Chapter II: How to Make the Hull
Before entering upon the subject of this chapter, I will enumerate the tools which will be needed: these are a small axe, saw, plane, 1 in. gouge, ½ in. gouge, a rasp, a bradawl, a screw-driver, a gimlet, a hammer, a pair of small round-nosed pliers, a rat-tail file, a half-round file, a small mallet, and last, though not least, a good pocket knife.
It is best and easiest, at any rate for beginners, to cut out model ships from a solid block, because if not scooped out too thin, alterations can be made on the outside if desirable; if the block, in process of cutting out, should split, rub it with a piece of flannel dipped in linseed oil every time after working on it, the tools cut just as easily, and all liability to split is obviated.
To make a 3 ft. yacht (see lateral view, frontispiece; deck outline, diagram 8, p. 19; and sectional outlines, p. 37), get a block of deal, with as few knots and cracks in it as possible, and well-seasoned; it must be 39 in. long, 13 in. wide, and 8 in. deep; thus--
Divide it into two exact halves, as shown by the dotted line--this centre line must _never be lost_ or _rubbed out till the hull is finished_; choose the best side for the deck or upper side, divide it lengthways into eleven compartments or divisions, and carefully set off on each side the length of each line (as shown in diagram 8, p. 19); thus--
With the axe (mind all the tools are sharp) chop off carefully both sides of the block till it is shaped thus--
With the gouge cut out the run and entrance in the bottom of the piece of wood, beginning a little forward of the middle for the run; and at same time cut away so much of the bottom as will leave ½ in. for the keel, by ⅝ wide. The next diagram shows one side, with entrance and run cut out.
Having cut out the other side to _correspond exactly_, and rounded the sides and bottom with the plane and rasp, taking care all the curved parts are in keeping with the curves of the deck diagram C, saw a slanting piece off the cutwater, about ½ in. at bottom to nothing at top, measure 36 in. from the middle of the cutwater towards the stern, and cut out the piece of keel in the run, so as to leave the counter (projecting of the stern); thus (the dotted lines show where and how to cut)--
The counter must not project more than 3 in., and therefore the ship will be 3 ft. keel, and 3 ft. 3 in. over all. Now smooth and model the ship to your best ability, see the keel _is quite straight_, and the _sternpost perpendicular to the stempost or cutwater_ (_a a_ is the sternpost in above diagram E).
If the vessel is now exactly equal on both sides, and not lob-sided, as sailors call it, you can finish it with the rasp, scrape it with glass, and polish it with sand paper, making the outside look perfectly ship-shape.
The sectional views here shown enable the model ship builder to judge of the correctness of his work; they represent the hull _when finished_, if cut athwart or across into four pieces of equal length, and by holding the vessel in the required position the builder can see if his model present these or nearly these outlines exteriorly; if so, it is right.
It is not at all necessary to adhere exactly to this outline of the midship section (although it governs the outlines of the other two); it may be cut somewhat flatter on the bottom, as indicated by the dotted lines, and this would of course slightly vary the other sectional outlines, but I do not think it should be made more angular, nor do I advise it, as the vessel would lose too much buoyancy.
The next thing is to scoop it out with the gouge and mallet. Leave the sides everywhere ⅜ or ½ in. thick, and be careful not to scoop thinner, or leave the sides thicker in one part than another.
The gouge is the principal tool for this work, but a centrebit, to bore holes all over the inside, is a great assistance, it saves half the hammering; however, when scooped out and the inside smoothed, your vessel should look thus--
Next make the _sheer_ by planing out the gunwale (gunwale _a a_), beginning at nothing forward at the stem, gradually increasing to ½ in. amidships, and again decreasing to nothing at the stern. The diagram G below shows clearly what is meant by the sheer, and how to fashion it: the dotted line is the sheer--
and a vessel looks very stiff and ungraceful without it.
Now give the inside a coat of white paint, and then the deck can be put on. The deck must be made of one piece of deal plank, without splits or knots, ¼ in. thick at the sides, and ⅜ in. in the middle; this gives the deck a slightly rounded appearance, and, besides, greatly strengthens it. Mark the shape of the gunwale on the plank by turning the ship bottom upwards upon it, and marking it round with a pencil; draw a middle line from end to end, and cut it to the required shape as near as possible.
A beam must now be put across the middle of the ship, exactly level with the gunwale on both sides, to support the deck and strengthen the sides of the ship; the beam should be ½ in. square; thus--
Screw the sides of the ship to the ends of the beam; then put on the deck, and screw it to the gunwale all round with ½ in. brass (everything must be brass except the lead keel) screws at about equal distances of 3 in., and two or three screws through the deck into the beam; if this is done in a workmanlike way, and the edge of the deck planed off and smoothed level with the side of the ship, the hull ought to be perfect, and practically water-tight. Mind in putting in the beam to leave place for the hatchway or step of the mast.
The next operation is to put on the keels--false and leaden. The false keel is simply a strip of beech, oak, or mahogany, of the same length as the keel of the ship, ⅝ in. thick, ½ in. deep at one end, and 1 in. at the other; thus--
This must be screwed into the keel of the ship with brass screws of proper length, _i.e._ not to go through the bottom of the ship, about 6 in. apart. This false keel, and the position it occupies, can be easily seen in the drawing of “Diana,” and is marked K; the leaden keel is underneath as there shown, and I will now describe the best way to make it.
