Use the Right Glue

Like a saw blade or a chisel, adhesives are tools, so the “right” one often depends on the circumstances or materials involved. Still, there are some basic guidelines that apply. Let’s look at glue for outdoor woodworking projects.

First, don’t rely on conventional white (polyvinyl acetate, or PVA) or yellow (aliphatic resin) woodworking glues that aren’t specifically labeled as “weatherproof,’ “waterproof,” or otherwise intended for exterior use.

It’s unlikely that your projects will ever experience stresses as extreme as the test procedures used to rate exterior glues, which can involve repeated cycles of water saturation, boiling, and oven-drying. But these tests help define useful labeling standards. For example, a Type II adhesive such as Titebond II Premium is considered a “weatherproof” glue appropriate for outdoor furniture and similar projects but not for load-bearing structural applications such as large glue laminated beams.

Titebond III Ultimate is labeled “waterproof” because it has passed more stringent requirements for a Type I rating, though it too is not recommended for load-bearing structural assemblies or for below-the-waterline marine use or other submerged applications.

Polyurethane glue adds a little more versatility because it is a waterproof woodworking glue that also bonds non-porous materials such as metal and plastics, so if your projects feature mixed materials this is a good option.

For extreme applications or load-bearing structural use, you would probably have to rely on specialized two-part industrial adhesives such as phenol resorcinol or various epoxies, which require mixing and sometimes careful handling because of their strength and toxicity.