Curved plywood. How to bend plywood at home: step-by-step instructions

In construction, as well as apartment renovation, plywood is used only for the manufacture of floors and formwork reusable- at least that’s what happens in most cases. It's no secret that there are exceptions to any rule, and it may happen that it becomes necessary to make complex decorations with radius bends from plywood. In such a situation, you will certainly have to face the question of how to bend plywood? Together with the site, we will look at ways to bend plywood yourself at home.

How to bend plywood photo

How to bend plywood: important points you need to know

The very first thing you need to understand when approaching the question of how to bend plywood is that this material is very stubborn, and in order to twist plywood into a ram’s horn, you will have to work hard. In principle, everything is not as complicated as it might seem at first glance - in some cases this process can even turn out to be quite simple.

That's one thing. In addition to the above, when approaching the question of how to bend plywood at home, you should also know other things. For example, despite its apparent strength, plywood is brittle material, and if you start bending it without preliminary flirting, then it will probably break. Alternatively, on facial layers cracks and delaminations will appear, which will greatly spoil the appearance of what you are doing. Even in factory conditions, the plywood bending process is preceded by preparatory work. In principle, preparation is the methods of bending the material, which we will talk about later.

How to bend plywood with your own hands: various options

By and large, there are not so many options for bending plywood at home - just a couple. The first method is used for small-format blanks (narrow strips up to 30 cm wide), and the second option can be used for large sheets. Let's talk about them in a little more detail.

In both cases, it is advisable to pre-prepare a template - this is, first of all, the accuracy of bending and, secondly, a guarantee that you will not bend the product. Bending plywood back is not a very pleasant and thankless task, fraught with the appearance of cracks and breaks.

Bent plywood: what is it and what is it used for

Another option for making bent plywood is the technology of gluing thin fragments - instead of bending a thick sheet, you bend thin plywood, and then glue them together, achieving the required thickness of the material. This is bent plywood - according to many craftsmen, this is the best option for self-made radial products made from this material. Yes, bending thin sheets is not difficult, but...

In addition, experience in carrying out work of this kind is required. Gluing plywood is not the same as patching a hole in a camera. You need special glue and so on. In general, this technology is not very suitable for one-time work due to the high costs of various devices and templates. Whatever one may say, but the most the best option To solve the question of how to bend plywood 10 mm or more, the method of technological cuts remains - at least it allows you to do without precise templates.

And in conclusion to the topic of how to bend plywood, there is only one thing left to add - or rather, not even to add, but to once again state the fact that this is not a very rewarding task and, most importantly, labor-intensive. There is no reason to mess with him for the sake of one detail. It's another matter if you want to set up mass production, for example, of pioneer drums or arches standard form. They are already in fashion here and not every company involved in their production can offer people affordable prices. Although, having tried to make one similar product, you will understand why its price cannot be cheap.

Every craftsman should know how to bend plywood if he is to sheath curved structures and decorative elements with it. It is necessary to study the basic rules so that the material does not break when bent. The main difficulties lie in the wood structure and individual characteristics slabs

More information about the material

Before bending plywood with your own hands, you need to familiarize yourself with such products in more detail. The product is a wood board obtained by gluing fragments of prepared veneer. To improve the strength properties, the fibers are positioned so that they are perpendicular to each other.

As for the number of layers, it may vary. Most often, sheets consist of an odd number of veneer layers. It is easiest to work with thin slabs, but their scope of application is limited to decorative functions. To construct arches or form volumetric structures of a round type, in any case, thick sheets will be required, which are quite problematic to bend.

The process of soaking elements

Craftsmen who are thinking about how to bend plywood at home without unnecessary difficulties can offer this option. It involves holding the sheets over a tank of boiling water or placing them directly into a liquid medium. Soaking time will depend on the type of product as well as its thickness.

The method of keeping slabs in water is more accessible and safe, so it is proposed to consider it in detail. However, when carrying out work, high-quality plywood must be used. Bad sheets can quickly delaminate. Before starting soaking, it is advisable to lower a small piece of material into a container of water. If nothing happened to it, then you can dip whole fragments.

Step by step actions will look like this:

1. Blank required sizes placed in water for a certain time. You can understand that the product is ready for further transformations by carrying out regular monitoring. The slab will become pliable.
2. Soaking stops when the desired flexibility is achieved. The sheet itself is moved to a convenient place for work.
3. The workpiece is bent and fixed with screws in a certain position until it dries completely.

