How to make a boat with your hands drawings. DIY wooden boat: instructions for making

A boat is an indispensable means of transport in areas surrounded by water bodies. Also, for any fishing enthusiast, a good boat is an indispensable tool. To make a boat with your own hands, it will take a lot of time and effort, this also applies to the financial side. However, today there are many materials that allow you to quickly and inexpensively build a watercraft, one of which is foam. The information presented below will help you understand that making a foam boat is quite realistic.

Styrofoam is a fairly versatile material for making various DIY projects.

The polymer from which the foam is made has the form of a foamed mass. Due to this, there is a lot of air between its particles, which allows the material not to sink in water. In addition, the foam has good thermal insulation properties, low weight, high buoyancy due to the large area of the material and lightness. Styrofoam is available to everyone at a cost, and is also easily processed by a tool and glues well. But, this material is easily destroyed, so it cannot be bent and given to it. complex shapes. Therefore, in order to give strength homemade boat, its body is not made of solid foam, but of a sandwich sheathing, consisting of a layer of foam with glass mat. Sandwich technology lies in the fact that between the two layers of the material that takes on the main load, there is a separating layer of a lighter material. Thus, two layers of fiberglass are separated by foam.

You can use regular extruded polystyrene without fiberglass, but such a homemade foam boat will require sheathing of plywood or other protective material on the outside, such as film or tarpaulin.

Homemade foam boats: drawings

On the Internet you can find a lot various models and drawings

Before you make a boat out of foam, you need to draw up its project. To do this, it is necessary to draw all the components of the future structure with the exact dimensions and shape. Typically the boat is 2.6m long and 0.78m wide at the bottom. The hardest part of the design is making the hull out of parts that don't flex.

It is recommended to make drawings of the boat in full size in order to avoid errors in the calculations and be able to directly mark the details of the hull. The drawing is applied to plywood, the so-called plaza. On the plaza, the details of the boat are drawn, forming a bookmark, or the frame of the vessel - the keel, transom, knobs, stem, sternpost, indicating the width, height, cross section keel. To save space on the plazas, you can draw side and half-width projections one on top of the other, designating them different colors. The projection of the hull should reflect the branches of the frame of both sides - right and left, which are best combined into bow and stern groups.

In order for the quality of the manufactured vessel to correspond to the project, it is necessary to take into account the rules for the location of theoretical lines: these are surface lines outer skin, inner decking, aft and forward edges of the frames, as well as the edge lines of the carlings and stringers. In more detail, the design of the vessel and the assembly of the drawing can be viewed on the video.

How to make a boat out of foam with your own hands

Foam boat is easy to make

After making a drawing with a detailed drawing of all the elements of the boat, you can begin to assemble the frame. The inner, outer, and main skin will be attached to the skeleton of the boat. It must be durable, because the quality of the craft depends on it. The main skin, made of foam, gives the vessel stability and unsinkability on the water. The elements of the main skin must be tightly glued to each other so as not to let moisture through. The inner skin serves to protect the fragile foam from mechanical damage inside the vessel, and the outer skin - from the outside, it must be waterproof and durable.

Frame manufacturing

An important role is played by the frame of the boat

The skeleton of the boat is made of wooden blocks. This is an important part of the design, and it must be strong, rigid and reliable. It is assembled in parts: each component part is measured, and fastened together with screws or nails. To make the frame even more durable, metal corners and plates can be attached over the screw fasteners. The ribs of the frame are made of plywood. When it is assembled, you can start making skins.

Production of the main cladding

Carefully choose epoxy resins

The main plating will make it possible to make sure that the foam boat does not sink with your own hands, but keeps well on the water. For its manufacture, you need to take foam sheets 5-10 cm thick, epoxy glue, a sharp tool for cutting polystyrene foam, as well as measuring instruments.

Measurements of the area of \u200b\u200bthe frame of the entire boat are applied to the foam sheets. Then they are divided into separate measurements, which will later be collected together. Since the foam cannot be bent, the corner joints are made of three elements. To attach the foam to the frame, you can use epoxy glue, which glues the sheets, as well as nails with wide hats made of flat metal plates.

Fabrication of interior and exterior cladding

The inner skin serves as a protective frame for the main EPS skin. It helps to preserve the integrity of the material from various mechanical influences, including pressure from the weight of a person inside the vessel. For the manufacture of inner lining you can take plywood. First, the area of the inner surface of the vessel is measured. You can sew up the entire area inside the boat completely or just the floor and the lower part of the sides. After taking measurements, they are applied to plywood, after which it is glued in separate parts to the main skin using epoxy glue. It is necessary to ensure that the plywood does not sag under the weight of a person, damaging the polystyrene foam.

The outer skin must be carried out so that the boat does not damage the bottom or sides of the uneven bottom or other obstacles. In addition, it will create a waterproof surface. To create a protective surface, plywood is glued to those places on the vessel where a hole is most likely to occur, as well as the bow of the boat. The rest of the hull can be covered with a tarpaulin for moisture resistance.

Do-it-yourself foam and fiberglass boat

Fiberglass is easy to buy at construction market or order online

Homemade foam, pasted over with fiberglass, is made according to the following scheme:

After the project of the future vessel is made, as described earlier, it is necessary to make a model of the boat from plywood. Pieces of this material are cut out based on the elements of the project, glued together using epoxy-based glue (epoxy resin can also be used).
Around the plywood model, polystyrene sheets pre-prepared according to the drawing are glued together. For better adhesion of the joints, they can be cut at an angle of 45 degrees.
The perimeter of the boat is covered with a frame of slats 10x30 mm in size.
The transom and stem must be attached to the plywood model with screws.
Further, the bottom and polystyrene are cut out, glued to the side and end parts, and the load is placed on top. Excess material at the joints must be cut off.
The boards that were fastened with screws are now glued. They were needed so that the polystyrene foam did not dent during gluing. The places of the holes from the screws are sealed with foam.
The surface of the boat is sanded with sandpaper.
Now you need to use fiberglass to glue the hull at the rate of material for 1 layer for the sides and 2 layers for the bottom.
The body needs to be puttied, then cleaned.
From the inside, the hull is also covered with fiberglass, the sides in 1 layer, and the bottom - with a double layer, then it is puttied and cleaned in the same way as the outer surface of the boat.

A 10x30 mm beam is also attached along the perimeter of the inner side, its fixation is carried out with stainless screws with countersunk heads. A hole is made between the inner and outer fenders, where rectangular bars are inserted from both sides for fastening the sub-keys. Subsequently, a socket made of a metal tube for oarlocks will be welded there. From above, the sides are also pasted over with fiberglass to exclude possible leaks between the bars to the expanded polystyrene. On the bottom, stringers are attached to the screws, covered epoxy resin. The final finishing of the boat made of expanded polystyrene is carried out using an epoxy primer applied in two layers.

