Seal the perimeters with drywall putty to confirm an even coat once painting medium density fibreboard.
For any painted cupboards, furniture, wall panelling and a few moulding, MDF is an excellent selection of fabric. Surface faces return from the plant sanded to one hundred fifty grit or higher, primarily paint-ready.
Scuff-sand the surface quickly with 120-grit or 150-grit sandpaper to get rid of any dirt and dirt and to produce for higher adhesion of the ground.
Always use a solvent-based primer
Solvent-based primers (oil-, alcohol- or lacquer-based) area unit a requirement. ne’er use a water-based product for the initial end coat. The wood fibres can swell an excessive amount of once they absorb the water and you may get raised grain on the surface which will not sand out.
After the surface has been sealed with one thing else, a water-based paint won’t have an effect on the MDF adversely. Use water-base paint over properly sealed wall panelling and trim moulding. For a painted piece of furniture or cupboards, the end quality of oil- or lacquer-based paint that’s applied with a spray gun is way higher.
Preparing porous edges
The only real problem that arises once painting MDF is what to try to regarding the perimeters, that area unit additional porous than the surface — kind of like the tip grain of lumber — and soak up most of the end. There area unit some woodworkers World Health Organization move to the difficulty of edge-banding the MDF. That approach takes longer than the choice, and in spite of however well the edge-banding has been applied and cut, a seam still might show at the terrible edge.
The alternative technique is to use drywall compound to fill the perimeters, whether or not they area unit cut squarely or formed with a router bit and apply the compound munificently with a finger or with the palm of your hand. not like spackling compound or typical wood putties, drywall compound incorporates a soupy texture, thus it is a very little sloppy happening however once it dries it’ll sand off simply.
For edges formed with a router, you’ll use a similar router bit like a hand tool to get rid of the surplus globs of a compound, before touching up the perimeters with 220-grit silicon carbide sandpaper.