IN living conditions It is recommended to combine humidification with steaming. With this option, only the outer layer is saturated with water. The bend area is treated with steam. It is best to bend the sheets along the wood fibers, then you will be able to achieve the maximum effect.

Making frequent cuts along the bend

If the question is how to bend thick plywood, then in an effective way there will be the creation of numerous notches in the right place. To create the cuts you will need a cutter. With its help, special stripes are made in a certain area of ​​the wood board.

When working, do not make deep cuts. They should reach a maximum of half the thickness of the sheet. The veneer layer located on the opposite side must not be damaged. Modern boats are often made from slabs rounded using this technology.

So, how to bend plywood by making cuts in it, step by step:

1. Frequent incisions are made in a specific location.
2. The workpiece is given the desired shape by fixing it in the required position.
3. Using PVA or epoxy resin dense veneer is glued.
4. After about 24 hours, the fasteners are removed.

The cuts are best placed on the inside. When gluing veneer over them, voids are formed. If the manufactured structure is used carelessly, cracks may appear.

Method for gluing thin sheets

Before bending a thick sheet of plywood, you should consider using multiple boards. You can glue a number of fragments together, since bending them separately is much easier. However, when using low-quality glue, problems may arise with delamination of the product already at initial stage operation.

First, solid sheets are cut to obtain blanks of suitable sizes. All fragments are bent by hand and fixed to each other using epoxy glue. To avoid deformation changes, clamps must be used.

The final part is wiped off from the dried glue. Possible defects are removed from its surface. On last stage grinding is carried out.

Some nuances

The above information makes it clear how to bend plywood different ways. To achieve the best result, it is advisable to familiarize yourself with some subtleties:

• when soaking, it is allowed to bend the slabs only at elevated temperatures, otherwise cracks may appear;
• elements that will be given a curved shape should be stored in rooms with a stable level of humidity;
• If the purchased material is expensive, you can use the services of specialized companies.

Before bending plywood 10 mm or more, you need to decide on the method to be used. The option should be selected depending on the angle of the break. As for products of smaller thickness, they are bent only by soaking with water or steam.

Humidification timing chart

To determine the number of minutes required to soak the material at temperature conditions 95 degrees along the fibers, you can use the data presented.

Advantages of using bent plywood

The above methods allow you to give wood boards smoothness of forms. In this case, arches, furniture and other decorative elements are aesthetically attractive and mechanically resistant. Curvilinear surfaces make it possible to:

• keep the number of angles to a minimum, thereby significantly reducing the risk of injury;
• give the interior sophistication, because the eyes are more interested in smooth transitions;
• reduce the number of fasteners.

Plywood sheets are indeed excellent material for finishing works and furniture production. The ability to create bends opens up interesting opportunities in the design field. When using bent shapes, stylish products and designs are obtained.

About choosing a method

Knowing how to bend plywood in three main ways, each master must decide on one of them. Each of the options is not universal; it is relevant in a particular situation.

Even the soaking process is not suitable for all cases. It cannot be used to make too strong bends, and it also takes a lot of time, especially if the thickness of the material is quite high.

Is not universal method creating recesses for the flexibility of the sheet. It is not suitable for thin plywood. Typically, a bend is made if the thickness of the slab is at least 2 cm. As for the gluing technology, it can be considered the more universal of all of the above. However, it does not make sense to use it for thin sheets. It’s easier to bend them immediately using the soaking method.

Final part

Some companies manufacture products directly according to customer drawings, so if you wish, you can contact them to avoid unnecessary problems. They produce High Quality with different bending radii.

Few people know that plywood bending is a very common operation in carpentry, even fewer masters are familiar with correct technique execution. We propose to consider the features of this material and its behavior when bending, as well as the basic techniques and devices for bending plywood at home.

Features of plywood behavior when bending

The veneer from which plywood is made is nothing more than a set of elongated fibers. They are rigid and durable, the space between them is filled with a soft binder. To give the sheets additional strength and compensate for warping in plywood layers, veneer has different fiber directions in adjacent layers. Due to this, plywood is a rigid material that is difficult to bend.

Typically, plywood with an even number of veneer layers is used for bending, that is, it does not have a predominant fiber direction. Otherwise, you should calculate the direction of bending across minimum number longitudinal fibers or vice versa - along, if the part is required to have increased strength.

The thinner the plywood, the easier it is to bend. Sheets with three layers bend easily across the grain of the outer layer even when cold

When the fibers are parallel to the fold line, they do not interfere with the curvature of the plane. However, layers located transversely experience significant loads. Typically, the fibers can stretch quite strongly; the conditions necessary for this are provided by their softening due to heating or moistening.

