How to Seal Kitchen Cabinets

Remove all knobs and hardware from the cabinets with a screwdriver, and move the doors to a nearby area to be sealed separately.

Sand all wood surfaces of the cabinets, using a vibrating sander and fine sandpaper. Sand lightly, just enough to buff and degloss the surface. Clean up the dust with a vacuum cleaner.

Spread newspapers over the floors and walls around the area, taping them in place with painter's tape.

Apply polyurethane to the surface, starting at the top of each piece. Brush it on with a paintbrush in a light, thin coat, avoiding bubbles or drips. Let it dry about six hours.

Buff the dried polyurethane lightly, by hand, with fine sandpaper, dulling the shine. Wipe off the dust. Brush on a second coat of gloss in the same manner as the first. Let it dry.

Hand-sand the second coat. Brush on a third coat. Let it cure for two days before reassembling the cabinet.