ASSEMBLING AND GLUING

In the production of furniture, significant shop space is required for assembling and gluing pieces together. Clean, flat, work surfaces are needed to glue and clamp material together.

Подпись: Figure 8.14 Shop clamps are essential for gluing assembly work. Photography by Jim Postell, 1994. Assembling furniture is a complex process that needs to be planned carefully. In addition to needing a lot of space, this phase requires a significant amount of time, primarily the set time required for the carpenter’s glue to set and fully dry. Most PVA glues allow 30 minutes as an open time to work with and require approximately 1 to 1/ hours to set before one can remove the clamps (Figure 8.14). (Timers can make the process of assembly more efficient.)

Many types of adhesives are used in making furniture. PVA is the woodworker’s glue of choice and comes as white glue, yellow glue, or exterior-grade waterproof yel­low glue. As a rule, let the glue do its job. Put no more glue than is needed on each surface to create a uniform bond. When gluing wood together, both sides should receive a continuous application and should sit for a few minutes before one proceeds with assembling and clamping. This allows the glue to soak into the wood and will increase the strength of the joint. Remember not to overtighten a glued assembly because it will squeeze out the adhesive and reduce the strength of the bond. Further, remember to vent all blind holes that will be glued; otherwise, problems will result during finishing when you try to wipe glue off unfinished wood.

Applying glue to the end grain of wood will always pro­duce an ineffective joint and should be avoided. The strength of any glue joint is proportional to the perimeter length of the joint, since the perimeter is the most highly stressed area.

Epoxy resins are useful for joining different materials together and are ideal for exterior work because they are waterproof.

Contact adhesives are available in solvent and water based. These adhesives are applied to both surfaces, left until tacky, and then bonded together under the continuous pressure of a hand or machine roller. When laminating a substrate, it is important to laminate the back side so that the finished panel does not warp or twist.

Cyanoacrylates are instant glues that typically cure in 5 to 10 seconds.

Silicone is an adhesive caulk that can be used to bond materials that expand or contract very differently from one another, such as wood and glass or wood and metal, because sili­cone remains flexible when fully cured. Silicone is little affected by temperature or moisture and works well for interior and exterior uses. It requires 24 to 48 hours to fully cure.