An improved apparatus is provided for curing powdered coatings on the face of porous wood products, such as medium density fiberboard (MDF), wherein a pair of inclined infrared catalytic heaters are used to apply heat directly onto the side edges of the board. In addition, catalytic heaters that are normally used to heat and cure the face surface of the board are moved father back to reduce their effectiveness and to limit out-gassing of entrapped air from the inner low density core of the board. This arrangement also allows the coating to cure at the side edges of the board at approximately the same rate as the face of the board, promoting a more uniform curing of the powder coating.