M. Hameed et E. Roffael, On the wettability of sapwood and heartwood of various woodspecies (Pine, Douglas fir and Larch), HOLZ ROH WE, 57(4), 1999, pp. 287-293
Results have established that the wettability of sapwood from three woodspe
cies (Pine, Douglas fir and Larch) on the cross, radial and tangential sect
ion with water and various glues (UF-resins, PF-resins, MUPF-resins and PMD
I-adhesive) is better than that of heartwood. In most cases, the tangential
section in sapwood and heartwood was less wettable than radial and cross s
ections. Using alkaline phenolic resins which cause wood to swell, wettabil
ity in the tangential direction was improved.