make allowance accordingly, twice the width of the hem being necessary. Much depends upon the tension at which the machine is set, so be careful that the latter is sufficiently slack so that it does not draw up the material.
The jib is marked out in the same manner, and, as illustrated, the lines representing the positions of the batten sleeves are drawn. The batten sleeves are small pockets into which thin pieces of cane (called battens) are inserted to help the sail to set nicely. Unless the sail is a good cut to begin with, however, the insertion of these battens will never make it right. The sails should now be cut out with a sharp penknife or scissors, care being taken not to pull the cloth, and especially not along the edges that run across the threads. You then hem the backs and also the foot of the jib. The batten sleeves (which should be of white satin ribbon about3/8inch in width) should now be sewn on by stitching down along the extreme edge to the line drawn, and then down the other edge, the ends being left open. A strip of narrow tape is sewn across the foot of the jib-sail to take the strain of the pull, the part of the jib contained by the curve of the foot and the tape being known as the bonnet of the jib.
To prevent the edges of the sails (other than those hemmed) being stretched, you bind them with good tape. The tape is first folded and creased byrubbing over an edge. The end of the tape is then turned in. Take a corner of the sail and place it inside the fold of the tape, care being taken to get the raw edge right up against the crease. The needle of the machine should then be lowered through it as near to the edge of the tape as practicable, taking care that it goes through both edges. Keeping a slight pull on the binding, arrange the cloth in it without pulling the edge. Put the foot of the machine down and sew it, afterward raising the foot again and proceeding as before right around the raw edges of the sail, leaving the needle down each time the foot is raised. Do not sew where a batten sleeve passes under the binding, as you will require the former left open to allow the batten to pass into the fold of the binding. The rings for putting up the luffs of the jib- and main-sail are made by winding a piece of thin brass or German silver wire around a steel rod (the spokes used in the keel being suitable for the latter) and sawing down to divide them. A small eyelet should be put in each corner of the sails, and others spaced evenly at about 21/2inches apart along the boom and about 5 inches apart along the mast, for lacing on. An extra row of stitching may be run down the outer edge of the binding to smooth it down.
The simpler the fittings of a model that is required for practical sailing, the better. They should be as light as practical. Aluminum is not advisablefor fittings when the boat is to be sailed in salt water.