Woodworking Adhesives: Methods & Myths for Good Gluing
April 2, 2015 | 2:17 pm CDT

Four adhesive methods for gluing wood and panels are identified in this informative report. Also of interest are the myths that get revealed. Check them out:

1 Adhesive Method: Serious veneer checking can be greatly reduced by controlling the manufacturing techniques during panel production. The more important factors which affect the degree of checking in face veneers are veneer species, type, thickness and moisture content, as well as, type of core material and construction methods.

2 Adhesive Method: When fingerjointing, be careful to avoid “hydraulic” spring back of fingers. This can occur in two ways. First, spring back can occur when too much adhesive is applied. Second, it happens when insufficient clearance is allowed at the base of the fingers to accommodate the adhesive.

3 Adhesive Method: To determine the correct pressure to use when edge gluing or panel pressing, look for a thin, uniform bead of squeeze out at all points. Copious amounts of squeeze out indicate too much adhesive or too much pressure. Conversely, no squeeze out indicates too little adhesive, insufficient pressure, or uneven joints.

4 Adhesive Method: The key to good, thin, nearly invisible spline lines is precise control of adhesive spread. Applying too much adhesive will squeeze out on the veneer surface, and appears as a thick splice line which is very visible. The new precision roller applicators are superior to spray application in controlling adhesive spread. 

5 Adhesive Myth: Aliphatic resins are better adhesives than regular PVA’s. The therm “aliphatic” refers to a particular chemical group that includes PVA polymers. Just as all baseball players are athletes, but not all athletes are baseball players, all PVAs are “aliphatic,” but not all aliphatics are PVAs. Consequently, again, its important to evaluate the working and bonding characteristics of an adhesive.

6 Adhesive Myth: “Yellow glue” is better than “white glue.” While there are a large range of PVAs with varying working and bonding characteristics, these characteristics are not related to the color of an adhesive. A particular yellow glue typically begins as a white glue with yellow dye added to it. When deciding on an adhesive evaluate its bonding characteristics rather than its color.

Source: Spectrum Adhesives/CP Adhesives. For more information call (800) 454-4583 or visit CPAdhesives.com.


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