While making a product that contains plywood, I was faced with the fact that it was damaged by long and improper storage. Yes, it was so decisive that a sheet of plywood can be used instead of a propeller. The photo shows a blank cut from the straightest part of the sheet, and then, I think, everything becomes clear to everyone.
After wandering around the vastness of the network, it was decided to try to level the plywood blank.
So, we will need:
- Water;
- Rag;
- Iron;
- Oppression.
First, we need to find a flat surface sufficient to accommodate our workpiece size. Take a wet rag and wet the bends with it.
The water will be readily absorbed, so you need to be careful not to overdo it. Otherwise, the plywood may delaminate. Let the rag sit for a while and repeat this procedure with reverse side. When the plywood is a little saturated, we take a heated iron in our hands and boldly begin to warm up the soaked areas. In theory, heat and water make the plywood pliable.
Having steamed the sheet in this way, place it on a flat surface under pressure. I used buckets of water and a homemade weight as pressure. We leave our patient in this state until he dries. In my case - at night.
In the morning my sheet looks like this:
In principle, this result should be enough for me. If it is necessary to obtain an even more even surface, then these operations can be repeated by increasing their intensity (I was cautious due to inexperience). And then everything should work out for you.
The unique patterns of veneer surfaces are worth refinishing, especially the coatings old furniture, for which the plywood was selected and finished with great care. Fortunately, even serious damage, if limited in small areas, can be repaired with almost no traces. On older plywood, the most common problem is "bumping" or lifting caused by the breakdown of previously applied animal glue. This glue softens when exposed to heat, and the plywood can be repaired by melting the glue with a warm iron and pressing down on the raised areas. Place a damp cloth between the plywood and the iron. Once the area is completely flat, place a stack of heavy books on it until the glue sets (usually a few hours). If the glue has lost its bonding properties, you will have to cut the plywood, scrape it off and apply fresh adhesive. Surface flaws, gouges and burns on old and new plywood are corrected with patches.
Elimination of plywood blisters
Cutting through plywood . If the plywood has lifted, causing a "bubble" to form in the middle of the surface, use an edger, guided by a metal ruler, to make a diagonal cut across the grain of the plywood, passing through the bubble. Make a second diagonal cut across the first in the middle of the swelling, forming an X. Be careful not to cut directly across the structure; this will leave a noticeable line on the repaired surface. If the swellings are small, it is enough to make only one long incision.
If the plywood has lifted up along the edge of the surface, you can scrape off the old glue from the surface without cutting the plywood. If you can't scrape down the innermost part of the area, make a cut in the plywood either parallel to the grain, or diagonally if the edges are parallel to the grain (see illustration).
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| Elimination of plywood blisters. Cutting through plywood | Elimination of plywood blisters. Removing old and applying new glue | Elimination of plywood blisters. Shrinkage of the adhesive and rolling of the glued surface |
Removing old and applying new glue . Using a tool with a thin, flexible blade, such as a putty knife, carefully lift one half of the bulge or raised edge and use the sharpened edge of an edger to scrape away any old adhesive from the bottom of the plywood and the top of the underlying surface. If the plywood is stiff and does not bend easily, moisten it with a few drops of water. Scrape down the glue underneath other areas in the same manner, stopping occasionally to knock off bits of old glue.
Once the inside of the bulge or raised edge is clean and dry, apply a thin layer of PVA glue to the underlying surface, using a glue injector, small putty knife or brush to get to the inside sides. After this, press the plywood into place and immediately wipe off any remaining adhesive.
Glue shrinkage. Iron the repaired area with a wallpaper seam roller, first with light, then with more force. Wipe off any glue that is squeezed out and cover the area with a piece of rough tissue paper. Lay flat wooden block, slightly larger than the repaired area, onto the paper and press it down with a weight (see picture) until the glue dries. Alternatively, you can clamp the repaired area with a girdle clamp. Place protective wooden spacers between the clamp and the surface.
