Oil finishes are among the easiest to apply. Most of them are simply a wipe-on, wipe-off process, being sure to remove all of the excess. Here is a step-by-step process you can use with any oil finish on the market today. 1. Prepare the wood. Remove any machine marks and sand new wood smooth to 180 to 220 grit. Oil finishes are thinner than their counterparts, so a finer grit is necessary. If you are finishing a tabletop it's a good idea to "sponge" the wood so water spills that work their way through the finish once the table is in use don't raise the grain of the wood. Humidity can also cause grain raising over a period of years and sponging will help reduce this also. Raised grain will cause an initially smooth surface to feel rough to the touch. 2. Clean the wood. Remove as much sanding dust as possible with a brush vacuum, compressed air, or tack cloth. For compressed air users, be sure you have an in-line filter/dryer in your system or you may end up spraying a fine mist of water onto your project. Also, I prefer a cloth dampened with mineral spirits to a retail tack cloth. These cloths contain wax which can lodge in the wood grain and cause problems with the finish. Mineral spirits will not cause this and also will not raise the grain of the wood. 3. Choose the finish. What kind of oil do you want? There are many different varieties of finishes marketed under the "oil" label. Straight oil, polymerized oil, wiping varnish, or oil/varnish blend. (A related article on different types of oil finishes is in the works.) If you've never used one of these before I suggest you begin with a wiping varnish (for a glossy appearance) or an oil/varnish blend (for a satin look). 4. Apply the first coat. Flood the wood with the finish. Wood will only hold a certain amount of oil at one time, so if you use enough to leave standing pools on the surface, that's all right. We'll be wiping off the excess in a little while. Application can be by cloth, brush, or spray gun, or you can dip the wood into the finish. Leave it to dry for about five minutes. The temptation to move faster will be there. Resist it. If any dry spots appear, apply more finish. Before it becomes tacky, wipe off all the excess finish. Polymerized oil and wiping varnish will become tacky faster than straight oil or oil/varnish blends, especially in high temperatures. These products may require excess removal before five minutes have passed. 5. Remove "bleeding" before it cures. Many oils can bleed back out of the pores in the wood. Small puddles may form after you remove the excess oil. Wipe these dry and keep wiping them dry until they stop forming. 6. Apply additional coats. Let the first coat dry overnight. Smooth any remaining roughness with 400-grit sandpaper. Clean the wood as in step 2 again and apply the next coat. You can even combine these two steps by sanding the wood with wet/dry sandpaper while the wood is wet with the second coat of finish. Wipe the wood dry as before. You can then add as many coats as you like, allowing a full day drying time between coats. However, unless you are using a wiping varnish or polymerized oil there is no reason to apply more than four coats, as these finishes do not build like more solid finish. Follow these steps and you will end up with a warm, soft glow to your project that will last for many years to come. |
