The Key to a Perfect Wood Finish: Understanding Fillers

The first step to achieving a superb finish on your woodworking projects is recognizing that not all hardwoods are created equal. Many woodworkers know this instinctively, but comparing a piece of red oak to a piece of cherry illustrates the differences clearly. Look at the surfaces head-on and at an angle. Red oak has large, open pores that need filling for a smooth finish, while cherry has a tighter grain that looks fantastic with just a few coats of finish.

Open-Pored vs. Closed-Pored Woods

Red oak is an open-pored wood, technically called “ring-porous,” with visible openings across its surface. Other open-pored woods include walnut, butternut, black locust, mahogany, rosewood, catalpa, ash, hickory, and pecan. Without fillers, these woods can create challenges. For instance, writing on an unfilled red oak desk might leave notes punctured by the pores.

In contrast, woods like cherry and maple have smaller, less noticeable pores. These “closed-pored” woods don’t…