Mediumweight panels (or MDF) are very often used in interior design (worktops, cupboards, furniture, etc.). In this article, we will present the advantages and disadvantages of medium wood. Then we will advise you on how to protect MDF, as there are different finishes for medium wood, varnishes and paints being the most common. We will present you with the optimal finishes for waterproofing MDF medium.
The medium (also known as MDF from medium density fiberboard) is in the form of wood fibreboard.
The surface of the medium is smooth and uniform. In contrast to pure wood, you will not see any veining on the medium.
The wood used to make medium panels can come from different species (wood, hardwood, softwood, etc.) reduced to chips (fibres). Fibres that are too fine and too large are removed. The remaining wood fibres are then bonded together with resins using heat and pressure techniques.
Some species used in the manufacture of MDF panels do not resist well to external aggressions. Chemical substances can be added to make the medium resistant to mould, fungi or moisture.
This type of wood is often found in interior design (MDF worktops). Its main advantage remains its lower cost compared to solid wood.
Medium wood is widely used in woodworking. Indeed, it is very easy to cut and allows to realize very accomplished creations with basic tools. This material is ideal for starting out in woodworking. We advise you to take precautions (wear a mask) because some resins used in the processing of mdf can emit harmful substances during cutting which create dust. There are resins with low toxic substances for making medium panels. We recommend that you enquire with the manufacturer.
The fibres of the medium are not very resistant to moisture, which is why certain chemicals are added during the manufacturing process to increase the water resistance of the medium wood. However, even after the addition of these substances, the medium wood does not have optimum moisture resistance. We recommend that you protect MDF medium wood if it is in a damp room such as a kitchen or bathroom in order to prevent warping. The main purpose of protection is to waterproof the MDF.
Medium panels may contain chemical substances. It is recommended to inquire before purchase.
It is possible to varnish MDF. In order to be satisfied with the result, it is important to follow a few tips.
To obtain a quality finish on MDF, we advise you to apply a primer for MDF and other woods before varnishing. The medium is very porous and absorbs a lot of protective products. If you wish to apply a varnish on medium wood without a primer, MDF will tend to consume a lot of varnish, which will cost you more.
In order to apply the primer in ideal conditions, we recommend using the product in dry weather, the aim being to avoid wet weather in order to achieve quality work and avoid distortion of the medium. Within our range, we recommend the Pore Filler Primer BP400.
Varnishing the medium is very simple. Simply use a varnish for MDF wood and apply it in 2 to 3 coats with a brush or roller in the direction of the wood fibres.
After the first coat of varnish for MDF, lightly grit the surface with 120 grit in order to obtain a perfectly smooth surface. The ginning will allow you to eliminate any roughness, air bubbles that may appear during the application of the first coat of varnish.
Within the Anova Wood range, you can use different finishes for MDF furniture : the Furniture Varnish VM500 or the Worktop Varnish VPT500. If you wish to protect the MDF from water, we recommend Worktop Varnish VPT500, which contains a reinforced protection against water. These two clear varnishes for MDF and other woods do not alter the colour of the medium.
However, if you prefer a coloured finish, you can opt for our Colour Wood Varnish VBC500. Like the clear varnishes, it protects the MDF against moisture.
MDF wood can be painted. As with varnish, we recommend applying an undercoat for MDF and other woods such as Pore Filler Primer BP400 to adapt to the porosity of the substrate. Painting MDF without an undercoat could give a disappointing result.
Begin by lightly gritting the surface with a 100 or 120 grit. This step increases the adhesion of the medium. Then degrease the surface with methylated spirits or acetone.
Once this has been done, apply the primer for MDF. Pay particular attention to the edges, which are very porous.
Then apply a paint for MDF and other woods such as Interior Wood Paint PBI900. The paint will make the medium waterproof, which is very useful for a kitchen cabinet for example. We advise you to paint both sides of the medium to avoid deformations. When MDF is painted only on one side, it tends to bend.
Painting for medium and other woods will protect the medium from water. However, varnish will be the product with the best water repellent function for MDF.
We advise you to always test the products presented beforehand on a small area or medium drop.