Probably every fishing enthusiast at least once thought about how to make a homemade boat. This is not an easy task, but it is still possible to make such a craft.

And it is not necessary to be an engineer, all that is required of you is a few hours of free time. And you will learn about how home-made plywood boats are made from our today's article.

Manufacturing difficulties

Is it really difficult to make such a design in the presence of minimum set tools? As practice shows, even with such equipment, a home-made inflatable boat (or plywood) is easily made in 3-4 hours. Due to the fact that it takes a minimum of time to complete all these works, you can even make a boat in the open air. Well, in the event of a change in the weather, you can always cover it with a tarpaulin or a piece of plastic wrap.

What are good

First, plywood is lightweight, durable and quite warm material. It is almost impossible to kill such a boat, and it does not weigh too much. Secondly, unlike rubber counterparts, the space in a plywood boat is enough for several people (at the same time, inside, between the seats, you can fit all the necessary fishing tackle). In store versions free space catastrophically lacking.

Thirdly, being in a wooden boat, you do not feel discomfort at all.

Preparation of materials

The main material from which homemade boats are made is plywood. There are no difficulties in finding it on the market. Plywood is perhaps the most affordable and cheap material for such work. Yes, and it is very convenient to work with her.

Getting down to business

First of all, I would like to note that any work related to self-manufacturing any means (be it a tractor or something else, it doesn’t matter), must be carried out clearly according to a given scheme. In this case, you should have drawings of homemade boats in your hands. In some cases, drawings can be replaced with a sketch drawing.

So, how it is done To assemble the case, you will need to prepare dry boards 2.5 centimeters thick and a 6-mm plywood sheet. The width of the boards for the stern and sides should be 30.5 centimeters. This is the most optimal dimensions for a fishing boat. All other elements that are inside the structure (seats and struts) are made from boards 2.5 centimeters wide. At the same time, the length of these parts is 86.4 centimeters. It must be borne in mind that the dimensions of all these elements must be exactly maintained, since they are all attached to the boat hull only with self-tapping screws.

The manufacture of all parts and elements of this design does not cause any difficulties and difficulties. This is due to their simple geometric shape.

In the course of work, pay special attention to fitting the mating surfaces and frilling the boat. All joining edges must be carefully fitted and have minimal gaps along the entire length. As fasteners, either tin-plated or galvanized self-tapping screws are used. As for the dimensions of these fasteners, depending on the place of application, they can be as follows:

The bottom of the boat is made of plywood sheet 6 mm thick. But, since this part of the floating facility will be constantly exposed to water, for the watertightness of the boat, additionally treat the joints of the hull and the bottom with glue of the VIAM-B / 3 type and fix it with screws around the entire perimeter. If there is no such tool ("VIAM-B / 3"), it is quite suitable as an alternative Oil paint. Although it does not have good adhesive properties and characteristics, it gives a durable and waterproof coating. It should be noted that the distance between the screws should be about 4 centimeters. External seams should be carefully glued with a cloth or percale using AK-20. In order not to fail the bottom of the boat, a rack grate is installed between the struts (the cross section of the rails is 5x2 centimeters).

The resulting liquid should be diluted with clean drying oil. In this case, the calculation is made so that the boat can be painted another 2-3 times. In terms of its properties, liquid paint is better, it spreads more easily, and therefore gives a more durable and even coating. When applying this product to the boat, wide soft flute brushes are used.

Some enthusiasts use nitro paints based on their high quality finish. However, we do not recommend using them for such boats, as they do not provide the necessary durability to the wood (accordingly, the structure becomes less durable and unusable every year).

Important Points

If home-made motor boats are made, then a drawing is additionally made special fasteners for electric or gasoline engine. However, a simpler and cheaper option would be to use conventional oars. They are often made from a 35mm birch plank. At the same time, a spike with a handle is installed at the end of the spindle, and brass linings are applied to the edge of the blade. Next, the paddle is primed and painted.

And finally, some statistics. As practice shows, the average service life of plywood boats is about 15-20 years. Neither plastic nor even their rubber competitors can boast of such survivability.

A boat on the farm may be needed not only for fishing, hunting or recreation on the water. In sparsely populated regions with a developed network of waterways, a boat is an essential item, and in populated areas, the production and rental of watercraft profitable business. Everyone knows how boaters make money at resorts. However, in trade classifiers, small boats do not belong to goods whose pricing is subject to regulation. Therefore, the question: is this possible at all, and how a boat is made with one's own hands is quite popular. The answer to the first question is unambiguous: yes, and much easier than is commonly believed. A good, roomy, reliable and seaworthy boat can be made far from the water without a boathouse and a slipway, in any room that is suitable in size. And how - there is this article about it.

In preparing materials for this publication, the books “300 Tips on Boats, Boats and Motors” were of great help. G. M. Novak. L. Shipbuilding 1977 and "Kurbatov D. A. 15 projects of ships for amateur construction" L. Shipbuilding 1986. The author expresses his deep gratitude to the authors of these informative guides. Further, in the hints to the illustrations, they are designated “H74”, “H77” and “K.”, respectively. As for the years of publication, have the waters and winds changed since then? Today's ships are built and sail according to the same laws, only modern materials and computer technology allow them to be used more fully.

Organizational questions

The reader probably already has questions: is it really so simple? Built - and swim? With a wife, kids, passengers, at sea in a storm? Depending on the circumstances, you may need a trail for a rigid hull boat. documents and supplies:

A boat for myself only, a small non-navigable body of water - sales receipts for used materials in case you need to prove that they were not stolen. A reservoir is considered small, in which the distance from the coast is possible by no more than 500 m, and a single boat is only for itself;

A boat for oneself, a navigable reservoir of any size - additionally a certificate for the right to drive a small boat (an analogue of the rights to motor vehicles) and a certificate of its registration. Both are issued by the local authorities of the transport (water) inspection. On board the boat must be marked with its registration number in the prescribed form;

The same as according to paragraphs. 1 and 2, there can be free passengers in the boat - except for documents under paragraphs. 1 and 2 also a life jacket for each person on board and a mandatory minimum set of supplies, see below;

All the same, but passengers or cargo are paid - in addition, a license for the right of passenger or cargo transportation by water;

All according to paragraphs. 1-4, sailing or motor-sailing boat, incl. with a complete emergency sail - in addition, a yacht helmsman's certificate or other certificate for the right to control a sailing vessel;

The boat is made for sale, not serial - a license for the right to manufacture small boats.

I must say that in non-navigable water bodies, violations of paragraphs. 1-3 are massive, and in sparsely populated areas - indiscriminate. The Water Inspectorate has neither legal nor organizational and technical capabilities to get there. Therefore, claims against the owner of the vessel arise or his criminal prosecution begins only upon the fact of the consequences of the accident.