At the same time, layers located on the inner radius of bending experience compressive loads, which are not compensated by the elasticity of the material. If the bend is steep enough, folds may form on its inner side. Sometimes the stress in this area is high enough to cause delamination—rupture of the adhesive layer or even the fibers themselves. This characteristic behavior can be compensated for by a number of technical techniques, which are the subject of this article.

Required tools and equipment

As always, it’s impossible to do without high-quality equipment and tools. Since the basic technology involves softening the sheet, molding it, and then drying it in an immobilized position to take its shape, bending requires at least a set of clamps. Ideally, there should be at least a dozen of them, but you can bend the plywood in stages, rearranging the fasteners.

In this case, along each line across the bend, the workpiece is fixed in three places: at the highest point of the radius and at the edges. In other words, with due diligence you can get by with six clamps, but keep in mind that the accuracy of the dimensions finished part may turn out to be significantly lower than required.

Plywood bending is almost always done using templates. The exception is sheets of arbitrary radius, which are pre-bent before sheathing frame structures. For risers of stairs, chairs, armchairs and other pieces of furniture, the shape of the bent parts is known with high accuracy. Therefore, you first need to make a spatial figure to which the softened sheet will be attached while it dries and takes on the required shape.

There are quite a few types of equipment that provide technologically advanced steaming or soaking of glue. Humidity and temperature must be kept within acceptable limits, otherwise the glue may irreversibly lose its strength properties. At home and for one-time work, you can use calorific heaters or films for heated floors. Wetting is best done not directly, but through a hygroscopic material that can accumulate and gradually release moisture, for example through foam rubber, hemp burlap or felt. It also helps to have all the adjustable tensioning and compression devices available, such as lashing straps or hand jacks.

Bending and soaking

When bending plywood it acts important rule: The higher the thickness of the sheet and the steeper the bending radius, the more effort it will take to soften. If you do not take into account the difference in the quality of plywood, then after soaking you can achieve a bending radius of the order of 50-70 times the sheet thickness. For steeper bends, other methods are recommended.

Soaking or steaming has the goal of softening the fibers in the veneer and making the glue more plastic with the expectation that after drying it will set and reliably fix the new shape of the part. At the same time, oversaturation of wood with water, as well as sudden wetting and drying, is not permissible.

Small sheets of thin plywood are easiest to soften in a steam bath in regular saucepan or in a juicer

For proper soaking, plywood must be kept in conditions of relative humidity of about 90-100% for 2 to 12 hours, depending on the thickness. Periodically you need to check if there is any delamination of the veneer at the ends or swelling in the center. From time to time you can attempt bending. If the part takes shape relatively easily and no cracking is heard, then all that remains is to firmly fix the plywood until it dries completely.

For long parts it is easier to prepare a box from any suitable material and then soften with steam from the steam generator

Wetting is recommended to be carried out when the plywood is laid on flat base and wrapped on each side with a layer hygroscopic material. If the workpiece is not tightly wrapped in film, you should monitor the humidity level and periodically re-spray the burlap with water. Heating to 50-60ºС during wetting helps speed up the process and make the swelling of the glue reversible. It is strictly forbidden to allow plywood to overheat, so you should constantly monitor the temperature.

An alternative to softening by wetting is steaming the plywood. In this case, the sheet is fixed above a container of boiling water or near it. The disadvantage of this method is that the humidity rises throughout the room with concomitant condensation. The advantage of this method is uniform softening and a low risk of overmoistening or overheating.

A vacuum table speeds up the process of softening plywood, as well as subsequent molding according to a template

A softened sheet of plywood is used to cover the pre-prepared frame structure or template, fixed at key points of each bend. The plywood is pressed using clamps or self-tapping screws with a washer sequentially from one edge to the other, and the more often the temporary fastener is installed, and the stiffer it is, the lower the likelihood that the part will change shape after removal from the template.

Machining methods

In some cases, there is no point in resorting to softening: for example, if the part is fixed to a sufficiently rigid frame, it will take on its own over time. the required form due to natural changes in humidity. Another special case is the need to bend plywood to a radius that is less than permissible for a certain thickness. Here it is worth using both softening of the sheet and its mechanical processing.

One of the processing methods before bending is applying to inner side bending a series of cuts parallel to the folding axis. It is better to make cuts with a cone cutter using a linear guide. The depth of the grooves should be no more than 3/4 of the thickness of the workpiece, and in the end at least two layers of veneer should remain intact.

