Old oak doors are dense and sturdy, providing a high-quality door that will compliment your home. There was a time when applying a dark stain to doors was in vogue and, if your oak door was finished in this manner, it may be too dark for your tastes today. If you prefer the lighter look of natural oak, you can strip off the old finish and bleach the doors to remove the stain. It's a time-consuming process but when you're done, your oak doors will glow with their new lighter look.
Removing the Finish
Before you can bleach the old stain away, you must remove the old finish coat. This may be polyurethane, varnish or shellac. A chemical stripper will soften the old finish, allowing you to scrape it away with a paint scraper. The doors should be removed from the hinges and placed on a flat surface for stripping.
Oxalic acid will bleach the old stain without damaging the oak grain. Available from paint centres, you must mix the oxalic acid with hot water, and brush it on the oak door. As the solution dries, it will lighten the old stain. You may apply the oxalic acid solution more than once if you want lighter wood.
Applying the New Finish
The bleaching process may raise the oak grain, making the doors feel slightly rough. You can smooth down the doors with sandpaper before applying the new finish.
Once lightened, you may re-stain the oak or apply a clear coat. Since the oxalic acid will lighten the naturally dark streak of grain, an oak stain may offer the best results.
Tools and Supplies
You'll need a natural-bristle brush to apply the chemical stripper and a couple of paint scrapers in different sizes for removing the loosened finish. Use a plastic bowl and spoon to mix the oxalic acid, and wear chemical-proof gloves and splatter-proof goggles when you brush it on the doors.
120-grit sandpaper will smooth the oak grain and a stain applicator pad is helpful for applying new wood stain.