What is yes and what is not?

There are countless designs of small boats, but for a novice amateur when choosing a prototype you need to follow the trail. considerations that a homemade boat must satisfy:

The boat must be built according to a proven design and / or with full consideration of the vital provisions of the theory of the ship, the rules of shipbuilding and navigation, see below;

The boat must be reliable, i.e. strong, durable, stable, capacious in terms of weight and volume, sufficiently seaworthy for the given navigation conditions and at the same time controllable in waves, currents in the river and in a shallow overgrown reservoir;

The boat should be light enough so that the owner can single-handedly pull it ashore or launch it, and with an adult physically averagely developed assistant, load it for transportation;

Boat building technology should not include operations requiring special skills or production equipment, but should be forgiving of beginner mistakes and replacing standard materials and manufacturing methods with those available under the circumstances;

It is desirable that the boat could walk well and stay on the wave on oars, under the motor and sail - to save fuel and have a good rest;

The cost of building a boat should be kept to a minimum;

If the boat is stored away from a body of water, it is highly desirable that it meet the requirements for cartop ships, i.e. allowed transportation on the top rack passenger car.

For the whole set of qualities, except for the price of materials, the best choice for his first ship will be a plywood boat. The boardwalk will cost approx. half the price, but it will be as much heavier and will last much less, except for the option with a steel thin-walled bottom, see below. Homemade fiberglass boats are expensive and difficult to build, although they are reliable and durable. Subject to all these conditions, the following are not considered further:

All-metal welded and riveted boats.

Gliding ships.

Small pleasure catamarans.

foam boats, plastic bottles, pontoon boats and planks of rectangular shape, etc. exotic.

Inflatable boat.

The grounds for such "truncation" are as follows. All-metal home-made vessels are not examined and registered by the transport inspection bodies due to the fact that it is technically impossible to ensure their proper reliability in artisanal conditions.

Building a glider is not a job for a beginner. Regular dynamic loads on the planing hull are high, and you can take on it after making sure that your first boat still floats well. Although, it must be said, having some experience, at home it is quite possible to build a boat-kartop that goes on gliding on a small wave under a motor of only 3.5-6 hp, see for example. track. video.

Video: an example of a homemade glider boat and its testing

A small catamaran, let it be known to the reader, is easier to build than a boat of equal capacity, and the restrictions on the choice of materials for it are softer; for example, foam can be widely used. On the bridge of the catamaran (a platform that connects the hulls-floats) you can stand, walk, tumble as you like, you can put up a tent there and even cook a barbecue. However, a catamaran is not a boat and the issue of homemade catamarans requires separate consideration.

Boat exotics from improvised materials are simply dangerous. For example, a monohull foam boat will either be something extremely fragile, suitable for swimming only in a paddock fence, or an almost uncontrollable raft, highly susceptible to drift by currents or winds.

As for inflatable boats, the enthusiasm for them is explained, in addition to the possibility of carrying on oneself, by the fact that in order to register a purchased “gum” boat on a navigable reservoir, it is enough to present a manufacturer’s certificate, and even then the water inspection looks at him through his fingers to the side. However, this does not apply to homemade inflatable boats in any way.

At the same time, it is enough to look at the patterns of the simplest inflatable boat (see fig.) to make sure that it is much more difficult to glue its seams properly in artisanal conditions than to build a more capacious and reliable boat with a rigid hull, and quality materials for soft plastic boat cost much more than best plywood and epoxy glue.

But the most important thing: without special equipment, it is generally impossible to reliably (without the possibility of inspection) to glue bulkheads into a cylinder. A home-made "gum" will be one-balloon: suddenly there is a hole, and you are not in a life jacket, it is far from the shore, or the reservoir is heavily overgrown - you just have to mentally sum up your life. For the end is near.

Note: if you definitely want to glue your boat instead of building it, then it’s better to make it from ... scraps water pipes. You can’t blow off such a boat and hide it in a backpack, but it will be unsinkable. How a boat is made pvc pipes, see the video below.

Video: an example of a homemade PVC pipe boat

What to do?

There are also many designs of plywood and plank boats that do not require production conditions for the construction; People have been swimming since time immemorial. Let's try to decide how a novice shipbuilder-navigator can navigate in this diversity. For example, boats such as canoes (item 1 in the figure), kayaks, kayaks or domestic troubles are very walkable, very seaworthy and at the same time are not afraid of overgrown shallow waters. However, to manage them, not only experience is needed, but a great art. In terms of the number of drownings among beginners, canoe-type boats are firmly in the top of the rating among small boats. In addition, such rigid-hulled boats are technologically complex, because their contours are of double curvature.

The Russian fofan boat (pos. 2) is no less legendary in its reliability than the American dory (see below), but it is very stable, roomy, and a green salaga can manage it. Twisted contours in the bow make the fofan well suited to the wave in full load, and together with the “pot-bellied” hull, gentle contours in the stern and a deepened transom, it is able to go quite quickly, up to 20 km / h or more, under a sufficiently powerful motor in a transitional (semi-planing ) mode. But, as we can see, the contours of the fofan are also doubly curved, and it is heavy: to turn the fofan, you need at least 2-3 strong men.

The pleasure and fishing boat Russian dinghy (pos. 3; Russian because there is also an American dinghy dinghy boat, see below) is light, but again with double curvature contours. The same applies to the marine sailboat, pos. 5, although under sail she keeps steadily on course on a 4-point wave, and it is possible to pull her ashore alone.

Blow once!

So, we decided on one more requirement in a home-made plywood boat: its contours must be of single curvature, i.e. the surfaces forming the body must be curved planes. For small quiet inland waters, the best choice would be a skiff-type punt boat, pos. 5. The Scythians in such conditions proved to be the most reliable courts. In addition, skiff boats are cheap, easy to build, light: a 4-meter skiff with a galvanized bottom can be lifted and loaded by one person. An additional advantage for these sailing conditions is that the Scythians are perfectly controlled in the course and in overgrown reservoirs. There is simply nothing for water or algae to grab onto.

Note: contrary to popular belief, a skiff boat can sail perfectly, see below. But - only on calm water! On a wave, the Scythian, like any shallow-draft punt, becomes dangerous - the wave hits the bottom, knocking the ship off course and trying to capsize.

In somewhat more difficult sailing conditions, on waves up to 2-3 points, a dinghy boat will be optimal. In appearance, the dinghy is easy to recognize by the bow transom-forespiegel and the keeled (as they say, having a transverse V) bottom, pos. 6. The latter makes it easier for the dinghy to climb the wave, and the forespille makes the ratio of capacity to overall dimensions and the dinghy's own weight is almost a record. Thanks to this, the dinghy is the most popular weekend boat among residents of places far from the water: a 2-3-seater dinghy on the top trunk fits into the dimensions of a car, and can weigh less than 50 kg. Technologically, the dinghy is even simpler than the skiff - it can be assembled by sewing plywood (see below) just on the floor in the apartment.