20 lbs. of lead will be required for a 3 ft. yacht, as before stated, and the lead can be melted in any old pot, on any ordinary clear kitchen fire. First make an oblong narrow box or mould of any smooth ½ in. boards--_dry_, or the lead will splutter and be full of air-holes--3 ft. long inside, ⅝ in. inside width, 2 in. deep at one end, and 3 in. at the other; this will hold about 20 lbs. of lead, and here follows a drawing of the mould.
Into the bottom of this mould, and sticking upright, as shown in the drawing, must be placed at equal distances six or eight pegs, beginning about 1 in. from the extreme ends of the mould; these pegs must be rather thicker than the screws intended to screw the leaden to the false keel, and will, as no doubt the intelligent reader already perceives, leave holes in the cast leaden keel for the screws to go through, these screws may be long enough to go through the false keel into the ship’s bottom, and the work will be all the stronger and better. Having melted the lead, pour it at once into the mould, and the keel is made; when cool take it out of the mould, trim it, smooth the sides and top and bottom with the plane, and let the shape be something thus--
Screw it on to and through the false keel (if you cannot make holes through the false keel to receive the screws without danger of splitting it, bore them in their proper places with the bradawl, and then burn them out with a red-hot skewer); the thickest end of the keel must be aft or behind, and when screwing it on mind and bore out the top of the holes in the lead, so that the heads of the screws may be quite level with the lead (this operation is called countersinking the screws); the heaviest end of the lead is put aft so as to make the ship well up at the stem and deep at the stern; the reason for this will be given in the chapter on “sailing a model yacht.”
It may, however, be well to add here that the false keel, by holding the leaden keel at a greater distance from the bottom of the ship, greatly increases the _leverage of the leaden keel without increasing the weight_, and gives great hold upon the water, however little water the hull may draw, so that more sail can be carried, and the ship steer better with this arrangement than without it.
Now try how she floats, and if she floats about 3 in. deeper aft than forward, that will do.
Next get a strip of sheet brass about 5 ft. long, ½ in. wide, and ⅛ in. thick; most likely you will have to get this soldered in two or three pieces; it is to make a band to cover the leaden keel at the bottom, ends, and also the stem and sternpost, to keep them from being injured by stones, &c., on striking the shore, &c.; holes must be punched in it at every 3 in. where it covers the lead, and at every inch where it covers the wood of the stem and sternpost.
The above drawing shows what is meant, and the place it occupies (I have distorted the drawing to show it better); it must be screwed with brass ½ in. screws, countersunk, to the lead keel, &c., as above stated; the cutwater part of it must be filed away to ¼ in. wide, the rest may be left ½ in. wide. This has always been to me the most difficult operation, and it must be well done and put on perfectly straight at bottom and both ends.
When screwing it on leave one hole without screw in the stem for the bobstay, and two in the sternpost for the self-acting rudder, as shown in this drawing.
The one in the stem must be about 5 in. from top, and the two in the sternpost about 5 in. apart--the black dots show the places.
The hull is now finished; next scratch the deck with straight lines ½ in. apart from stem to stern to imitate planks, leaving ½ in. margin all round to look like a gunwale, and with the following remarks I will close this chapter.
It must be understood that it is almost impossible to mention every operation; many things, and the way to do them, must be left to the ingenuity and skill of the builder; it is sufficient that if my directions have been reasonably carried out, the result, so far, will be a good seaworthy model yacht’s hull.
I have given in this chapter and elsewhere the dimensions for a 3 ft. boat, because it is easier to work downwards from a large size than upwards from a small one. There is less chance of mistake, for an error in a 2 ft. boat would be multiplied by working upwards, while the same error would be decreased in working downwards.
A 3 ft. boat is somewhat large and heavy; 2 ft. and 2 ft. 6 in. are the best sizes. Indeed, unless a large boat is specially required, beginners should not attempt anything larger than a 2 ft. boat, and even a boat 1 ft. 6 in. is a very good size for boys, and will sail, &c., as well as a 3 ft. boat, though of course not so fast.
I append tables of measurement for the blocks of wood and weight of keels for all these sizes:--
For boat block (inches) keel (lbs)
3 ft. 39 × 13 × 8 20
2 ft. 6 in. 32½ × 10⅚ × 6⅔ 10
2 ft. 26 × 8⅔ × 5⅓ 7
1 ft. 6 in. 19½ × 6½ × 4 3
It would not matter if in the large sizes the keel were a pound or so heavier, and in the small a half-pound or so; but on no account must they be lighter in any case. I also add the weight of the leaden rudders necessary to make the vessels run before the wind.
3 ft. boat 1¼ lbs.
2 ft. 6 in. boat ¾ ”
2 ft. boat ½ ”
1 ft. 6 in. boat ¼ ”
For the masts, sails, and tackle of smaller boats, the calculation of size may be easily made.
Comments
Log in to leave a comment.
Model yachts and model yacht sailingChapter II: How to Make the Hull
0%9 min left in chapter