How to Finish a Knotty Alder Door

The rustic charm and warm color of knotty alder makes this type of wood an option for doors, furniture and cabinetry. By staining the knotty alder yourself, you are in control of the specific shade of the wood. Adding a finishing coat to your stained alder door seals and protects the wood from moisture, dirt and the elements.

Wood finish with a UV protective additive
220-grit sandpaper
Mineral spirits
Paintbrush
Rubber gloves
Bucket

Instructions

- 1
  Purchase polyurethane, lacquer, varnish, or shellac for finishing interior alder doors. Use a spar finish on external doors; this is a a UV-protective additive that prevents fading. Read the product's directions thoroughly before beginning.
- 2
  Move your door outside or to a well ventilated area. Stain the knotty alder door to your desired shade. Allow the stain to dry thoroughly according to the product directions. The average drying time is two to six hours, but stain products vary. Reapply the stain if you want a darker color.
- 3
  Sand the entire wood surface with steel wool or 220-grit sandpaper. This gives the varnish a surface that it can grab onto.
- 4
  Wear rubber gloves and dilute your finish with mineral spirits. This usually provides an even finish. Dilute the solution to 25-percent mineral spirits and 75-percent finish.
- 5
  Apply a thin, even layer of your diluted finish to the entire surface with a paintbrush or an old T-shirt. Allow it to dry according to the product instructions. Depending on your chosen product, your drying time between finish coats might range from 4 to 24 hours.
- 6
  Sand the surface lightly with steel wool or 220-grit sandpaper, and reapply another coat. Repeat this until you have five coats of finish the door.
- 7
  Flip the door over and repeat the procedure.

How to Install a Prehung Bedroom Door

How to Install a Swinging Door Hinge

Doors