How to Varnish a Cabinet

Attach a screwdriver drill bit to a cordless drill. Use the drill to remove the hardware and hinges holding cabinet doors in place. Place screws and hardware into a plastic, zippered bag. Mark the bag with a “1.” Peel off a piece of painter’s tape and mark with the same number. Write the same number on an additional piece of painter’s tape and place it inside the cabinet boxes. This helps keep everything organized and makes reattaching the doors easier. Continue with the additional doors, numbering them in sequential order.

Dip a sponge into a degreasing cleaning product. Using low strokes, rub the degreasing cleaning product all over the entire cabinet door. Degreasers remove any dirt and grime on wooden surfaces. Use an old toothbrush to work the product into grooves, holes and other intricate areas. Also, wipe down cabinet boxes. Repeat for all sides of the cabinet.

Apply carpenter’s wood putty to any unwanted cracks or holes on the cabinet surfaces. Squeeze a small amount of wood putty into the cracks or holes. Smooth out with a flat, putty knife. Allow the putty to dry completely before continuing.

Use medium-grit sandpaper to sand down the cabinet surfaces, removing the old varnish, stain or finish. Sand along the grain of the wood using long, even strokes. Use a tack rag to clean off any sanding dust. Finish by sanding with a fine-grit sandpaper to create a smooth, clean finish for the new varnish. Repeat on all doors and boxes.

Wipe down all sanded doors and cabinet boxes with a tack rag to remove any sanding debris. Attach a crevice cleaning tool to the vacuum to remove any remaining sanding debris.

Thin varnish in a paint tray by mixing together equal parts varnish and mineral spirits. This helps create an appropriate sealer for the new varnish finish. Pour the varnish-sealer through a paint strainer into a clean paint can or jar.

Dip a polyfoam or fine-bristled brush into the varnish-stain. Apply a thin, even coat to the surface of all cabinet doors and boxes. Paint in long, even strokes with the grain of the wood. Allow the varnish-sealer to dry overnight. Sand with a fine-grit sandpaper. Apply a second coat of sealer.

Mix together three parts varnish with one part mineral spirits to create a thin varnish. Thinning the varnish helps coats apply more evenly and reduces air bubbles. Pour it through a paint strainer.

Dip polyfoam or fine bristle brush into the varnish. Apply the varnish using the same thin, even strokes used to apply the sealer. Allow it to dry overnight and sand with fine-grit sandpaper. When using a thin varnish, several coats are necessary to fully cover the cabinet. Each project differs slightly; many wood projects require a minimum of six coats. Allow the varnish to cure for up to two weeks before reattaching the cabinet doors and hardware.