Great Glue-Ups, Guaranteed
The secret is cauls, and lots of them
Synopsis: Glue up panels, edging, joinery, and casework with maximum success and a minimum of stress. Michael Fortune’s formula for successful glue-ups starts with remembering that glue is a slippery film. Once it is applied and clamps are tightened, everything wants to slide. Your mission is to keep that from happening, and the way you do it is with the right combination of cauls and clamping force. Learn this pro’s secrets to great glue-ups, every time.
When assembling furniture parts, there is one rule I always remember: glue is a slippery film. once it is applied and clamps are tightened, everything wants to slide. restraining those parts—holding them in perfect position—is just one reason that I use clamping cauls. Cauls are simply extra pieces of wood, usually wrapped with tape or coated with wax to resist glue, held in place with additional clamps.
In this slippery situation, the direction of the clamping force is critical. So I choose and position clamps so that their force will pass through the center of the joint, and at right angles to it.
As a pro woodworker, I can’t afford to invest hours of time making perfect parts only to end up with gappy joints, crooked assemblies, or bumpy tabletops that require a lot of planing or sanding. And with the right clamps and cauls, I don’t have to.
For a full rundown of the glue, clamps, and cauls I’ve come to rely on over the years, turn to Fundamentals on p. 22. In general, I use Titebond III, because of its longer working time, and low-tech F-style clamps and pipe clamps. Their small jaws let me know exactly where I am applying force. As for cauls, I generally make them from hardwood and apply clear packing tape…