Next to the wood itself, glue is the most important building material in your shop. Though you rarely should see the glue in a well-built project, it has a lot to do with how professional that project looks . . . how well it performs...and how long it lasts.
A rugged, long-lasting glue bond depends on four primary factors:
1. The type of glue you use
2. The fit of your joint
3. The surface areas you’re gluing together
4. The preparation of those surface areas
Choosing the right glue for the job
All glues work pretty much the same way, holding materials together by surface attraction. On wood, the glue grabs onto the wood grains like little fingers to bond the pieces together. But, this is where all similarities end.
There are dozens of glues available to the woodworker, each with different properties that make it more suitable for one application or another. For example, yellow aliphatic resin glues (the most common of the woodworker’s glues) comes ready-to-use. Others, such as resorcinols or epoxies are multiple-part glues that must be mixed prior to application. Some are waterproof, while others will actually dissolve in water. Some take hours to dry while others dry in seconds.
When the time comes for you to select the glue you’re going to use, you’ll need to consider all the things that glue will have to do for you. Does it need to be waterproof? Can it be sanded and machined? Will it react with the finish you’re using? Will it stain your wood? Is it strong enough? Will it dry too quickly to allow you enough open time for assembly?
Be sure the glue you’re planning to use meets all your needs...then follow the manufacturer’s directions explicitly to get the best bond. Even the most strongest, most tenacious glue won’t hold if it’s applied incorrectly.