Studies were made of the depth of penetration into Scots pine sapwood/heartwood of the PVA adhesive Wikol with a 46% solid content with or without surface priming with Wikol at 10 or 38% solids or the urea formaldehyde resin U-70 at 50 or 58% solids. Average penetration was 0.1-0.3 millimeters into the unprimed wood; the best average penetration after priming was 2.5 millimeters for sapwood and 0.2-0.4 millimeters for heartwood using U-70 at 50% solids (100 parts by weight) with 30 parts of water and 10 parts of a 20% solution of NH* l4*sCl. Priming improves penetration and hence strength of glue joint. -- AATA