Remove the weight and paper. If pieces of paper are stuck, gently remove them with a chisel, holding it with the slanted edge down. Apply a new finish to the repaired area.
Plywood patch
Cutting the patch . Using an edging knife guided by a metal ruler, cut out a patch of new plywood that is slightly larger than the damaged area. Plan the patch so that its structure runs parallel to the structure old surface and matched its texture as closely as possible. To prevent a visible blunt cut line from forming on the structure, make a diamond-shaped patch (as shown) if you are repairing damage in the middle of a veneer surface, or a V-shaped patch if it is for split edges or corners. Cut the patch with repeated light strokes of the knife and bevel the edges slightly inwards, tilting the tip of the knife towards the patch at an angle of about 10° so that down side the patch was slightly smaller than the top one (see figure).
Surface marking . Place the patch on the damaged surface, aligning its texture with the structure of the surface, and outline it with a sharpened pencil. Using a ruler and a trimming knife, make a cut along each pencil line to create an indentation for the patch. Bevel the cuts at a 10° angle toward the center as shown. Cut old plywood all the way to the end, being careful not to make a cut beyond the corners of the diamond-shaped recess.
Many woodworkers achieve a fine fit by placing new plywood on the damaged area and making a cut through both layers at the same time. This method is the best when working on thin modern plywood.
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| Plywood patch. Cutting the patch | Plywood patch. Surface marking | Plywood patch. Clearing the depression |
Clearing the depression . Starting at the center of the damaged area and working towards the edges, remove the old plywood from inside the diamond-shaped recess with a chisel, holding it sloping side down. If the plywood is too hard and won't "relax", lightly tap the angle of the chisel with a hammer. Use a chisel to scrape away any remaining glue and dirt deposits from the bottom of the recess, stopping occasionally to dislodge any hardened parts. If the surface underneath the plywood is damaged, smooth it out with wood filler. Allow the filler to dry before applying glue to the patch.
Fitting the patch . Lay the patch over the recess to determine its size, then file the edges for a precise fit. Try to maintain sloped edges and file only in the direction of the grain to avoid removing the corners of the patch. After adjusting it, apply a thin layer of PVA glue to the bottom of the recess with a brush, press the patch into place, roll it and place a weight on it.
Sanding the patch . Once the glue has dried, sand the patch a little so that it is flush with the surface. Do this with very fine sandpaper wrapped around a flat cork or felt-covered sanding block with slightly rounded edges. Sand in the direction of the grain using light pressure. Once the patch is flush with the surface, apply a new finish to the repaired area.
Plywood is the most popular material in construction industry. This is due to its low cost. This is both a plus and a minus. The lower the price, the more susceptible it is to moisture. The question arises: how to impregnate plywood for moisture resistance and how to increase its strength?
Plywood is construction material, consisting of several veneer layers connected to each other. How moisture resistant it is depends on the composition of the glue that binds the layers. Highly resistant to moisture is a material in the production of which bakelite varnish or glue is used. They can withstand direct exposure to water. Thanks to this, the material can be used to make boats and other swimming equipment without having to additional treatments. There is only one “but” – the price is too high.
Other materials best suited for construction work and furniture manufacturing, with high humidity begin to delaminate and rot. You can increase the protection of plywood from moisture by impregnating it with special substances. It should be noted that some of them cope with their task with dignity.
On video: which plywood is better.
Processing methods
Processing plywood and protecting it from moisture can be done in several ways. Here are some of them (the most common in everyday life):
- puttying with PVA glue;
- coating with drying oil;
- treatment with nitro paints;
- gluing fiberglass.
PVA
Protecting plywood from moisture and rot with PVA putty has many advantages. It reliably protects the material from many negative factors. We present step by step instructions, how to perform the protection process:
- Before treating the material to increase moisture resistance, it is placed parallel to the floor and a layer of PVA glue is applied.
- Allow time for the initial layer to be well absorbed, after which it is covered with another layer of PVA.
