At
FDM/Cabinetmaker magazine, we recently had an interesting question in our
Wood Dr. column by Gene Wengert about how freshly prepared surfaces make stronger joints.
Q. In your many helpful suggestions on gluing, you indicate that freshly prepared surfaces make stronger joints. Why is that?
A. You are indeed correct. We often will find that a surface prepared and then glued within minutes will make a stronger joint. There are two main reasons.
First, the wood surfaces are flatter, meaning more of the two mating surfaces will be 0.002 to 0.006 inch apart (the ideal for most adhesives). They are flatter because there has been no chance for moisture changes that will cause size changes and warping on a microscopic level.
Second, the surfaces are more chemically reactive (can react and bond better with the adhesive) because there is no outside contamination (like dust or moisture) and there is no contamination from inside the wood (like resin moving to the surface).
Gene explains that wood surfaces that are flatter will glue better, and surfaces that are more chemically reactive (no chance for outside contamination) will offer a better surface for gluing.
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