Will glue fill gaps caused by undersized dowels?
I found some 3⁄8 " dowel stock that turned out to be as much as 1⁄64 " undersize. How much clearance will glue fill? How loose is too loose?
—Robert Vawter, Spokane, Wash.
Water-based wood glues make poor gap fillers, Robert, because they can leave tiny voids as the water in them evaporates. Proper fit means the dowel can be inserted with finger pressure or a light tap, according to Dale Zimmerman, technical specialist for Franklin International, makers of the Titebond line of glues. The dowel should not fall out of the hole if the joint is turned upside down. Where undersize dowels make gaps unavoidable, use epoxy glue that doesn't leave voids as it cures. Drilling a smaller diameter hole may also solve your problem.