How to treat MDF from exposure to water and moisture • Video description

If MDF surfaces have to constantly come into contact with water, then this can have a very detrimental effect on them. Therefore, before covering something with MDF, you should think about whether this material needs additional protection.

You can protect MDF from moisture using various means. Drying oils, such as PVA glue and vinyl film, have proven themselves to be good for these purposes. Let's consider each of the above methods for treating MDF from moisture.

Protecting MDF with drying oil

Perhaps the most inexpensive way to treat MDF so that the boards do not rot during use is to apply drying oil to their surface. It would be advisable to note that this method of protection is applicable only in cases where MDF is used as flooring for leveling floors.

In this case, special attention is paid to the ends of the MDF and the seams between them. It is better to treat these areas with drying oil several times, since they will absorb it very well.

Processing MDF with PVA glue

Protecting MDF with PVA glue is applicable precisely in cases where the ceiling or walls are sheathed with slabs. It is a known fact that PVA glue has good performance in terms of water resistance and reinforcement. Therefore, MDF panels treated with PVA glue last much longer.

As with the first method of protection, PVA glue is applied to MDF with a brush in one or two layers. Before applying glue, dust and other contaminants should be removed from the surface of the boards so as not to disrupt the adhesion of the materials.

Gluing vinyl film to MDF

Previously, the construction magazine samastroyka.ru already talked about the positive aspects of vinyl film. This material can be used for various purposes, including to protect MDF surfaces from moisture.

Vinyl film can not only protect MDF from the harmful effects of water, but also significantly improve their appearance. As a rule, this method is perfect in cases where the slabs are used indoors.

Gluing vinyl film to MDF boards is quite simple. The main thing is that the surface of the panels is clean and free of dust. Vinyl film is not glued to the ends; for these purposes it is best to use special protective corners, like on furniture.

There are many different ways to protect MDF from moisture. The main thing is to choose the right one that is most suitable for a particular situation.

How to treat MDF against water?

How and how can you protect MDV from water?
Perhaps there are some special impregnation compositions? To be honest, creating waterproof material from ordinary MDF is not true. You can go and buy waterproof MDF.

Waterproof MDF comes out at the production stage.

Firstly, it is an adhesive based on urea-melamine resins, and secondly, it is a paraffin mixture that is introduced into the mass from which MDF is made.

Compared to ordinary MDF, waterproof MDF is even the densest material.

At home, creating at least something similar is simply impossible.

Therefore, there are only two ways, the most difficult is PVC film, and from both sides, because moisture will penetrate onto the inside of the MDF.

And the second way is the easiest, cover the MDF with a special varnish (and the ends too).

For example, yacht

We coat it with varnish on both sides.

There must be at least two layers of varnish.

But I’ll say right away that this is all temporary, the varnish will have to be renewed every three years (this is approximately).

From everything that has been said, we can come to the conclusion: If the room is wet, then use water-resistant MDF.

If you mean MDF doors in the bathroom, then you do not need to protect the MDF, but to create good ventilation in the bathroom and install the doors correctly (at least 2 cm at the bottom).

MDF is very easily damaged by moisture, you don’t even need to come into direct contact with water, but rather just a wet environment, for example an unheated room - how important MDF will immediately begin to swell, thicken, spin and all its beauty will simply fall apart!

To protect MDF from water, you need to realize that the front side is not all that needs to be covered, the back side and edges of the panels also need to be covered with a protective compound!

In other words, you will not just have to paint the walls with the necessary composition, but will have to disassemble all the panels and completely process them, from all sides, and only later put them back together!

Now about the compositions that can help you!

You need something based on silicones, resins or waterproof adhesives!

The choice is enormous, for example, the strengthening impregnation-primer Rainbow 26 will cope with this task quite well.

But remember, you must cover it twice and on all sides!

The first layer will close all the pores and stick well to the MDF, and after the first has dried, the second layer will create a good-quality protective film.

MDF is an inexpensive, environmentally friendly material (medium density fiberboard made from wood dust based on glue), which is widely used for the production of various facades, including kitchen ones.