- Continue the process until glue stains begin to appear on the underside of the sheet.
- The plate is turned over and the impregnation process is repeated.
After the work is completed, the slab is laid on a flat surface and allowed to dry under natural conditions. The disadvantages of this process include rather long processing times. Plywood will have to be protected from moisture for 3-4 days.
A similar impregnation can be done using epoxy resin. But this is quite an expensive pleasure and at the same time not harmless to human health. Sheets treated with epoxy resin are used for exterior use only.
Drying oil
Drying oil is the simplest way impregnation of plywood board from water. Processing is carried out in the following way:
- The solution (oil for plywood) should first be heated to a temperature level of 60 0 C, due to this its penetrating ability increases.
- Then we impregnate the horizontally located sheet with drying oil using a brush.
- After completing the impregnation process on one side, we proceed to the other.
- Be sure to thoroughly coat the ends of the plywood.
- When the first layer is applied, we begin to force-dry it using an iron or hair dryer.
- After drying is completed, we begin the repeated process of applying drying oil and forced drying.
The number of layers may vary. Stop treating with drying oil only when the solution stops being absorbed by the material (the water-repellent effect is fully achieved).
After this treatment, paint or varnish can be applied to the plywood. The question often arises about how to cover plywood on the floor. This method is ideal for this purpose.
Fiberglass
You can also protect plywood with fiberglass, but for this you need to use waterproof varnishes that do not contain epoxy or polyester resins. The protection technology consists of the following steps:
- The sanded plate is painted with varnish.
- After allowing the applied layer of varnish to dry for about two hours, fiberglass is glued onto the surface of the plywood.
- Re-apply a layer of varnish to the ends of the slab and leave until completely dry.
- The treatment is completed by applying another layer of varnish and drying the impregnated plywood under natural conditions.
Advice! If fiberglass is not available, you can use regular gauze. After it has been painted with varnish, it will reliably protect the material.
Nitropaint
Another way to treat plywood from moisture is with nitro paints. This is especially true when the material will be in direct contact with water, for example, when repairing a boat or arranging a damp room.
Here are instructions for doing the work yourself:
- Initially, it is necessary to sand the surface and cover it with drying oil.
- Allow the drying oil layer to dry completely and apply liquid paint as a primer.
- Apply a layer of nitro paint to the sheets protected with primer.
- We cover the surface of the plywood with a cloth, which at the same time must be impregnated with nitro solvents.
- After drying is completed, it is treated a second time with diluted nitro paint. The resulting moisture-resistant material is even suitable for making a boat.
Important! Last layer The nitro paint is made quite thin. Otherwise, the degree of strength decreases.
Surface preparation
Before impregnating plywood from moisture, its surface must be prepared. This process consists of several stages:
- The slab is drying. It should be such that the plywood is protected efficiently.
- Next comes grinding the surface. Before impregnating the plywood for moisture resistance, it is necessary to clean it thoroughly. To do this, use fine-grained sandpaper. For ease of operation, it is attached to a wooden block, and the surface is polished with this device.
- Particular attention is paid to the ends of the sheet. All chips and burrs are removed. If the chips are quite large, you can use wood putty.
Cleaning can be done using grinding machine. Sanded by hand does not have the same surface quality as using special tools.
It is advisable to acclimatize the plywood; how long this process will take depends on the temperature. If the material is intended to be used indoors, then one day is enough for drying; outdoors at a temperature of 8 0 C and below - 3 days.
Important! The slabs are soaked for some time, and then they must be stacked on a flat surface to dry completely.
Now you understand how to treat plywood to increase its moisture resistance and hydrophobic qualities at home, and you don’t have to buy products expensive brands. You can use quite in effective ways processing presented above.
You can make many useful things from plywood: furniture, shelves, partitions, various stands, etc. However, in order for all this to be complete and beautiful, it is advisable to give homemade products different shapes, including round ones. In this case, the question arises: is it possible to bend plywood yourself and how to do it? To answer this you need to know existing technologies and methods for this process.