Dinghy under sail (pos. 7) is quite safe, but very nimble, and therefore an excellent vessel for initial sailing training. I learned how to manage this - you can safely move on to the tiller / steering wheel and sheets of a large yacht. In the USSR, the Golden Fish dinghy was widely used to train teenage cadets in yacht clubs.

Note: in coastal areas, one can often meet nautical pointed-nosed dinghs. Outwardly, they look like a fofan squeezed along (pos. 8), but in fact the hydrodynamics and mechanics of their body are almost the same as those of a dinghy with a forespiegel.

Finally, if you live by the sea or a large inland lake, know the big water and longed to finally build a boat for it with your own hands, then the choice should be stopped on the dory. Dory boats are truly ocean-going. Newfoundland fishermen have caught and are catching fish 280 and even 400 km from the coast. The seaworthiness and reliability of dories are phenomenal: there are many cases when large reliable ships were wrecked in a severe storm, and dories then returned home safely in the same waters.

Dory boats are known in 2 modifications: purely rowing banking and sailing (pos. 9). To manage a bank dory, you need to be a salty sailor from childhood, because. their static stability is low. The sailing dory is not so capricious; a beginner who knows the basics of sailing a ship is able to learn how to manage it. In addition, it is possible to install a motor in a well on a sailing dory. Of course, equipping a boat with a motor well is more difficult than strengthening a transom for a motor (see below), but on the other hand, the motor and propeller will be better protected from damage, and it will be possible to repair the motor on the water without fear of drowning a part or tool.

ABC truths

To make a boat right, you need to choose a technically competent, suitable for the given sailing conditions and available resources for its project. To choose a project, you need to know at least the very basics of ship theory, small shipbuilding, navigation and maritime practice on small ships. So let's start with theory.

Propulsion

The propulsion of a displacement vessel is determined by the Froude number Fr. Physically, it means that with an increase in Fr, the length of the bow wave of the vessel increases rapidly, see Fig.:

At the same time, most of the engine power or sail thrust is spent on maintaining it. The motor switches to the “fuel-burning” mode, at the same time quickly burning its resource, and the sail, as a rule, is not able to pull the vessel up to Fr>0.3. Hence the important conclusion: do not try to increase the speed of the boat by putting too powerful a motor on it. You will only make swimming more dangerous and you will burn money for fuel in vain. If the recommended motor power is not indicated in the boat project, it can be determined from the table. on the trail. rice.

Movement at a value of Fr that is too high for a given hull is also dangerous: the boat may seem to be hanging on the crests of neighboring waves, or it will tend to move back from the bow wave and burrow its stern into the water. If, frightened by the wave that has risen in front of the bow, sharply release the gas, the boat will be flooded from the stern with the next wave that has come running: having formed, the waves move according to their own laws.

The consumption of energy driving the vessel for wave formation depends not only on the length, but also on the height of the waves formed. It can be reduced, firstly, by increasing the ratio of the length of the vessel to its width (the “length runs” rule), but at the same time its lateral stability and controllability decrease. Secondly, the rational construction of the hull contours: its drill along the frames (see below) should be as gentle as possible. Thirdly, with sheathing (see pos. 2 and 4 in the figure with types of boats). The ribs of the skin belts turbulize the boundary layer of water, preventing the bow wave from swelling too much. This, by the way, is one of the secrets of the excellent propulsion of the combat boats of the Viking drakkars and augers. Unfortunately, sheathing is technologically complex, prone to water leakage and therefore requires regular inspection and maintenance.

Stability

The stability of the vessel is distinguished between static (in the parking lot) and dynamic on the move. The stability of the ship is determined by the interaction of the overturning moment, the force of which is applied to the center of gravity, and the restoring moment, the force of which is applied to the center of buoyancy C - the geometric center of the submerged part of the ship.

The value of stability is determined by the elevation of the metacenter M above the center of gravity G (see Fig.). A ship with a large excess of M over G will be very stable, but also very rolly, with sharp rolling, i.e. overly persistent. With a continuous increase in the angle of heel Θ, the metacenter first "runs away" upward from the center of gravity, and then moves back. When M is below G, the overturning moment will exceed the restoring moment and the vessel will capsize. Resp. the angle Θ for decked ships is called the sunset angle. The critical list for deckless ships will be the one at which the ship scoops sideways. Then Θ is called the flood angle.

The stability rules are subject to the square-cube law. For small vessels, on the one hand, this is bad, because a small vessel turns out to be less stable than a large one of the same proportions. If a 5-meter boat goes with a critical roll, then a roll of a 20-meter schooner in the same wind will not be dangerous, and a 70-meter barge is almost invisible. When in the old days the captains of sailing ships, trying to get away from the storm, ordered "set the sails as much as the masts can withstand," they knew what they were doing. But, on the other hand, for the same reason, the dynamic stability of a more or less regular small displacement vessel will be greater than the static one. In order for a boat, stable in the parking lot, to capsize on the move, its designer will have to try very hard in the opposite sense.

Controllability

It is wrong to think that the ship turns from the rudder. The vessel turns the oncoming flow of water obliquely on its bow, and the rudder only helps it to substitute itself under it, see fig. on right. True, with all due respect to the author of the original source, an inaccuracy crept in: what is designated as the center of gravity of the CG is actually the projection of the center of rotation of the CG ship onto the main plane (see below). This is also an important conclusion: if the boat is poorly controlled, do not sin on a too small rudder blade. Its optimal area is approx. 3% of the cross-sectional area of the hull amidships, i.e. across the widest part. Check and, if it matches, then either you did something wrong, or the project was chosen unimportant.

The position of the CV is determined by the interaction of the moments of forces applied to the CV and C already horizontally. For a perfectly steerable vessel with no roll, the CG is exactly above C, which is what the designers are aiming for. Hence another important conclusion: do not get carried away with the move with a roll. Romantic, but also dangerous, because the controllability of the vessel is reduced, which exacerbates the risk of capsizing.

Sailing

Yachtsmen sometimes say: a sailing yacht is an airplane, one wing of which is in the air and the other in the water. In general, this is correct. Diagrams explaining the principles of vessel movement under oblique sail, see fig. From there it is clear why you can sail against the wind. The first thing that is important here is that the CPU and CBS are widely spaced vertically, which creates a significant heeling moment. Hence the conclusion: if the project of the boat does not provide for sailing weapons, do not put a "self-propelled gun". In extreme cases, and under perfectly favorable circumstances, an emergency sprint sail can be built from a pair of oars and a cover or clothing. For example, the motor died, it was far from the shore, it was exhausted to row, but the wind was weak and the waves were insignificant.