MDF Facades come in different prices and quality. Depending on the price, the MDF facade can be of different classes and, accordingly, different technical features. The cheaper MDF, the faster it fades and its structure is destroyed.

What kind of MDF facade do you have? Maybe it's plastic that won't swell with water or warp with a water-resistant coating.

But if you still want to cover old facades with something, you need to literally know the material from which they are made, whether they are covered with PVC film. Here are the primers that provide a waterproof effect: DUFA on an alkyd base, Semin Anti-Humidite WP 94 (moisture barrier primer). A good high-quality oil paint or nitro paint can also help you.

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Share114-08-2015 10:52:47

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Is it possible to make MDF moisture resistant so that the material works in a really humid environment, in direct contact with water? It is planned to glue several sheets and then profile them with a milling cutter. I’m thinking of soaking it through with diluted varnishes and resins and also gluing it with resin or waterproof glue. Polyester, which was recommended in the next topic about gluing, is not suitable - it is not moisture resistant.

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about 10 years ago we sold an insulating agent from Barpimo, they positioned themselves by the fact that a part treated with it would lie in water for a day without harm, we used it when it was necessary to put nitro or polyurethane on acrylic

Share314-08-2015 16:29:03

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about 10 years ago we sold an insulating agent from Barpimo, they positioned themselves by the fact that a part treated with it would lie in water for a day without harm, we used it when it was necessary to put nitro or polyurethane on acrylic

As I understand it, this information is not relevant now. Their website hasn’t been updated for two years, but are there any analogues in Russia?

How to treat MDF from water?

If MDF surfaces have to constantly come into contact with water, then this can have a very negative effect on them. Therefore, before covering something with MDF, you should think about whether this material needs additional protection.

You can protect MDF from water using different means. Drying oils, for example, PVA glue and vinyl film, have proven themselves well for these purposes. Let's look at any of the above methods for treating MDF from water.

Protecting MDF with drying oil

Perhaps the cheapest method for treating MDF so that the boards do not rot during use is to apply drying oil to their surface. It will be useful to see that this method of protection is applicable only in those cases where MDF is used as a flooring for smoothing floors.

With all this, special attention is paid to the ends of the MDF and the seams between them. It is better to treat these areas with drying oil a couple of times, as they will absorb it very well.

Processing MDF with PVA glue

Protecting MDF with PVA glue is applicable precisely in those cases where the ceiling or walls are sheathed with slabs. It is a recognizable fact that PVA glue has good characteristics in terms of water resistance and reinforcement. Therefore, MDF panels treated with PVA glue last much longer.

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What is MDF used for?

Before you learn about the process of painting MDF, you need to find out about its qualities and where this material can be used. So what is MDF for? MDF stands for finely dispersed fraction. This is an engineered wood that is made from a mixture of wood fibers and glue using the hot pressing method.

For some types of furniture, MDF is better suited than for others. The main disadvantage of MDF is that the material does not react well to contact with moisture or liquids. If it gets wet, it swells right there. This is why they try to avoid using MDF in the kitchen and bathroom.

Plywood impregnation technology

In European countries, kitchen furniture made of plywood is extremely common. This is an inexpensive material that can be easily processed. It is easy to saw, drill, and install. It is perfectly compatible with metal, glass, and plastic. When treated with clear varnish, plywood kitchen furniture retains the natural texture of the wood and looks solid.

You can make a kitchen set with your own hands, but it is not recommended to use ordinary plywood for this - it is extremely susceptible to the negative effects of moisture. It is necessary to use plywood with a high degree of moisture resistance or treat the plywood with special impregnations or paints and varnishes.

What disadvantages does this material have?

If you are planning to paint MDF furniture, there are a few rules to keep in mind. The most important thing is that if you work with MDF incorrectly or cut it, you can get hurt. Therefore, always wear protection when working with this material, especially if you are sawing it. Therefore, for this type of work you simply need a protective mask that will fit tightly on you.

