Getting the color right
If you’re building a piece to match existing furniture, you have a color challenge. If you’re replicating an architectural detail, you’ll, very likely have a color challenge. So what do you do? Obviously, you can’t paint everything. Do you run down the street to the local finisher’s shop and have them take care of it for you? Eh? Maybe, if you live in New York, Paris or Budapest. But it ain’t happenin’ where I live. Plus, I just don’t have that many customers who are willing to see signicant increase in cost to get a really incredible finish. So..we do the best we can.
Color is a big stumbling block. If you can get it right (or even close), you’re halfway home. If I’m working with bare wood, I’ve gotten in the habit of using artist oil colors for staining. They’re simply mixed with BLO (boiled linseed oil) or raw linseed oil. If you go the raw route, you may want to use a little Japan dryer (usually not more than 5% by volume). With just several colors, you can match, or create, an amazing number of stains. Your basic color kit should contain raw umber, burnt umber, raw sienna, burnt sienna and ivory black (some folks prefer Payne’s grey).
You’ll want to be aware that colored fill and/or overglazing might come into play when trying to analyze a color match. After you’ve determined which color is best suited for the match, you simply mix a small amount with the medium (i.e. BLO). Treat it as you would any oil stain. Apply it liberally and wipe the excess away while it is still moist. Allow adequate drying time (8-24 hours) before re-coat. You may find that you are unable to produce as dark a color as you require. In this case, try the addition of a little black (blue may sometimes be added to “cool” a color). Also, the level of reflectivity will change the perception of color darkness. Experimenting with top coats is a valuable expenditure of time when trying for a correct color.
Another method of darkening a finish is to color the top coat. Colored varnishes have been used for centuries. Various colored resins will affect spirit varnishes (shellac). And, dyes which are soluble in oil, spirits or water can be very useful. There is only one caveat about using colored top coats; lap lines can be a significant problem. So, practice your brushing or spraying technique.
Milk paint is another vital tool in the shop. When mixed as a diluted wash, it can provide beautiful staining results. However, it will raise grain. Mixol is a product that can be used to color just about any medium. It is fairly expensive, but very effective. And, it offers the craftsman a huge range of color choices. Chemical dyes (i.e. lye, potassium permangenate, nitric acid, etc.) can produce incredibly beautiful, transparent and permanent colors on wood. However, proper selection requires an understanding of the chemical reactions involved and how effects vary from one wood species to another. Experimentation is a must. Also, chemical staining requires additional safety and handling considerations.
The best text that I’ve found on many specialty methods of coloring wood is “Classic Finishing Techniques” by Sam Allen. “Flexner on Finishing” is alway a great resource on finishing. And, “The Natural Paint Book” is a very interesting overview of many coloring methods.
Finishing is hard work. But many times it is the attention to and expertise in finishing that separates the master woodworker from the gifted amateur.