SECRETS OF PAINT AND STAIN CHEMISTRY

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Fresh grass squeezings and vinegar makes a greenish black; steel nails left in vinegar for a week make a deep black (soak wood in it long enough and you get an ebony look-alike).

If you concentrate any of these juices by evaporating or boiling down, then mixing them with the natural latex in milkweed stems and pods, you'll have a natural rubber paint that is a woodman's tempera paint—color mixed with egg white, cooked flour paste, or calves-foot jelly (gelatin) that was an early fine art-painting medium. Milkweed paint is flexible and lasts on leather or canvas longer than brittle colors.

PIGMENTS AND SEALERS

You can make paint, putties, and sealers by mixing natural drying oils, shellac, varnish, or a colorless cooked-wheat-paste or gelatin/water binder with any filler and a pore-filling earth pig ment (such as super-finely ground sienna, umber or another natural color that is taken from the soil, refined and sometimes roasted—say, to derive burnt umber from the lighter native pigment). Iron oxide-containing red clay makes barn red; fine-milled carbon makes black pigment. Soot from oil lamps is a petroleum product and makes a semi-penetrating black pigment when mixed with oils or petro-solvents.

Wood that's to be painted can be sealed and smoothed with chalk in a natural oil or with chalk plus a wheat paste binder in a water base. Lightly sanding between successive dry coats gives you a sanding sealer that can produce a glasslike surface. Make white, dyed, or pigmented putties by decreasing fluid ingredients. The main difference between these natural products and cony mercial versions is nature's more limited palette, less convenience—and assurance of no toxic ingredients.

Plus, natural ingredients are often more costly than mass-produced chemical counterparts.

IS THIS PROGRESS?

A case in point is indigo, a blue dye originally obtained from a plant of the pea family. Cultivation of indigo was introduced to South Carolina in the 1740s (by 19-year-old Elizabeth Lucas) and it rivaled King Cotton in its day. But, in the 1950s, the essential oil of the indigo plant—called aniline—was isolated by treating indigo with potash (potassium hydroxide) leached out of wood ash. Then, in the 1950s, aniline was synthesized from benzene and quickly became the basis of a whole family of dyes. Former indigo plantations went into tobacco, and you know where that got us.

You can't buy natural indigo at reasonable cost anymore—if at all—but aniline dyes come in all colors, and are stable, long-lasting, and relatively inexpensive. Aniline dyes are also chemically the same as naturally produced by the indigo plant, except the source is artificial. And, fun as it sounds to smash a few plants and nut husks, doing it long enough to get really usable amounts of color is hard work. Most of us will be using modem dyes and stains. However, as with paints, ingredients in those little cans of wood stain are a mystery, though directions for use on the can labels are reliable. Read the label. If it says "don't shake," don't. You will introduce a billion tiny bubbles that can hold up till the finish dries. Shellac and varnish bubbles enough as it is.

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