The interaction of sail thrust and lateral resistance of a properly designed ship also creates a moment that tends to bring it to the wind, i.e. turn your nose directly into the wind. On the one hand, this is good, because if the ship turns out to be uncontrollable, it will take a wave on its bow, which is the least dangerous. But on the other hand, if the CPU moves too far ahead of the CBS, the ship will become difficult to control or even uncontrollable: it will be brought to the wind, no matter how you turn the tiller; It's not far from here to disaster.

The matter is complicated by the fact that when the course changes relative to the wind, both the CP and the CBS shift. If the CPU is behind the CBS, the ship will begin to roll away into the wind (“want” to become a stern to it), which threatens with disaster. Hence the most important conclusion: without proper knowledge of the sea, do not experiment with sails! You run the risk of making an “overkill turn” in a light wind on still water!

In order for a vessel without a large deadrise of the bottom and lines specially designed for sailing to be able to carry sailing weapons, lifting keels are used - centerboards - placed in the centerboard wells, see fig. on right. If the project has a sail, but there are no drawings of the daggerboard - we reject, illiterate. Then, some amateurs try to adapt a flat-bottomed boat for sailing by stuffing false keels and longitudinal redans from boards on the bottom, which are incorrectly called bottom stringers (which are actually parts of a hull set). Technically, this is the same as cutting off the wings of an airplane or trying to adapt them, the tail and the jet engine to the bus.

Contours and drawings

The main dimensions and characteristics of the vessel are given in pos. 1 fig., and in pos. 2 - the main planes of its theoretical drawing. The midship plane is indicated by a special squiggle icon. Pos. 3 shows how a theoretical drawing is constructed. Cross-section by diagonals and construction of fish are used in drawings of sufficiently large vessels, performed on a small scale, to verify the coincidence of lines. On the theoretical drawings of small vessels, instead of fish, they often give drill along the frames, see below.

Already by looking at the theoretical drawing, one can estimate at what Froude numbers a given ship is capable of sailing. For example, a boat in pos. 5 - semi-planing. Next, you need to check the coincidence of the lines of the drawing:

The distances from the DP to the waterlines of the overhead lines on the half-width projection must match the distances from the DP to the lines of the frames on the hull projection, respectively. levels from the OP. Taking into account the scale, because the projection of the hull, necessary for the construction of patterns and frame templates, is most often given on an enlarged scale (see pos. 4).

The distances from the OP to the buttocks must be equal to the distances from the OP to the lines of frames and waterlines on the same secant plane parallel to the DP, also taking into account the scale.

Next, you should evaluate the driving performance of the vessel: using the trapezoid method, the cross-sectional areas of the underwater part are determined along the frames and segments, respectively. lengths are plotted along the vertical axis, see fig. The distance between the segments (on the same scale) is one spacing, i.e. the distance between the sections along the frames. The envelope of the segments, the so-called. combatant along the frames, should form a semi-contour of a certain streamlined body.

The construction of the drill on the frames is similar to the application of the area rule in aviation. But, firstly, in incompressible water, its action affects any speeds, and not transonic ones. Secondly, the ship's hull is only partially submerged in water and therefore excites gravitational waves in motion, and not pressure ones. Therefore, the drill on the frames should not look like a half of a drop, but of an animated body, like an artillery shell. The flatter the drill turns out to be along the frames, the more popular the ship will be, and the wide drill speaks of its good controllability. The “tail” at the back indicates the ability to walk on significant Froude numbers, and the “beak” at the front indicates good germination on the wave, but at the same time a tendency to yaw.

Note: in addition to the frames, according to the theoretical drawing, a true bypass of the inclined transom is built, see Fig.:

materials

Wood and plywood

The basic structural materials for a boat require some pre-treatment. To make a wooden boat last as long as possible, wood materials first you need to abundantly soak with a water-soluble antiseptic (biocide) for wood. Not oil, not in the air it will be!

Plywood, incl. waterproof, impregnated in several steps with intermediate drying to avoid delamination. In the latter, only the glue is waterproof, and the veneer is wood as it is. Further, in order to fix the biocide and reduce the swelling of the wood, the material is impregnated in the same way 2-3 times with a water-polymer emulsion. Unless otherwise specified in the project, the thickness of plywood for the sides of a boat up to 4 m long should be taken from 4 mm, for the bottom from 6 mm and for the transom from 12 mm; boards, depending on the species and quality of the wood, three to four times more. The method of correct gluing of wooden parts and the permissible bending radii of the boards are given in fig. above. They are different from construction!

Sheets of plywood larger than 1550 mm are difficult to find, so they are pre-glued into strips of the desired length with a mustache joint, see fig. It is impossible to learn how to accurately and accurately cut plywood from descriptions, so practice on scraps. One can only advise to plan the mustache with a rough planer, and finish it with a grinder or a flat bar wrapped in sandpaper. Glue the sheets with epoxy glue. The quality of the hook is checked next. way:

Cut a strip approx. 10 cm. This is almost always possible, because curvilinear details will be cut out.

The strip is brought into a ring and pulled together until the plywood bursts.

If the joint is of high quality, the plywood should crack anywhere but it.

Type-setting boat hulls are assembled on red-copper nails (holes need to be drilled under them), galvanized or conical screws. Red-copper nails are bitten and riveted in washers; galvanized bend. Holes are drilled under the screws; their dimensions, methods of working with nails and tables of fasteners, see fig.

Note: Recently, quite a few amateurs have been assembling boats on furniture confirmatory screws, using the same technological methods as when assembling cabinet furniture - cabinets, kitchenettes, etc. So far, these boats are floating, but not for long in order to judge their reliability for a long time.

fiberglass

Fiberglass fabric glued with epoxy glue is widely used in small shipbuilding. But there are a lot of complaints about her: they say, she didn’t swim until the fall - it flowed. The reason is the paraffin that is coated on the fiberglass before it is spun and woven. Paraffin from fiberglass is removed by boiling in water. Do not burn, the fabric will become brittle! The fiberglass is boiled in a clean container for at least half an hour, then the container with the contents is allowed to cool completely, the paraffin crust is removed from the surface of the water, and only then the fiberglass is removed.