MDF reacts poorly to water. Therefore, it is not allowed to use paints and varnishes on an aqua base. If a huge amount of water gets on MDF, then most quickly the material will change its shape irrevocably. You can reduce the risk of such damage by properly preparing the surface with primer and appropriate paint.

Types of varnishes

Instead of painting, you can choose varnish. To reliably varnish MDF, you need to apply several layers and wait until it dries completely each time. The process will take a long time and require effort.

If you still decide to choose a varnish, then pay attention not only to its cost and composition, but also to wear resistance, resistance to humidity, and high temperature. To coat MDF boards at home, you can use several different types of varnishes.

The cheapest compositions in this segment are alcohol-based and have a short drying time (up to half an hour), that is, they are quick-drying. Traditional inexpensive varnishes include oil-based varnishes, which not only give a beautiful appearance to surfaces, but also effectively protect them from moisture.

Note! For coating MDF countertops, an excellent choice would be two-component epoxy varnishes, which are characterized by increased resistance to impact.

Acrylic varnishes are good because they are odorless, do not emit toxic substances, and are not washed off or diluted with water. Another popular option is polyurethane varnish. It is characterized by enviable wear resistance and good adhesion to wood-based materials.

As for those cases where further polishing of MDF products is expected, nitrocellulose varnishes are the best option.

MDF surface preparation and sanding.

MDF does not require harsh preparation before painting. But, if you want to make beautiful, long-lasting furniture from MDF, there are a couple of steps you can take ahead of time. Before applying the primer, you can lightly sand the surface using medium-grit abrasives (120P should be fine). Make sure you take extra care to sand the edges; if they are not smooth enough they will not absorb the paint well.

Sanding the MDF surface allows the primer and paint to adhere perfectly to it. For work, use soft sandpaper, which will help polish the material. When you sand MDF, it is imperative to ventilate the room. Also, do not forget to wear a protective mask and goggles.

After you finish the sanding process, you must remove all dust from the surface of the material. If even a few dust particles remain, this greatly affects the adhesion of the paintwork. Keep the area where you work clean.

Why do interior doors swell?

Why do interior doors swell? Most often, when asking such a question, they mean, for the most part, doors to the bathroom or toilet. Less commonly, other interior doors swell. But this also happens. It’s especially disappointing when the doors have only recently been installed. Then stones fly into the garden of careless door installers. Not always, the cause of deformation and swelling of interior doors is the work of people.

Why do interior doors swell?

• What reasons contribute to the swelling of interior doors!?
• And how to avoid this, warn!?

We'll tell you in the article

The door does not close tightly due to deformation The door does not close tightly due to deformation

The door stopped closing and swelled. Why? If the doors are made of MDF, laminated chipboard or solid wood, the reason for their swelling is the increased humidity in the room. In addition to poor or insufficient ventilation. In such conditions, swelling and deformation of doors is inevitable

Which doors are more likely to swell and deform?

It is worth saying that the doors that are most susceptible to swelling are those in the bathroom or toilet. And also, if the door is installed between an unheated corridor and a heated room. Under such conditions, condensation forms. Which, over time, is absorbed into the door leaf.

How to apply primer?

The edges of MDF are quite porous, so you need to seal these areas especially well. You need to cover the MDF with 2 or even 3 layers of primer before testing the material (insulating primer + main primer). For the best result, between applying layers of primer, you can lightly sand the surface. Wait about an hour before applying paint, otherwise the primer simply will not have time to dry.

For thin sheets, it is good to prime both sides of the MDF. After all, this is such a porous material that paint can penetrate from the back side. You can prevent this by coating the back of the MDF with several coats of primer, even if you don't plan to paint it.

Between applying layers of primer, you can lightly sand the surface.

Primer coating and sheet edge treatment

Learning how to paint MDF is quite simple. But, before you start painting, you need to remember to create something very important. As mentioned earlier, MDF edges in particular are excellent at absorbing water. Despite the fact that MDF primer works exceptionally well on the front side of the material, special attention must be paid to the edges.

There are several materials you can use on the edges before painting. Whatever filler you choose, the technique will be similar - apply the product, sand it, add another layer.