Stages:| Options for bending plywood. Features and nuances of performing various methods. | |
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Selection of materials. Sold in specialized retail outlets different quality size and thickness of plywood, so it is extremely important to choose the most optimal option. |
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Bending a material by heating or cutting the workpiece. |
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Bending thick plywood. Features, options. |
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Tools for performing work. |
How to bend plywood at home: features
In order to bend plywood correctly, it requires moisture and heat. It is also possible to use the dry option of changing the shape of the tree. These methods are applicable to plywood of any thickness, but you need to take into account that the thicker the material, the more time it takes to obtain the required result. Scope of use bent plywood wide enough - from construction work (cladding spiral staircases, production of bases for arches, etc.) to the production of bent furniture.
Choosing plywood for bending at home
Since this material is made by gluing thin layers trees that are located in different directions, then the bending resistance increases. For this reason, you should use thin plywood for work, since it has fewer layers. In factory conditions, its bending occurs on specialized equipment. The material is given the required elasticity by pre-treating it with steam.
At home, when renovating an apartment or private house, structures with a rounded shape are often needed (for example, when arranging an arch). You can make them yourself from bent plywood. By following the technology, it is possible to obtain a high-quality product, despite the use of improvised means.
Plywood is sold at construction markets and at special outlets (specialty stores, supermarkets, etc.). When choosing, you need to pay attention to the flexibility of the material, which is produced with a thickness of 3-4 mm. As a rule, it is used to create arches in doorways or when moving from room to room. After processing, a workpiece made of a similar material is attached to the frame with screws.
IN Lately was noticeable on the market similar plywood made in China. It combines affordable cost and suitable quality. There are several methods that are used to create bent structures:
- gluing;
- cuts;
- steaming;
- various combinations of the above methods.
How to bend plywood at home (video): heating
This process can be accomplished using the following methods:
- immersing the workpiece in hot water (temperature - 60 o C);
- using superheated steam;
- soaking in warm liquid (rarely used, as it increases the time of the entire process).
If there are no conditions and possibility to bend the material using the above methods, you can use epoxy glue.
To use the superheated steam technique, some experts create steam using a boiling kettle, or less often, an iron. But since the steam supply must be constant, it is quite difficult to obtain steam in the required quantity at home. For this reason, the first option is more popular for independently obtaining the required plywood shape.
Hot water should be poured into any open container - a bathtub is best, since its volume makes it possible to make bent products of quite large sizes. The plywood blank is immersed in hot water for about 30 minutes. During this time, the wood will be able to expand to the desired size. A wet workpiece will easily change its shape, however, it should be borne in mind that if it is necessary to bend the plywood at a large angle, the entire process will need to be carried out in several stages:- first the bend should be done at a small angle;
- the material is again immersed in hot water;
- after 30 minutes, the procedure is repeated, the bending angle increases;
- the technology is repeated until the plywood takes the desired shape.
But you need to take into account that when the workpiece is soaked, it may delaminate. If the thickness of the plywood is too small, 4-6 minutes may be enough to bend it. In some cases, an iron is used. The moistened material is ironed with a heated iron and immediately given the required shape, after which it must be moistened again and ironed with a heated iron.
In order to process large leaf steaming plywood on your own does not always provide suitable conditions. In this case, to obtain the required result, cuts are made in the material according to the type of strips with a cone shape. For similar work a hand-held electric tool with a cutter installed on it is used.
Such cuts must be made extremely carefully, otherwise chips may form on the material.
For a workpiece 4-5 mm thick, the depth of such cuts should not exceed 2 mm, and their number directly depends on the steepness of the desired bending radius. That is, the larger it is, the more cuts will be required.
After this, the material is clamped onto the template. The outer layer is covered with a strip of veneer, for which epoxy glue or even PVA is used. The plywood takes about a day to dry. The result is a hollow workpiece that can withstand fairly heavy loads.