Techniques for working with fiberglass on fiberglass and wood are shown in fig. Bonding the parts of a set of extruded polystyrene foam XPS - effective method increase rigidity wooden case, slightly increasing its weight, and assembling a plywood boat by sewing on epoxy glue is technologically simple and gives a completely reliable vessel. Staples are made of copper wire with a diameter of 2-3 mm; the pitch of the pairs of holes for them is 40-60 mm. Looking ahead, the technology for sewing boats from plywood on epoxy is as follows:

Cut out parts without allowance;

The edges are planed to form a wedge-shaped profile joint with a base width of 1.5-2 mm;

If the bottom is keeled, its parts are stapled together, the workpiece is placed on the keel blocks (see below) and the sides are sewn on. The flat bottom is immediately placed on the tragus, the sides are sewn on;

Expose the body along the contours (also see below) and fill the seams with glue from the inside;

After the glue has hardened, the seams are also sealed from the inside with 3 layers of fiberglass (see the figure above). It is not necessary to remove the staples: firstly, the seam with them will be stronger, and secondly, the puttied holes from the staples are a potential source of leakage;

When the last sizing hardens, the transoms (transom) are glued in the same way;

The body is removed from the keel blocks (tragus), the brackets are bitten flush from the outside and the seams are pasted over with 3 layers of fiberglass;

Frames, a centerboard well, cans (seats), a breshtuk (see below), a gunwale, a fender, etc., are glued into the body, which is necessary for the project;

Produce refurbishment and finishing.

How to make a boat

We sew

In the designs of the boats of the Kartop Dings and the Scythians, patterns of their details are often given. In this case, the boat is assembled by sewing (stitching) on keel blocks or tragus, see fig. The dry-sewn case is exposed along the contours using templates-patterns and temporary mounting struts. The seams of the sheet seams, as the most durable, are located closer to the nose, as the most loaded and prone to damage.

We are building

The construction of a sharp-chine boat of a larger capacity than a stitched boat with single curvature contours begins with the manufacture of a stem (see below) and the assembly of frame frames. The frames of sewn boats are often simply cut out of plywood (there are only 2-3 of them), but in this case it is so uneconomical - too much is enough expensive material will go to waste. The frames are assembled on the plaza, i.e. on a flat plane, on which the projections of the theoretical drawing are transferred on a scale of 1: 1. If the contours of the boat are simple, and there is not enough space, only the projection of the hull can be transferred to the plaza. Methods for assembling frame frames, as strength, complexity and weight increase, are given in fig. Grooves for the keel and stringers are selected in advance.

Next, the frame frames are placed on the frame (pos. and on the next figure), set vertically, by contours, the keel bar, stem (see below), fender bar and stringers are attached. After that, the set of the body is reduced with an even bar (pos. b). The purpose of the malkovka, firstly, is to create cuts in the keel beam, along which it will be planed to a given deadrise; secondly, to check whether a section of double curvature has been tucked somewhere, and resp. trim the bottom edges of the floor timbers. Then sheathing is applied, starting from the keel (below in the figure). After that, the body is removed from the frame, completed and equipped.

Note: some amateurs, after malkovka, hack against the rules of shipbuilding, removing the cutting of the skin from the muted set onto sheets of packaging cardboard. Then you don’t need to suffer with geometry according to a theoretical drawing, but the boats are nothing, they float.

Nose

The forteven is the most loaded and responsible part of the hull set. One of the immutable rules of navigational safety says: if the danger cannot be avoided, it must be taken on the bow. Therefore, the manufacture of the stem of the boat should be taken with all responsibility.

Boat stem designs are given in fig. Waterstop plugs made of hard, non-rotting wood prevent water from seeping into the hull. In terms of reliability, all these designs are approximately the same. A stem with a false nose is used in boats with a narrow stem.

In waves and when hitting obstacles, the stem experiences large dynamic loads, tending to spread the body, so it is reinforced with an insert-breshtuk. Amateur shipbuilders often neglect it or do not know at all what it is; this is one of the significant reasons that home-made boats serve much less than the terms stated in the projects.

Stern

Another rather important part of the set, especially for a boat designed for a motor, is the transom. Transom design for motor up to 10-12 hp given in fig. on right. Total, with reinforcement, transom thickness - from 40 mm. Possibly more: some outboard motor mounting clamps do not converge less than 50-60mm.

Unsinkability

A radical means of avoiding the dire consequences of accidents on the water is an unsinkable boat. It is quite simple to make a deckless vessel with a displacement of up to 0.5 tons unsinkable: foam blocks are glued under the banks and along the sides from the inside; then, in the bow and in the stern, you can fence off respectively. fore peak and after peak and fill them with foam. The volume of unsinkable blocks in a cube. m is calculated by the formula V=1.2W(1+ρ), where W is the displacement in tons, 1 is the density fresh water, ρ is the mass density of the foam. For example, if ρ=0.08 tf/cub. m, then for a boat with a displacement of 0.25 tons, 0.324 cubic meters will be needed. m or 324 cubic meters. dm foam. It seems to be a lot, but in a dinghy boat 3 m long, such an amount is placed without a noticeable deterioration in habitability.

Supply

The minimum set of mandatory equipment for a recreational and fishing boat consists of oars, life jackets according to human capacity, an anchor on a chain or cable, a mooring end and, in case of navigation in the dark, a white bow or top (on the mast) navigation light all-round visibility. The latter is often neglected, which is inexcusable in our time: there are now on sale autonomous LED lamps the size of a baby's fist with a built-in solar battery and battery. Anchor deserves special attention from this set.

Anchor

Joseph Conrad called the anchors "honest pieces of iron", and no wonder: the anchor may be the last chance to save the ship and the people on it. Small vessels are most often equipped with cat anchors, but this is far from the best option. First, cats often get stuck on rocks. There are cat anchors on sale with paws that lean back with a sharp jerk, but they are unreliable: the vessel can spontaneously anchor just when you need to hold on tightly. Secondly, the cat, like the classic Admiralty anchor, becomes dangerous in shallow water: the vessel can sit down on the bottom of the anchor leg sticking up.

For small vessels, Hall, Matrosov and lightweight Trident anchors of increased holding power are also produced. They are quite expensive, but you can’t make them yourself, you need cast parts. You can make Kurbatov’s welded anchor on your own (see fig.), it is suitable for boats up to 5 m long. pig in 2-3 kg.

Suddenly, Kurbatov's anchor gets stuck in the stones, the ingot must be raised before it is released. The anchor, stuck completely, is released by a strong sharp jerk on the cable. In this case, parts 4 and 8 may be damaged, but in most cases they can be corrected right there with a hammer and pliers.

About anchoring

In the butt of the anchor, it is necessary to thread an eye during manufacture - a steel ring freely dangling in it. An eyelet is also supplied with a gum-tack - the attachment point of the anchor cable / chain to the ship's hull. Eyelets greatly reduce the wear of the cable / chain and the likelihood of their sudden break.

Zhvaka-tack is attached outside to the stem. You need to fasten the gum-tack lower, above the waterline itself. In this case, the boat at anchor will be better to play on the wave, not to burrow its nose into the water on waves, and the likelihood of the anchor getting stuck is much reduced.

Project examples

There are enough good projects of cart boats, dinghys and Scythians in RuNet and in general on the Internet. Therefore, we will dwell on the projects of boats more spacious.

