Avoid assembly disasters and achieve superior glue joints every time by matching the glue to the application.
A good glue joint is usually stronger than the wood being joined. In other words, it’s more likely the wood will break before the glued joint fails.
To achieve these results, you need to use the right glue for each application. Here’s a look at the most popular glues and when each should be used.
The most common wood glue, polyvinyl acetate (PVA) glue, is perfect for basic woodworking projects. It’s inexpensive, non-toxic and cleans up with water. Its modest tack allows you to reposition workpieces during assembly, but once cured, the glue is very strong.
Some PVA glues are waterproof, some cure slowly (allowing more time to fit pieces together), some are thicker in order to eliminate drips on vertical glue-ups. There’s even a dark version for gluing dark woods like walnut.
Epoxy is made of two thick, liquid ingredients: resin and hardener. When these ingredients are combined, a chemical reaction causes the epoxy to harden. Epoxy is waterproof and does an excellent job filling gaps. (Most other glues will not bond effectively if there is a gap between the pieces of wood being glued.) Some epoxy glues cure slowly, while others cure in under five minutes. Usually, the longer it takes for the epoxy to cure, the stronger the bond.
Polyurethane glue, aka Gorilla Glue, is weather-proof, making it well suited for outdoor projects. Besides Gorilla Glue, there are other excellent polyurethane glues available. In addition to wood, this glue bonds well with plastic, stone, metal and fabric. As it cures, it tends to expand and ooze. Since the glue is hard to remove, quickly clean up any glue that’s oozed out.
Cyanoacrylate (CA) glue, often referred to as “super glue,” is the go-to glue for small repairs. It adheres to virtually any material. And because it sets instantly to form a stiff, plastic-like bond, it is perfect for gluing tough-to-clamp items such as small plastic parts, jewelry and porcelain. CA glue comes as a liquid and as a gel that can eliminate messy runs.