Do-it-yourself MDF painting technology and varieties of compositions, how to choose
Painting of MDF panels is carried out with special enamels intended for painting this wooden material. True, the durable surface of the plates allows you to use any paint and varnish products for painting, even car paints. The main thing is to sand and prime the panel with a primer for a fine porous base before painting. The result of the final coloring depends to a large extent on the correct primer.
Requirements for coloring compositions
MDF (Finely Dispersed Fraction) is nothing more than a fiberboard made from the smallest sawdust pressed under pressure and glued together. The surface of such panels used in the manufacture of furniture, for wall cladding, when laying floors, is flat and smooth.
MDF panels can be sawn, they do not crumble or break. The panels are very durable, hard and can be cleaned with water frequently. MDF panels are sold uncoated, with a laminated surface or covered with a film, varnished veneer or facing paper.Panels can be painted if desired.
The main thing is to correctly determine the type of initial MDF coating and select the corresponding paint and varnish material for the base.
Paint material requirements for painting MDF:
- do not destroy the original coating (film, varnished veneer or paper);
- lie down in an even, even layer;
- dry quickly after application;
- create a coating resistant to mechanical stress and abrasion;
- protect from moisture;
- do not change color for a long time.
You can paint MDF with paint and varnish over water and solvents. It is important to create ideal conditions for the paint to adhere to the panel coating. For this purpose, the finely porous MDF panels are lightly sanded beforehand and primed with highly effective primers.
The result of painting does not depend so much on the type of paint, but on the method of applying the painting materials to the surface and the correct primer. MDF panels are best painted with a paint sprayer. Such a tool will help to create a perfectly even and thin coating. For priming the slabs, a special primer for finely porous surfaces is suitable. The main thing when working with painting materials is to paint only clean, grease-free and absolutely clean boards.
Which paint is right
Any paint (water-based or solvent-based) is suitable for painting MDF. It is important to pretreat the slabs with a primer and apply the paint materials once or twice in a thin layer. It is recommended to paint the panels horizontally.
Enamels
Alkyd, acrylic, nitrocellulose, polyurethane enamels based on solvents and with resins in the composition create a durable, moisture-resistant and glossy surface.Apply by brush, roller and spray. Their main characteristic is that they dry quickly.
Based on polyurethane resins
Paints and varnishes based on polyurethane resins are produced in two types: on organic solvents and in the form of an aqueous dispersion. In both cases, these paints contain polyurethane. It is this component that gives strength and moisture resistance to paint materials.
acrylic enamels
For painting MDF, solvent-dilutable acrylic enamels are used. For painting furniture, special paints and varnishes on acrylic with a gold, silver and bronze sheen are produced. These decorative paints dry quickly. They are applied using a roller, paint sprayer. After drying, they form a hard film. The color of the coating is retained for a long time.
Nitro Paints
Nitrocellulose enamels are paint materials based on nitrocellulose, alkyd resins and solvents. After drying, they give a beautiful shine and a durable film. Nitro enamels do not deform the MDF coating, they adapt well to the base.
Two-component polyurethane enamels
It is a paint material consisting of two components - a semi-finished product with resin and a semi-finished product with a hardener. It is recommended to mix the two parts before painting. The mixture obtained has a very short pot life. It is necessary to apply the paint to the base within 1-3 hours. The mixture hardens in the open air as a result of a chemical reaction that occurs after mixing two components of paint materials.
Special enamels for MDF
Manufacturers of paint materials produce special enamels for painting MDF. The most popular: acrylic, polyurethane, alkyd. Such paint materials do not deform the coating of MDF panels, dry quickly, create an even layer when applied with a paint sprayer.
Automotive enamels
For painting MDF panels, you can use car paints, which give the surface a glossy shine. Varieties: nitro enamels, alkyds, acrylic enamels, hammer effect paint materials. Car enamels are intended for metal, but can be used for smooth MDF panels.
What you need to paint
In addition to paints and varnishes, it is recommended to purchase tools (rollers, brushes, spray gun) and a primer for painting MDF panels. To prepare the paint, you will need fine sandpaper. You also need to buy a special thinner to dilute the paint. The type of thinner is indicated in the instructions or on the paint label.
