MDF stands for medium density fiberboard. MDF is a construction material made from millions of tiny wood fibers that are compressed together with glue to create a strong, durable board. It is popular for a range of uses, including construction, cabinetry, furniture construction and decoration. So can you stain and varnish MDF? The short answer is yes, but MDF does not have a grain in it as timber does and, therefore, will not have the same textured finish.
Choose Your Products
Seek out your local paint store and inquire about stain and varnish products for timber. These are usually used on wood products but also can be used on MDF. Stain comes in a range of colors to mimic the look of oak, maple, jarrah and many other species of timber. Look for a solvent-based stain to ensure even color coverage. Varnish is usually available in gloss or semi-gloss varieties. The color and gloss level you choose largely depends on the aesthetics of the project. If you plan to use your MDF outdoors, the varnish needs to be weather-resistant. Pick up a couple of small to medium-size paintbrushes and a drop-cloth while you're there.
A well-ventilated area is needed for this project, and protect your flooring using the drop-cloth. Give the surface of the MDF a light sanding using 100/120-grit sandpaper, including the edge faces. You may want to use a finer, 150/180-grit sandpaper if you have opted for a high-gloss finish. Brush the MDF surface with a plastic bristle brush and then a fabric rag to make sure it is completely free of dust.
Using a medium-size paintbrush, apply the stain to the surface in long, smooth strokes, making sure it is as even as possible with no drips or streaks. To mimic a grain affect, try overlapping each stroke with the next, both horizontally and vertically. Use the smaller paintbrush for smaller surface areas or hard-to-reach places. You may need two or three coats to achieve the desired color, especially if the stain soaks into the porous surface. Allow the stain to dry dry according to the time specified on the product label. Wash out your paintbrushes immediately after application to prevent them from sticking together.
When the stain is completely dry, it's time for the varnish. Again, apply the varnish to the surface with smooth strokes, making sure there is even coverage. You should need only one or two coats, with a light sanding in between. Let the varnish dry completely between coats. Again, wash your brushes immediately after use. Allow the varnish to dry completely before handling or using your MDF product to avoid fingerprints in the finish.