Scythian

The appearance, data and design of the Scythian boat developed by D. A. Kurbatov, suitable for transportation on the upper trunk of a car, are given in fig. Her distinguishing feature extreme cheapness: the main material is boards, and on the bottom there is a small size, i.e. monkeys. If you choose the right boards for the bottom (highlighted in red in the next figure), then the plank bottom will be quite reliable. Moreover, nowadays the seams between the boards can be caulked with a construction deformation cord (used to seal cracks in concrete) and silicone sealant. Of course, the bottom of this boat can also be made of plywood, then its weight will decrease to 70-80 kg.

On the trail. rice. drawings of the details of this boat are given and a method of assembling it is shown, also very economical: on a simplified slipway according to templates. Under the motor, the transom is reinforced, as described above.

Further on fig. the sailing armament of this boat and drawings of oars for it are shown. The sail is rake (emphasis on “o”), you can learn how to handle it in half an hour or an hour, without knowing the theory at all. But - do not put this sail into the wind fresh and stronger! The CPU of a rake sail is significantly higher, it rolls the boat more, and it is a punt!

As for the oars, it is better to make them exactly according to the drawing. Scythian boats do not oar very easily, therefore, in order to save the rower's muscular efforts, the configuration of the oars and the profile of their blades are of great importance.

About iron bottom

Scythian boats are sometimes made with a galvanized iron bottom. Such a boat, firstly, with plywood sides, weighs only approx. 50 kg or less, i.e. it can be turned as you like alone. Secondly, a boat with a steel bottom turns out to be much more durable in reservoirs with an acidic reaction of water, which are more than enough in the Russian Federation: ions of even very weak acids spoil the glue and protective coatings. There is only one minus for home-made boats with a steel bottom: it is useless to present them for examination for the purpose of registration, and they will not look.

Dory

The same author also developed a project for a plywood dory sailing boat, see fig; according to the table of plasma ordinates, the skin is cut, but see above. In shallow sea waters with a short steep "evil" wave (Azov, the north of the Caspian Sea, the Marquis puddle in the Baltic), this boat proved to be better than a sea boat or an Azov longboat.

Below in fig. a structural drawing of the boat is given, the method of its construction on the slipway, the design of the stem and the method of inserting the longitudinal parts of the set are shown. Wood must be of high quality, without knots and defects, because. wooden details sets are prestressed during assembly.

On the trail. Fig. drawings of the sailing armament of the dory are given. Since the dory can sail in fairly strong winds, it is planned to take one reef on the sail. Follow the indicated dimensions exactly: dory boats are very critical to the relative position of the CPU and CLS!

The punts of our rivers

Once upon a time, the shores of lakes and ponds were completely strewn with wooden boats of various sizes and designs. Of course, there were rubber ones, but there were few of them and they served as patched and patched for many years. It was even rarer to find duralumin products produced at that time in small batches.

The punts of our rivers

Those times have sunk into oblivion, and with them the good old traditions of building simple boats by the hunters and fishermen themselves. Now inflatable boats have firmly taken their place. They turned out to be more mobile, light and comfortable.

True, in some places, remote from large settlements, you can still see hand-made ones. That's what I've been using for many years.

The boat, equipped with one loose oar, with a sharp wedge-shaped bow, strong wooden sides, is excellent for moving along narrow rivers and dense reeds, which allows it to be successfully used for fishing and hunting.

Such boats were generally built according to a single principle, but in different parts they had whole line features. For example, some had a wooden bottom, others had a rubber bottom, and others had a tin bottom.

If for some reason you need just one, then you can make it yourself at home. There is nothing complicated in its manufacture, however, the first time it may turn out not quite what you would like.

Material preparation

So, let's begin. Before construction begins, you need to take care of its most important parts - the sides. For this, long, wide, not thick, preferably without knots, pine or spruce boards are selected. They must lie for at least one year in a dry place, on a flat surface with a slight oppression from above in order to avoid their curvature.

We inspect the prepared boards again for defects - cracks, falling knots, etc. Then we measure the desired length (here, and also below, the specific dimensions of the parts of the boat will not be given, because all this is at your discretion) with a small margin and file each of them at an angle of 45 degrees - this will be the bow.

Next, they need to be planed, and the chamfered ends must be chamfered so that the boards pressed against each other in the bow do not have a gap.
We impregnate these areas, and in the future all the others that will be inaccessible for painting after the assembly of the structure. protective layer antiseptic.

After that, we proceed to the manufacture of the base of the nose - a triangular bar. Its length should exceed approximately 1.5 times the width of the sides of the boat. The bar is also planed and covered with a protective layer.

Do not forget to leave a margin at the top and bottom, then after assembly, all the excess will be cut off.

The initial stage of the assembly

Having prepared these elements, we proceed directly to the assembly. We start from the bow, we firmly connect both sides and the triangular bar with self-tapping screws or nails.

We cut the protruding parts from above and below flush with the sides.

It must be exactly the same height as shown in the photo, otherwise the boards may burst during bending. The angle of the strut should also not be made too large.

Having installed the spacer, we begin to bend the sides, here you need a couple of assistants or a rope. Having bent to the required distance, we apply the “back” and determine where and how much the chamfer needs to be chamfered so that the sides adjoin it without gaps.

So, gradually removing, we adjust it until we achieve the desired result.

Having achieved it, we nail the sides and cut off the protruding parts from below, and from above as you wish. I made it as a triangle.

Then we proceed to the installation of permanent struts and seats. Their number and location is up to you. When fixing them (yes, in general, and in other places), be sure to first make a hole with a small drill in order to avoid cracks.

We complete a very important initial stage by chamfering the lower part of the sides, spacers and applying a protective coating on them.

See the continuation of construction in the next part -.

Captain Vrungel believed that whatever you call the ship, it will float. We will not argue with the old, tested sea wolf, but still we will put forward our opinion - how much more carefully and accurately you prepare the drawings of a plywood boat with your own hands, so it will serve you for many years and in any weather. It is the drawings of the vessel that will determine all your further decisions.

It is they who will introduce you to this world of shipbuilding, in which Anglo-Dutch terminology rules. And to understand the terminology of the structural elements of boats, which means successfully reading the proposed drawing, is fundamentally important.

According to the old axiom, start from the stove

Drawings of a homemade plywood boat must necessarily include strict instructions on how to fasten all elements - this is the key issue of the whole structure

Indeed, terminology, if you are rushing into such a bottomless area as building a boat, is of great and decisive importance. We bring to your attention its basics regarding the design of boats, and which appear everywhere on the drawings.

Terminology

Therefore, learn these terms very carefully, they literally permeate any worthwhile drawing of a boat from any material.

