Wood is a natural material that is used for many structural and construction purposes, as well as for furniture, trims for other substrates, boats, and other purposes. Using adhesives to bond wood to itself provides many benefits over using fasteners, nails or screws. Among the benefits are that loads can be more evenly distributed throughout the structure by use of adhesives when compared with mechanical fasteners. This allows the structure to be built using less material to achieve the same strength and reduces material costs. Bonding wood is different than bonding other types of substrates in general because the objective of bonding wood is to create joints which are stronger than the wood itself. Epoxy resin adhesives can form joints with much less strict conditions than required to use other types of adhesives and with bond strength exceeding the shear strength of almost all woods. In addition, many of these other types of adhesives contain significantly more hazardous chemicals than epoxy resins, such as phenol-formaldehyde, resorcinol or urea-formaldehyde. Epoxy resin adhesives, in particular, provide great bond strength throughout the moisture range presented by wood from newly cut through kiln-dried and are unimpacted by moisture both during and post-cure. Other kinds of adhesives require moisture to cure, as high as 18%, but kiln dried lumber contains less than 8% moisture. An additional advantage in using epoxies is that clamping or pressure are not required to achieve a good bond and less well prepared surfaces are readily bonded, also reducing costs. Also epoxy adhesives generally shrink less than other kinds of adhesives, reducing unanticipated movement during cure and less requirement to backfill cavities left by shrinkage.

In addition to being bonded to itself, wood is frequently attached to other substrates. Using adhesives for this purpose requires that the adhesive address the coefficient-of-expansion (COE) of each material and remain flexible enough to withstand temperature cycling of the materials and resist environmental degradation from moisture and chemicals. BONDiT^TM epoxy products are among the few available that can be used to bond wood to substrates with other COE's for long term deployment.

Our highest recommended product for this purpose is BONDiT^TM B-45TH or B-482TH. The TH stands for thixotropic, which allows the adhesive to be applied in most vertical applications without sagging or running during the cure cycle.

Our recommendation would change if a fast cure is needed in which case we recommend BONDiT^TM B-536TH.

If you are looking for a hard clearcoat and sealer for wood, we recommend BONDiT^TM B-481.

Among the other substrates which wood can be bonded to using BONDiT products are: UHMW, Delrin, fluoropolymers, copolymers, TPE / TPR, polyethylene, polyolefin, polypropylene, polyurethane, silicone, rubber, thermoplastics, thermoset, urethane, ceramics, glass, fiberglass, metals, stone, aggregate and concrete.

To see our chart showing elongation rankings of the various BONDiT products click here. Call or email us for advice on for COE ratings and matching BONDiT products for your application at (707) 284-8808 or reltek@reltekllc.com.