Douglas fir is the strongest American wood available, making it ideal for flooring, wall paneling and high-use furniture such as kitchen cabinetry and heirloom-quality furniture. Its natural rose-gold tones are elegant and warm and the grain is beautifully patterned, but staining Douglas fir to bring out its natural beauty can be a challenge. The vertical grain can vary in porousness, making it hard to get even coloring. A little careful prep work and a lot of patience will go a long way toward helping you get the exact look you desire.
Sand your Douglas fir with 100-grit sandpaper to open its pores and prepare it to receive the stain. A coarser grit can cause small pits that will make the wood's tendency to look blotchy after staining even worse. Clean the wood with a soft nylon brush or a clean, lint-free cloth to remove all of the sanding dust.
Many different types of stain are on the market, but Douglas fir tends to take a gel stain best. The thickness of the gel slows its absorption a bit, allowing you to spread it more evenly before it sinks in, as compared with a thinner liquid stain. Dye-based stains work better with Douglas fir than pigment-based stains because they allow the natural patterns of the grain to show. Apply the gel with a staining sponge or clean, lint-free cloth. Work in long stripes following the grain rather than working across it. Be careful not to stop in the middle or to overlap the edges. Let the stain sit on the wood for three to five minutes, and then wipe it off with a clean cloth. Allow the stain to dry for six to eight hours before deciding whether to apply another coat or two to darken it.
Apply a clear sealer that is compatible with gel stain to help protect your Douglas fir from drying out or fading. Oil-based polyurethane resists scuffing and offers a soft, glossy finish. Water-based finishes also work but are not as durable. Use a natural-bristle or foam brush to apply the polyurethane. Use long, even motions to coat the wood with a very thin film. Work with the grain rather than across it, and watch carefully for air bubbles. Smooth them out as soon as they appear. Let the polyurethane dry for at least 24 hours.
Keep your stained Douglas fir looking fresh and new by keeping it clean. Avoid petroleum distillate–based polishes because they can build up over time. Use floor cleaners and furniture polishes formulated specifically for real wood. Apply polish to a dry cloth rather than pouring or spraying it onto the wood to help avoid buildup.
Make sure that your stain is completely dry before applying the finish. This is especially important if you are using both water-based and oil-based products on your wood.
Never apply stain or sealer in a closed room, as the fumes can cause dizziness.
Practice staining your Douglas fir on a piece of scrap wood if possible so that you can get a feel as to how it will accept the stain.