For painting MDF, it is recommended to use a high-quality and very effective primer. The adhesion of the paint to the plate depends on this tool.To prime a fine-pored base, an alkyd, polyurethane, polyester primer is usually used. As a rule, it is a transparent liquid specially designed for the treatment of veneers, laminates and MDF panels before painting. The primer is applied to the surface by spraying and dries quickly (in 1-3 hours). True, grinding after applying the primer can be carried out no earlier than after 4 p.m.
How to properly prepare the surface with your own hands
Before painting MDF panels, it is necessary to sand them. Plates are sanded with P220 grit and finer. The main thing is not to remove the coating, but to slightly roughen the surface. A smooth, glossy painting should become matt.
The surface is first degreased (with acetone, solvent), then sanded, primed, then lightly sanded again. It is important to sand and dirty all parts of the slab. The grinding process is generally simple.If the film was initially poorly adhered (in case of violation of the bonding technology by the manufacturer), then after sanding it can peel off.
It is advisable not to rub the surface strongly during grinding. It is recommended to prime the MDF with a very thin coat of primer (spray). The faster the floor dries, the less likely the coating is to deteriorate. It is better to prime the MDF twice with the thinnest coat of primer than to pour the slabs with a liquid agent and wait for evaporation.
Dye technology
MDF panels are painted with a thin layer of paint two or three times. Before applying paint materials, the surface should be degreased (wiped with acetone or solvent), primed and sanded. After painting, the front of the furniture can be varnished. True, varnishing of MDF panels should be carried out no earlier than 30 days after painting.
The paint dries quickly, but the curing process is slower. Usually the paint layer hardens within a month.
The main stages of painting MDF panels:
- cleaning of dust and dirt;
- degreasing, removing oil stains with acetone or solvent;
- grinding with fine-grained sandpaper;
- treatment with a primer for a finely porous base;
- dry the surface for 24 hours;
- finish grinding;
- coloring;
- application after 30 days of varnish.
Padding
Before painting, MDF panels must be primed with a special primer for fine-pored surfaces. It is recommended to grind the plates first. After applying the spray primer, after one day, it is advisable to lightly sand the MDF again.It is important to remember that the final result of staining depends on the correctly selected soil. If the boards are not primed, the paint will simply drip off them.
Coloring
Painting of MDF panels is carried out using a short-haired (foam) roller or spray. A smoother, more even coating gives the use of a spray gun. It is necessary to paint the plates in a horizontal position, in wide straight strips (across the length). The painting is carried out in 2 or 3 layers. It is forbidden to fill the panels with paint. The coat of paint should be very thin. In the process of painting, respect the interval between the coats to dry the paint.
Finishing and varnishing
At the finishing stage (one month after painting), the MDF surface can be varnished. It is recommended to use a type of varnish compatible with paint. You cannot paint MDF, but polish immediately. Previously, the surface will need to be sanded and primed. Polishing the panels will help create the roughness needed for any paint to adhere.
It is not recommended to use oil varnishes. They dry longer and are only used for natural wood. Varnishes are applied to the surface using flat brushes, velvet rollers or a spray gun.
Solve common problems
Possible problems and methods to solve them:
- if the surface is “washed away” after painting, it means that the paint was applied to a wet substrate (before painting, the MDF panel must be well dried);
- if the coat of paint is irregular, it means that the panels have not been cleaned of oil stains (the bottom must first be degreased with acetone);
- if the paint does not adhere to the surface, it means that the MDF has not been sanded or primed (before painting, you must sand and prime the plates).
Additional tips and tricks
Some useful tips for painting MDF:
- it is important to choose the right tool for staining, the final result will depend on its quality;
- for an even application of varnish or paint, it is best to use a spray gun;
- you must work with any type of paint in a respirator;
- it is recommended to carry out the painting work in a perfectly clean room;
- the optimum temperature for painting panels is 20-25 degrees Celsius;
- you need to grind MDF panels with light, smooth movements so as not to damage the coating;
- when using powder paint, it is recommended to prime the surface with a primer based on electrically conductive substances;
- after applying the first coat of paint materials, the surface can be lightly sanded, then another coat of paint or varnish can be applied.