Jointing is a technique to obtain the same cutting circle for all knives mounted in a cutterhead of a peripheral knife planer. Initially the jointed land at the cutting edge has a 0 degree clearance angle that becomes negative with workpiece motion relative to the cutterhead and as the cutting edge wears. Jointed knives may crush cells on the planed surface and affect the quality and performance of wood for end uses. We evaluated the gluing properties of northern red oak planed surfaces that had been planed using one of three jointed land widths, over four levels of knife wear. Under these cutting conditions, surface roughness significantly influenced gluability more than cellular damage. In sum, gluing performance was positively affected by knife wear, and no variation in gluing performance among the jointed land widths studied existed. In samples after accelerated aging, the effects of wear on gluing were more pronounced, with an improvement in gluing performance, associated with an increase in surface roughness and permeability with increased knife wear. These results suggest a jointed land of 1.2 mm as the maximum allowable width for planing red oak wood prior to gluing. Also, the planed surface gluability of this wood may be enhanced using a knife with the rake face recession of 332 μm and the clearance face recession of 438 μm, which results in a surface roughness of 40 μm Rmax