Ceiling finishing

However, finishing work on the balcony is not limited to wall decoration. In addition to the walls, there is also a ceiling?

Most often, the ceiling is finished using the same materials as the walls, and insulated in the same way.

However, when finishing the ceiling you need to take into account some nuances:

• The space between the ceiling slab and the ceiling sheathing should be large enough to accommodate lighting fixtures.
• If the height of the balcony is small, then for finishing the ceiling it is better to use a material several tones lighter than the finishing of the walls. This technique visually increases the height of the balcony, and you will feel more comfortable in this room.

As you can see, there are several finishing options, and here we have mentioned the most common ones. So before you decorate the inside of the balcony with your own hands, spend some time studying the whole variety of materials - and you will definitely find what you need.

What paint is best suited for MDF?

There are several methods to paint MDF, and there are many paint options you can purchase. Introducing the right type of paint makes a big difference in the end result. So what paint is best for MDF?

As you already realized, MDF and water are not compatible. On a theoretical level, if your MDF sheet has been perfectly coated with primer, water-based paint should not damage the material. But, the introduction of such paint carries certain dangers. Water causes the wood fibers in the material to swell, and this simply cannot be corrected. Sometimes this can be sanded down, but most often it is irreparable damage.

Conventional emulsions will most quickly give an uneven result, and the paint can peel off very quickly. Instead, you should choose paints based on PUR or acrylic, the result will be even better.

The last thing you need to consider is what type of matte varnish will suit your paint. . For different projects, you can choose a matte paint, a paint with a glossy sheen, or something that will help achieve an intermediate result.

How to keep your kitchen set in perfect condition: advice from furniture makers

• Stains. Used for boards made of pressed chips after lamination. The liquid makes the texture more pronounced, improving the appearance.
• Varnish. The colorless option is chosen for its protective function. Different tones of varnish are used for decorative purposes.
• Water-based acrylic composition. Requires pre-treatment of chipboard as it is easily absorbed.
• Latex composition. Water-dispersed paints and varnishes provide reliable protection against liquid ingress. The disadvantage is the high cost and difficulty in removing the coating.
• Alkyd enamel. The advantage of this primer is the possibility of application without preliminary surface preparation. This treatment will increase primer consumption.
• Spray paint is also suitable for priming purposes. This option is suitable for a small chipboard surface.

How to paint MDF

Once you have prepared and primed the MDF sheets, it's time to start painting. It's best to start with a thin layer of paint. This will allow you to realize how absorbent your MDF sheet is.

If you have prepared the material properly, you will notice that the paint does not dry immediately. If you see that the paint is drying very quickly, finish painting and sand the surface again. This will save you a lot of time.

Usually two or three coats of paint are required for an MDF sheet that has been properly coated with primer. Do not forget that between applying layers of paint the surface must be sanded. Start with a coarse-grained skin and gradually change to the softest one.

Composition, advantages and purpose of plates

MDF is wood fiber board. They are an environmentally friendly material and have an average density. This material has gained enormous popularity due to its features and properties:

1. MDF panels have the highest level of water resistance. They do not deteriorate when exposed to water.
2. Not bad resistance to high temperatures.
3. Strength.
4. Affordable price. This building material is even cheaper than natural wood.
5. Resistance to fungi and microbes.
6. Easy to care for.
7. The ability to produce products of any shape.
8. MDF can be coated with special varnishes, paints, and enamels.

Advantages of varnishing

The varnish can ruin the coating of the panels (corrodes it). However, when applied carefully, this finishing method has several advantages:

• increasing the strength of particle boards, MDF becomes resistant to mechanical loads, and the likelihood of damage due to impacts is reduced;
• resistance to temperature influences increases, MDF does not lose its shape when the value of this parameter increases, thanks to this it becomes possible to place hot dishes on the surface of chipboards;
• varnish improves the external properties of the panels; there are compositions that allow you to obtain a glossy surface, pearlescent, matte and other types of materials;
• used for finishing surfaces inside and outside the object;
• the ability to maintain its original shape under the influence of moisture is retained, the panels do not swell;
• resistance to fungi;
• provides protection against chemicals;
• the varnished surface is easy to clean, partly due to the increased moisture resistance of the panels.

