Below are suggested adhesive guidelines for achieving optimal results in hot or cold press lamination applications. Consult your supplier for specifics.

Spread: Generally, 35-45 pounds of adhesive per 1,000 square feet or 170-220glm² of glue line is adequate. Lower spread rates require closer stock tolerances and shorter assembly times. Commonly, a mechanical glue spreader is used to apply a uniform spread to the gluing surfaces.

Assembly time: Assembly time can vary greatly depending on the adhesive used, glue spread, porosity, and moisture content of stock, environmental conditions, etc. A small bead of adhesive squeeze-out around the perimeter of the bottom panel in the stack is desirable. Generally accepted assembly times range from five to 20 minutes at room temperature – assembly time should be kept at a minimum. It’s recommended to glue the veneer with the tight side out.

Tolerances: Gluing stock should be uniform in thickness. Variation in thickness should not exceed ±0.005 inches or ±0.125 mm. Sanding to thickness should be performed using higher than 50-grit abrasives. Tight-cut veneer is recommended. Panels should not be over-sanded, especially to the point of exposing lathe checks.

Pressure: Pressure is dependent upon the species or material to be glued and the joint preparation. Direct contact of the gluing surfaces must be made to obtain maximum strength. 

Suggested pressures for various wood densities in a hot press are: low 100-150 psi or 2.1-5.6 kglcm²; medium 125-175 psi or 7.0-10.5 kglcm²; high 175-250 psi or 7.0-17.6 kglcm². 

Suggested pressures for various substrates in a cold press are: high-pressure laminates, 30-80 psi or 2.1-5.6 kglcm²; solid core stock, 100-150 psi or 7.0-10.5 kglcm²; all-veneer constructions, 100-250 psi or 7.0-17.5 kglcm².

Source: Franklin Adhesives & Polymers. For information call 800-877-4583 or visit FranklinAP.com.