In the side view, we note the following structural elements boats, and it is impossible to say which of them is most important, which is less, all elements are required to be used:

A - frame. You can choose the option of an ordinary punt, without frames, but when it comes to such an aspiration thrown on the Internet as “do-it-yourself plywood boat drawings”, the reliability and strength of the structure comes to the fore, which means frames are mandatory;
Spacing - the distance between two frames. The most important characteristic is the design of any boat;
B - sternpost;
C - stem;
D - timber
E - kilson. A very desirable design element, which, however, is often discarded for boats;
F - fender. You cannot do without this element if you are going to make an add-on in the boat. For open models, the fender is not used.
I - breshtuk. We strongly advise you not to neglect this element, the strength of the entire structure greatly depends on it.
J - book. The knee is also extremely important in ensuring the strength of the boat.
K - stringer. It is also an indispensable element if it approaches the construction very carefully.

The top view introduces a few more important terms:

A - beam;
B - half beam. Goes to full beam if you are not building a superstructure on the boat;
C - karengs;
D - midelweiss.

The view from the forecastle introduces terms that will be of fundamental importance at a more advanced stage of construction, when it becomes necessary to strengthen the hull of the boat and set the sail and keel, while also improving driving performance:

A - sheet piling;
B - keel. Providing a keel weight of 50 percent of the weight of the entire boat, you significantly increase its stability. After all, you never know how the rolling will affect you or future passengers, and a solid supply of sucking sweets and even ginger will do little to prolong the pleasure of being on the water, except to quickly get to the shore;
C - steps. Mandatory if you put up a mast;
D - sheet pile;
E - partners. This is the name of the hole in the superstructure for the passage of the mast. Of course, if you do not have an add-on, then you can forget about partnering for now;
F - velvet. Very responsible sheet piling belt at the level of the waterline, water;
H - sheerstrake. The topmost sheet pile.
G - water level;
I - waterway. This element is already an add-on element.

Plywood

The most common material for the manufacture of boats today, of course, is carbon fiber. But this material is the domain of industry. When it comes to independent creativity, such “folk” material as plywood comes to the fore..

Plywood or in other words, wood-laminated board - construction material created by gluing specially crafted veneer. Usually the number of veneer layers is odd and, in any case, more than 3. To increase the strength of plywood, each subsequent layer of veneer with its wood fibers is perpendicular to the fibers of the previous layer. Frames are the foundation of any floating facility. Drawings of plywood boats that claim to be something more than a punt should have a separate option - the location of the frames

Plywood characteristics

When choosing plywood for building a boat, it is very important to choose the right type of plywood.

According to the arrangement of wood fibers on the outer layers, plywood is distinguished:

Longitudinal, when the fibers are directed along the long side, and,
Transverse - short.

For the construction of a boat, it is better to choose a longitudinal one.
Of course, such an isometric drawing is also possible, but this is the easiest option for the heading “free plywood boat drawings” - there are no frames, and the work is in many ways similar to assembly children's constructor, except that the details are tens of times larger

By purpose, plywood is divided into:

construction,
industrial,
packaging,
furniture, and
structural - this is what we choose for our purposes.

There is also a classification of plywood in relation to the effects of moisture, which is fundamentally important for a boat:

FBA is like that, but you should not choose it, it does not meet stringent requirements for moisture resistance;
FC - this is the designation of plywood that is sufficiently resistant to moisture;
PSF - and so, with increased moisture resistance;
FB - impregnated with bakelite varnish, such plywood is considered the most resistant and can be used even in aggressive environments, which is important in our case, and under water;
BS - this one is already simply impregnated with bakelite glue. Consider that if such plywood was at your disposal, then 50% of the success of the whole business is guaranteed. Such plywood is quite for a long time specifically used in aircraft and shipbuilding. It happily combined all the qualities necessary for the craftsman's boat business - excellent flexibility, the highest strength, complete water tightness, and also resistance to decay and deoxidation;
BV - but let this one not be misleading, it is in many ways similar to BS, but does not have moisture resistance.

Useful advice!
When choosing plywood for building a boat, we advise you to pay attention to laminated plywood.
At the very least, it will be just fine if you use one as a sheet pile or on the outside of the hull if it is a single layer.
This will greatly improve the driving performance of your creation, because water is a medium in which the force of friction plays a significant role.
On the other hand, you shouldn't use laminated plywood inside the boat.
Its slippery surface itself, and even moistened with water, can cause a lot of trouble.

Principal characteristic

When it comes to using plywood for building a boat, the choice of plywood for its quality, determined by the number of knots per square meter of the outer layer, will be fundamental.

There are 5 levels of quality:

E - the so-called elite quality, when there are no knots at all. Needless to say, it is always necessary to strive for the choice of just such plywood;
Well, then, a straightforward classification of quality - I, II, III and IV. In the latter case, the number of knots is not controlled.
I- maximum length knots and warping does not exceed 20 mm;
II - cracks no more than 200 mm, wood inserts are permissible, and glue seepage is permissible only on an area of 2% of the total sheet area;
III - no more than 10 pieces of knots with a diameter of no more than 6 mm. There is even a restriction on the total number of shortcomings - no more than 9;
IV - this is the worst quality with even dropped knots and edge defects under 5 mm.

Operating conditions requirements

Most likely, for the construction of a boat you will choose as the most common. There is also birch plywood, but its use is limited by too high a price.

Another thing is very important here - the quality of the processing of the outer surface of the plywood sheet.

According to this indicator, plywood is distinguished:

NSh - unpolished;
Ш1 - polished on one side;
Ш2 - polished on both sides.

Here, it is fundamental and mandatory to use the sanded side of the plywood on the outer side of the case. It is desirable, for safety reasons, not to use the sanded side on the inside.

Dimensions

The natural characteristic of any sheet of plywood is its size.

The industry, according to standards, produces sheets of the following four sizes:

1525 x 1525 mm;
1220 x 2440 mm;
1500 x 3000 mm;
1525 x 3050 mm.

Your choice will largely depend on the size of the boat.

Useful advice!
All the given characteristics of plywood must be indicated in the specification of the boat drawings.
In no case do not agree to purchase the proposed boat drawings if they are not accompanied by a detailed explanatory note describing all the nuances of manufacturing, and most importantly, the choice of plywood type.
The drawings must indicate the degree of processing outside parties corps.
In this connection grinding machine will be one of the most sought after in your work.

conclusions

Building a boat is an exciting creative process for people who still like to live, who are not afraid to experiment and have a design streak. (see also) But, on the other hand, you should not reinvent the wheel, be sure to get acquainted with all the photo materials, study the terminology and various design solutions.

Set yourself up for possible reworking of bad decisions. Know how to "talk to yourself" and communicate with experienced craftsmen. Only in this case is the success of the whole enterprise called “do-it-yourself plywood boat building” possible.

In the presented video in this article you will find additional information on this topic.