How to ensure snug-fitting dowels
Dowels can run a few thousandths of an inch larger or smaller than their specified diameter, leaving them tight or loose in the mating holes. Here's an easy way to make sure that the dowels fit snug. For a 1⁄4 " dowel, for example, drill a 1⁄4 " hole in scrap. Test-fit the dowel in the hole. If tight, chuck a maximum 6"-long piece of dowel in your drill. Turn the drill on, and sand the dowel evenly along the length, as shown, until you achieve the desired fit. If loose, drill a 15⁄64 " hole (1⁄64 " smaller in diameter) in the scrap. Check the fit of the dowel in this hole. If snug, drill 15⁄64 " holes in the workpiece. If tight, sand the dowel, as before.