Fastening the workpiece. Video
In order for the shape of the plywood to be stable, it must be secured. This work can be done in several ways:
- Any heavy object is placed at the bend, the ends are tied with rope and supports are mounted under them.
- The workpiece is secured to the template using cord, rope or tape.
The first method is absolutely clear, however, it will be necessary to check the design, since the plywood may move slightly away from the required angle during the cooling process. The second method involves using a template, which can be used as almost any design with necessary angles fold for the future part. Very often a do-it-yourself fiberboard template is used. If you need to make an arch, then the steamed workpiece can be installed directly in place, clamping it with screws in the opening.
Steel templates can be used to fasten plywood. They bend along with the wood. This technique is used for the manufacture of large-sized parts with complex shape. The steel strip is attached to the plywood before lowering into the bath. After this, it is folded together with the workpiece sheet. Detaching occurs only after the workpiece is completely dry.
When using a weight to secure the material, you should be careful and try to ensure that it is equal in width to the workpiece sheet. If this is not the case, then only the part of the plywood that was equal to the width of the load will be bent. Similar options are used for wood with a thickness of no more than 2 cm. In addition, it should be borne in mind that different varieties trees can bend in different ways.
The maximum effect can be achieved if the plywood was made of ash, walnut or beech. Experts do not recommend using sheets of oak, maple or larch for bending plywood. As a rule, wood can be compressed by 25-33% and stretched by 1.5-2.5%.
How to bend thick plywood at home: video
If you need to do bent product made of plywood with a thickness of 1.5 to 2.2 cm, then, as a rule, the option of cutting its surface with a cutter is used. The depth of the cut should not exceed half the thickness of the sheet of material. It can reach a layer with the opposite direction, but not go deeper into it. Otherwise, the workpiece will split. There is no exact definition for slot width as it can vary. It is quite possible that the bend angle on one side of the material will be greater than on the other. This method can be used to create the walls of a boat.
The plywood is bent to the required angle and clamped into the mold. The veneer strip is glued on top. Drying – 24 hours. The gluing procedure itself is possible both with cuts outward and inward - the level of rigidity of the part will not change. It’s just that in the first case, voids are formed.
There is another option for obtaining products from thick plywood - adhesive. In this case, a bent workpiece is cut with an allowance of 2-6 mm from thin material. Simply put, a pattern is created that is applied to the sheet in such a way that finished part plasticity and direction of the veneer were alternated to obtain the required rigidity. The layers of plywood should be glued together using an epoxy compound, after which the workpiece is clamped with clamps for a day, which will give it the desired shape.
When the product is completely dry, you will need to sand it and grind off all the irregularities along the edges.
To obtain a quality product, it is important to follow these recommendations:
- for the safety of the received parts, the humidity level in the room should not exceed 9-11%;
- the bend radius across the wood fiber should be smaller than along it;
- steamed or soaked in hot water materials need to be bent while they are still warm.
In order to obtain a sufficiently complex bent structure, it is better to contact specialists with professional tools, experience and skills.
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's easiest to work with thin slabs, however, their scope is limited 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, it must be used high quality plywood. 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:
- The workpiece of the required size is placed in water for certain time. You can understand that the product is ready for further transformations by carrying out regular monitoring. The slab will become pliable.
- Soaking stops when the desired flexibility is achieved. The sheet itself is moved to comfortable spot for work.
- 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 recesses in 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:
- Frequent incisions are made in a specific location.
- The workpiece is given required form by fixing it in the required position.
- Using PVA or epoxy resin dense veneer is glued.
- After about 24 hours, the fasteners are removed.
It is best to place the cuts with 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 sheet of plywood large thickness, you should consider using multiple slabs. 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 in mandatory clamps are 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. For achievement 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.
Number of layers | Thickness in millimeters | Time, min. |
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 an excellent material for carrying out finishing works and furniture production. The ability to create curves opens up interesting design possibilities. 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 can be used for thin sheets doesn't make sense. 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.