As a result, the service life of particle boards increases. They can be installed even for operation in difficult conditions: under the influence of high temperatures, with increasing humidity.

Why varnish

Coating MDF panels with varnish is often required. Why? There are several circumstances.

1. The varnished surface simply copes with the increase in ambient temperature. For example, you can place hot dishes on a varnished table made of MDF.
2. Using varnish you can create various decorative effects. It could be gloss, matte-silky surface, mother-of-pearl, etc. It’s striking that similar effects are used for both interior and exterior decoration.
3. High-quality varnishes will not make MDF panels the least environmentally friendly.
4. The coating significantly increases the service life of the product.

There is one drawback. Varnished or painted structures/slabs are more expensive than ordinary ones.

In what cases is it necessary to impregnate plywood from moisture?

Special water-repellent impregnations for plywood are used to make the material more moisture-resistant and resistant to fungus and mold. This procedure is required when creating kitchen furniture from plywood.

• A kitchen is a room where the material will be affected by temperature changes and high humidity (including direct exposure to moisture), from which the plywood must be reliably protected.
• Application of moisture-resistant coatings increases the durability of plywood kitchen furniture. And the use of paints and varnishes will add resistance to mechanical damage and water to the surfaces.
• Using impregnating compounds and paints and varnishes, you can give plywood the required shade and color, creating kitchen furniture that will ideally match the color scheme of the room, textiles, etc.
• Plywood is a convenient material for creating artistic elements that are used in the kitchen for decorative purposes - decorating facades, hood domes.

How to coat fiberboards

A special varnish is used to treat surfaces. It helps to create a smooth coating that is resistant to mechanical and chemical influences. The treated surface can be glossy or matte. Gloss is the result of using varnish based on synthetic resins. The matte effect is achieved by acrylic coating on an aqua base.

MDF coating varnish is a two-component substance. Before starting work, you need to add a hardener to the base. Usually this varnish has no aroma.

The prepared working mixture must be applied within 2-3 hours. The coating can be applied using a sprayer or an ordinary brush.

Like all finishing materials, varnish for MDF panels has its advantages and disadvantages. In addition to the fact that it has good moisture and heat resistance, it protects the material from the formation of fungus and harmful microbes, creating a dense film on the surface of the slab. The varnished surface is easy to clean, does not wear out, and retains a good appearance for a long time. By covering a product, for example, a door, with a varnish composition, you can highlight the texture of the base and give it a certain color.

If the texture of a wood product needs to be hidden or given a different color, MDF is often painted.

The disadvantages of the varnish coating include its fire hazard, drying time, rather high cost and inflated consumption.

When choosing a varnish to coat MDF panels, you need to pay attention to certain characteristics:

• drying time does not have to exceed 72 hours;
• drying time from dust – no more than 15 minutes;
• operating temperature – from +5 to +25 degrees;
• the composition of the varnish must contain no more than 20% of volatile substances;
• consumption no more than 0.5 kg per square meter.

Results of sample size measurements.

Conclusions:

• Chipboard absorbs moisture most quickly and actively. MDF and solid wood are much more resistant to water.
• Swelling of MDF and chipboard continues even after the absence of water.
• After drying, MDF and chipboard practically do not decrease in volume, retaining residual swelling from water. The massif begins to more actively release moisture, its dimensions tend to the original ones, but the residual effect of water remains.
• Where the samples behaved identically when exposed to water was that none of the samples produced roots or young shoots.

Source: 5euro.ru

The working process

Before you start varnishing MDF structures, you need to prepare tools and additional materials:

1. Tassels. You will need 2 pieces. One (narrow), with which you can paint small parts, and the 2nd (medium) - for painting other parts. Candidate – roller or spray gun.
2. Container for mixing components.
3. A drill with a special attachment or a construction mixer.
4. Working capacity.
5. If there is a need to apply a sketch or ornament on the door, you need to prepare tape, stencils and a sponge.
6. Sandpaper.
7. Gloves.
8. Solvent.

