What's the Difference: Exterior Glues
Higher strength, lower cost, and higher resistance to the elements make Titebond III the obvious glue of choice--but only if you're working with wood
Like most carpenters, I started using polyurethane glue for exterior trim work because it’s 100% waterproof. But I’ve never liked working with the stuff. Polyurethane glue foams and expands as it cures, so mating parts need to be clamped for a few hours until the glue sets. Otherwise, the foaming action can push the joint apart.
Applying the right amount of polyurethane glue takes experience. Some should squeeze out after the glue cures, but excessive dried glue is a pain to scrape off. Skin contact also is a problem. I have to wear latex gloves whenever I use the glue because if it gets on skin, it can cause a sticky stain, or worse, serious irritation. Still, the payoff is worth the hassle: durable joints that I’m confident will hold up.
When Titebond III hit the market, it changed the whole playing field. Hailed as the first waterproof…