If the cuts face the inside of the part and are hidden from view, there is no point in calculating their number and pitch. Subsequently formed scars can, if necessary, be leveled with automotive putty and sanded to a smooth state. With due diligence, it is possible to calculate the reduction in the length of the arc during bending, using a known angle and radius of bending. In this case, the number of cuts will be equal to the quotient of the arc reduction divided by the thickness of the cutter in the widest part of the entry. The required number of cuts must be evenly distributed over the entire bend radius.

Before fixing on the template, the cuts formed on the plywood are filled high-quality glue for wood, for example Titebond 2. Protruding glue can be immediately removed with a spatula or sanded after drying. While the glue hardens, the plywood is firmly fixed to the template.

You can also make it easier to soften thick plywood by perforating the workpiece. Holes with a diameter of 2-3 times the thickness of the plywood are made with a core cutter or Forstner drill in a checkerboard pattern with a pitch of about 80-100 mm between them. The degree of perforation can be greater; this is determined both by the flexibility of plywood to bend and by the required final strength of the part. Naturally, this bending method is only suitable for hidden technological elements that do not form a finishing plane. If desired, the bent part can be sheathed on one or both sides with veneer or thin plywood, having previously softened them.

Bending according to templates

In the simplest case, the role of a template can be played by pieces of hard plywood shaped like a bending profile. Since most parts are bent along the same contour on both sides, the templates are made in pairs and then fastened together with spacers slightly smaller than the width of the part. Templates can also be different if it is necessary to bend a part of an irregular shape, that is, curved along two axes.

Another type of template is a frame made of beams that does not form an exact bending contour. In this case, the transverse bars are placed at the pressure points, that is, on the most protruding and concave parts of the part profile. For fastening at intermediate points, you can add an arbitrary number of jumpers to the frame.

When making the frame, you need to take into account the type of clamping devices used. Thus, plywood inserts can have holes for clamp jaws, and the frame itself can be equipped with additional stiffening ribs in the direction of pressure and tensile loads. If the part has a uniform bend along its entire length, it can be fixed without a frame, for example, tied with a rope, cable, chain with a screw tow bar, or using sling belts.

Manufacturing of composite parts

You can bend parts of complex shapes by alternately gluing layers of steamed veneer onto a workpiece of the required shape. In practice, this is a method to avoid fiddling with thick parts, because on sharp bends it is much easier to deal with thin sheets due to the small values ​​​​of the permissible radius.

In the simplest case, the base is formed by a relatively thick perforated sheet of plywood, the permissible bending radius of which is obviously lower than the required one. Such a part, most likely, will not have the necessary strength, so it is subsequently “sheathed” with several more thin layers. In each case, an adhesive connection is made over the entire plane; the sheets are pre-softened so that they do not straighten the shape of the core.

Sheathing can be done not only for the purpose of imparting strength. In some cases, one or more outer layers pursue purely decorative function. For example, thin sheets of veneer can hide traces of attaching the workpiece to the template, and plywood will disguise perforations or cuts. It is also possible to paste the part with plastic, laminated veneer and other finishing materials, poorly retaining their shape.

To bend plywood, two conditions must be met: moisture and heat. There is also a dry way to change its shape. You can work with material of any thickness, but the thicker it is, the more time it takes to achieve the result. Bent plywood used in construction to construct arches, spiral staircases etc.

What kind of plywood can be bent?

Thin layers of wood are glued together, positioned in different directions. As a result, the fibers of one layer have a direction of 45º, 60º, 90º with respect to the fibers of adjacent layers. This method of making plywood increases its bending resistance, so it is easier to bend material with a small number of layers. In production it is bent using special equipment, clamping in the matrices. It is pre-treated with steam and thereby acquires sufficient elasticity.

During renovation or private construction, a bent plywood structure may be needed. Then you have to make do with improvised means. But even in this case, the work can be done efficiently if you follow the technology.

Methods for heating plywood

Heating can be done in the following ways:

• ferry,
• in hot water.

Without heating, the work can be done using epoxy glue.

Hot water should be poured into a bathtub or other suitable container big size. The workpiece is immersed in it for about half an hour, as a result the layers of wood are steamed. At home, steam is created using a boiling kettle. Some experienced craftsmen heat up plywood using an iron. The steam supply must be constant, otherwise the wood will cool quickly.

