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Slow-Set Glue

Complex glueups, involving lots of parts and lots of clamps, can be tough and stressful. The challenge is to get the glue spread, the joints assembled, and the clamps in place and tightened down before the glue starts to tack up and "grab."

Most yellow glues only give you about five to ten minutes "open time" to get all this accomplished. And often this isn't enough. The new, slower-setting Extend PVA glue, shown at right, offers you a fighting chance. Its slightly longer open time gives you a few extra minutes to get the job done (photo above).

When it comes to "yellow glue," woodworkers now have a lot of choices.

When you hear a woodworker talk about using glue, it's a pretty good bet they mean PVA (polyvinyl acetate) glue. This is the common yellow (or white) glue that most of us rely on for ninety percent or more of our gluing chores. For most woodworking applications, it just can't be beat.

But in recent years, new types of PVA glue have been showing up that make it even more useful and versatile. And I won't argue with making a good thing even better.

Gap-Filling Glue

A Tighter Joint Box

joints or dovetails assembled with gap-filling PVA glue might look a little better.

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Gap-filling PVA glue needs a little explanation. It might not be quite what you think it is. You don't want to think of so-called "gap-filling" PVA glue as a cure for poor-fitting joinery. But where it does have a place is in making your joinery look better and saving you some time.

The fact is that most PVA glues are more than half water. When the water evaporates and the glue cures, what's left are the bonding resins and fillers. The key to gap-filling glues is that they contain a little less water and have a slightly higher solid content. What this means is that these glues shrink a little less when they dry.

This feature can come in handy when gluing up exposed joinery like dovetails or box joints (photo at left). The extra volume left after the glue dries acts like a filler to help close the inevitable small gaps in the joinery. But remember, it's just for looks, not strength.

38 ShopNotes No. 86

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