How to seal and spray or paint the edges of the wood.
By Bob Vila
Both furniture and home construction use Medium Density Fiberboard.The engineered wood material can be found in 4' 8' sheets and smaller project-sized boards ranging from 1/2” to 1” thick.
Unlike plywood, which is made from many thin sheets of wood veneer, MDF is free of knots, rings, and grain.The result?A composition that is very easy to cut and is often used for upscale applications.Its smooth surface takes veneer and paint very well.
It takes an understanding of the material, which comes from the factory sanded to a 150-grit smoothness, so the face is ready to paint, but the edges are more porous, and require some prep for a smooth, uniform finish.The material is unsuited to water-based products for the initial coat.If you follow the guidelines, your project will turn out great.
If working on a piece of furniture, remove any hardware and set it aside until the paint has dried.Drop cloths can be used to protect the work area.If you work with MDF, be sure to wear protective eyewear and a dust mask because of the fine particles that can irritate eyes and lungs.
The edges of your project must be sealed to accept paint in a way that matches the smooth face of the material.You can seal the edges by running a coat of compound over them.Sand the edges with 220-grit sandpaper after it has dried.Any mars or scratches on the face of the MDF will be obvious once painted, so fill them with drywall compound as well.Sand the entire piece with 220-grit sandpaper, then wipe it all down with tack cloth to remove any remaining dirt or debris.
You can buy a solvent-based primer for the MDF.Water-based primer may cause the wood fibers to swell, resulting in a surface that appears to have a raised grain, no matter how much effort you put into sanding.The primer should be applied with a brush, roller, or spray gun.
You can apply the paint finish with your preferred method, be it a brush, roller, or spray gun, it's up to you.If the first coat of paint feels dry to the touch, it's time for a second coat.If you notice patches, cover the entire project with another coat of paint.