It is better to cover the workspace with paper and prepare a stable door stand in advance.

Operating procedure

Before varnishing it is necessary to apply a layer of primer. For what? Firstly, the primer completely cleans the surface of dust and small debris. Secondly, it helps to avoid unnecessary consumption of the working consistency. Thirdly, it improves the absorption characteristics of the material. And, fourthly, it makes it possible to create the most uniform coloring. Also, thanks to the primer, you can find small damage to the door leaf.

The workflow consists of several steps:

• First you need to apply a layer of primer;
• use putty to cover small cracks, scratches and chips;
• walk over the surface of the doors with sandpaper;
• prime again;
• using a brush, apply varnish to the ends, stripes of the design and other awkward places;
• use a brush, roller or spray gun to paint the main part of the door;
• if necessary, apply a 2nd layer of varnish.

Aspects

1. You should not skip the surface preparation process, namely grinding.
2. Before work, the mixture of varnish and hardener must be filtered. It is better to apply the composition within 3 hours.
3. If a sprayer is used, the pressure must be 3 atm, and the nozzle size must be no more than 2 mm.
4. Any layer should be dried at a temperature of about 35°C. On average, the varnish dries in 5-6 hours.

Applying a varnish coating to MDF panels has many advantages. It increases strength and extends the life of the product. Varnish also plays a decorative function: it can make the surface matte or glossy and give it a suitable color.

Wall decoration

Wall decoration with clapboard

Wood, without a doubt, is one of the most popular materials for finishing the inside of balconies and loggias. Decorating the inside of balconies with wooden panels (most often clapboard) allows you to get a room that imitates a country house or terrace.

Balcony finishing with clapboard

Advantages of lining as a finishing material:

• Relatively low cost, at least for lining made from common types of wood . Oak lining from a domestic manufacturer or high-quality euro lining will naturally cost more.
• Environmental friendliness . Wood is a natural material, which is why wood paneling can be optimal for those who care about surrounding themselves only with safe materials.
• Durability . With proper processing and proper care, the finishing of the balcony from the lining will serve you for decades. And then you cover it with another layer of varnish….
• Good thermal insulation characteristics . Even if you do not take into account the insulation of the balcony, the wooden cladding itself retains heat much better than plastic or MDF cladding.

To ensure that the balcony wall does not have gaps and cracks, the lining panels must be fitted as tightly as possible to each other.

This is why eurolining is so popular today, as it ensures reliable connections between adjacent panels “in a lock”

Wall decoration with MDF panels

MDF panels are another material suitable for interior decoration of balconies. Unlike lining, MDF panels are a pressed wood-fiber mass, like very thick cardboard, covered on the outside with thick paper with a protective coating and a decorative pattern.

In appearance, it is quite difficult to distinguish a high-quality MDF panel from a board made of natural wood. At the same time, a variety of designs and colors of MDF panels will allow you to show your sense of artistic taste when developing a balcony design.

However, when decorating a balcony with MDF panels, you need to remember the following:

• MDF is far from the best heat insulator, so finishing the inside of balconies using MDF requires mandatory insulation . In this case, the insulation (see how to properly insulate a balcony) must be covered with a vapor barrier membrane.
• MDF panels are “afraid” of moisture, so the waterproofing of the balcony must be done very well, otherwise the MDF will swell and all the work will go down the drain. For the same reason, you should not use MDF for finishing unglazed balconies.

Wall decoration with plastic

In addition to lining and MDF, there is another option for interior decoration - covering the balcony with plastic panels. In this case, you can choose either traditional white plastic (such panels are the most inexpensive) or colored textured plastic.

In the second case, we will get a truly impressive result, because in terms of variety of textures and colors, plastic panels are not inferior to MDF.

Balcony cladding with plastic

When sheathing a balcony with plastic, you should fasten the plastic panels with some freedom.

This is due to the fact that plastic is extremely susceptible to temperature deformation, and in the cold it also becomes brittle.

Therefore, in severe frost, the plastic sheathing, rigidly fixed to the sheathing, can simply crack.