Securing the workpiece

Moistened plywood easily changes shape, but if the bend angle is large, the work is done in stages. The wood is bent to a small angle, dried, then the steps are repeated as many times as possible until the required shape is achieved. If the bend angle is small, you can do it in one go. The next step is to secure the plywood, which can be done in 2 ways:

• the load is installed at the bend, the ends are tied with a rope and supports are installed under them;
• Fastening to the template is done using tape or rope.

In the second case, any curved structure made of rigid material can act as a template. The most commonly used is fiberboard. To make an arch, steamed wood can be secured in the opening using self-tapping screws. Some nuances of steaming wood should be taken into account: in very hot water it can delaminate, so it is important not to overexpose it. A thin layer can steam in 5 minutes. You can use another option: iron the workpiece moistened with water with a hot iron. After this, immediately give the required shape, repeat wetting and heating with an iron.

Watch a video about bending using a ready-made template at the end of the article.

A metal template made of durable steel is also used to secure the plywood, but it bends along with it. This method is preferable for large parts having a complex configuration. The steel strip is tied to the plywood until it is moistened, then its shape is changed. The steel template is untied only after the wood has completely dried.

If a weight is used to secure the plywood, it is important that its width is equal to the width of the workpiece. If it is smaller, only that part of the wood that is equal to the width of the load will bend. Changing the shape of plywood is carried out independently when its thickness is up to 20 mm. It should be taken into account that different breeds Woods have different abilities to bend and unbend. Compression can be performed by 30%, stretching by 2%. Walnut, beech, and ash show good results. Maple, oak, and larch are difficult to change shape.

How to bend large sheets?

It is not always possible to treat a very large sheet with steam. In this case, so-called cuts are made. They are strips that are shaped like a cone. Used manual milling machine. The cuts must be made to the opposite layer, it is important not to catch it, otherwise the material will split. For wood 4 mm thick, the cutting depth is 2 mm.

The steeper the bend radius, the greater the number of cuts. The plywood should then be clamped onto the template, and a thin layer of veneer glued to the outside of it. The glue used is epoxy or PVA. Drying time: approximately 1 day. Thus, the workpiece is hollow at the bend, but can withstand heavy loads.

Very often during the construction or renovation of houses there is a need to obtain curved surfaces of plywood sheets.

In construction, repair or furniture making, there is a need to bend plywood and obtain curved surfaces.

This raises the question: how to bend plywood so that the bend is strong and does not crack? You can perform this procedure yourself.

Bending at home

When bending wood, there are a number of difficulties that are associated with the structure of the material, as well as with the technological features of this process:

The thinner the plywood sheets, the better and easier it is to bend them.

1. The thinner the material, the easier it is to work with. However, it is necessary to take into account the fact that to construct, for example, an arch, the plywood must have a thickness of at least 10 mm. That is, you need to bend an already quite thick puff pastry.
2. When making plywood, layers of veneer are placed under different angles to each other. This is done in order to increase the bending resistance of the material.

There are several ways to bend plywood at home, the most popular of which are:

• humidification (steaming);
• incision;
• gluing.

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Steaming

In workshops and special workshops, bending and the required curvature are achieved quite simply. To do this, the part is saturated with steam, after which it comes under the influence of a special vice, which bends it to the desired radius of curvature.

At home, this procedure is quite difficult to carry out, since it is very difficult to find a suitable container with constantly boiling water. Therefore, only small pieces of plywood can be bent in this way. To do this, you can use an iron with a steam function or hold the material over a container of boiling liquid for a certain time.

An alternative to steaming is to dampen the plywood. To do this, pour into a container of the required dimensions (for example, into a bathroom) hot water, after which the workpiece is immersed in it for a certain time, which depends on the direction of bending and the thickness of the sheet. Below is a table for calculating the boiling time of plywood at a temperature of about 95°C.

As a result of this procedure, the layers of wood are steamed. After steaming, the wood is bent by a small angle and fixed in this position in several ways:

• a load is placed in place of the bend, the ends of the plywood sheet are tied together with a rope, and supports are mounted under them;
• The plywood is fixed in a prepared template, to which it is attached using rope or tape.

Then the workpiece is dried and used for its intended purpose. Steamed plywood easily changes shape, but if you need to create a large bending angle, then such work should be done in stages. Therefore, all procedures are repeated as many times as necessary to achieve the required bending value.

An alternative to steaming is to soak the plywood in warm or cold water. In this case, you should take into account:

• for soaking at a water temperature of 60°C, the time must be increased by 1.5-2 times;
• for soaking at a liquid temperature of 20-30°C, the time increases by 15-20 times.