Not every wood project benefits from a coat varnish or a polyurethane finish. Danish oil can intensify the colors in woods with rich grain patterns, making the variations in the wood stand out. Derived from linseed or tung oil -- depending on the manufacturer -- Danish oil penetrates the wood deeply, but leaves a slightly hardened surface and satin sheen when cured. Danish oil isn't hard to apply, it just takes a bit of time to cure. The oil works best on items that don't see a lot of hard use such as bookcases, craft and jewelry boxes, picture frames, and hope or blanket chests. Wear the appropriate safety gear, including goggles, a dust mask and vinyl gloves when working.
Smooth the Wood
Prepare the wood surface as you normally would for staining and varnishing. Smooth the wood by sanding it with 180- or 220-grit sandpaper, working in the direction of the grain. After sanding, remove dust by wiping the entire project piece with a tack cloth -- one bought from the store or one you make yourself. Mix together 1 part shellac to 1 part denatured alcohol in a canning jar with a lid that you can tighten for storage. Dip cheesecloth into the solution; wring it out and let it dry until tacky for a homemade tack rag.
One-Day Coating Method
Fold a small piece of lint-free cloth -- microfiber cloths work well for this -- and pour a bit of the Danish oil right from the can onto the wood project. Rub the Danish oil into the entire piece with the cloth, letting it soak into the wood for 20 minutes before applying a second coat. Wait another 20 minutes after applying the second coat before wiping it off with a clean rag. Wait an hour, and then wipe any remaining oil from the wood, applying a bit of extra oil to any dry spots. After another hour, or when the wood is dry to the touch, wipe it down one more time with a clean cloth. Let the wood cure for 48 hours before using. Remove burrs after the entire item has cured, using 400-grit wet-dry sandpaper. Coat with a liquid or paste wax as a final sealant.
Pour a dab of Danish oil onto the wood item directly, or blot it onto a lint-free cloth. Liberally apply the oil to the wood, rubbing it into the surface with the cloth. Remove excess oil after 20 minutes by wiping with a clean rag. Let the wood dry for 24 hours and reapply a second coat in the same way as you did the first, removing excess oil after 20 minutes with a clean rag and letting it dry for a full day. On day three, add another coat and remove after 20 minutes, allowing 24 hours for it to dry. Once the wood takes on a wet look and stops absorbing oil, usually by the third coat, allow it to cure until it is not wet to the touch. If you desire a smoother finish, after each coat has cured, sand with 400-grit wet-dry sandpaper. As a final finish, apply a hand-rubbed paste wax for protection.
You can also mix a bit of varnish with Danish oil, if you prefer a more hardened and stronger surface. Mix together 1/3 Danish oil, 1/3 paint thinner and 1/3 varnish in a jar that you can seal, or choose a Danish oil that already has varnish in it. Another option is to apply a varnish coat after the Danish oil has thoroughly cured for a more durable finish.
When Not to Use Danish Oil
Danish oil doesn't work on aromatic woods, because they contain antioxidants that prevent the oil from curing correctly. Don't use it on cedar or wood from the pea family, or on dalbergia woods such as rosewood, tulipwood or cocobolo. Don't use Danish oil on countertops, or kitchen, coffee and end tables unless you cover it with a varnish or polyurethane -- Danish oil alone is not durable enough to withstand the beating these items undergo.