What are special considerations for painting on MDF?

Some special considerations for painting on medium-density fiberboard include priming, sanding, ensuring a dust-free board and finishing the porous edges. While painting MDF, the paint may dry quickly in an uneven and blotchy manner. Therefore, apply a layer of MDF primer first to allow other paints to dry uniformly.

Painting a moist MDF surface may cause bubbles, crack or lift. The surface of the MDF should be dust-free, smooth and flat. The edges of the MDF absorb more paint than the surface and a thin layer of wood filler should be applied to the edges, then sanded using a sanding block to avoid overabsorption of paint.