Popular Woodworking 2009-02 № 174, страница 54

But cherry blotches even without a stain. All clear finishes (even shellac, which is often promoted as an exception) blotch cherry and, of course, so does a washcoat. It seems there's no way to totally avoid the blotching.

This hasn't, however, stopped magazines over the years from keeping the possibility alive, hinting that there might be a secret method somewhere.

Not Always

One of the joys of woodworking is that we get to work with so many different woods, each of which has its own special characteristics

- some of which we like and some we don't. Cherry machines very nicely and has an especially pleasant aroma, but it blotches.

At least it usually blotches. Just as with pine and birch, which are also notorious for blotching, the blotching in cherry and whether it looks nice or not depends on the particular board. Some boards blotch in a particularly ugly way. Some blotch in a beautiful way

- often referred to as curly or mottled. And some don't blotch at all.

Unfortunately, no wood supplier grades cherry (or any other wood for that matter) by its blotching characteristics (though veneers are graded for curly and mottled). Wood suppliers grade wood for the number and size of its knots.

So you have to figure out for yoursel f how the cherry you are using will finish. This is much easier to do with surfaced cherry than with rough lumber.

With both situations, the easiest way to see how a finish will look on the wood is to wet the wood. Wetting gives almost the same appearance as a finish does, the difference being that the wetting evaporates and a finish turns to a solid making the coloring permanent.

You can use any liquid, but non-grain-raising liquids such as mineral spirits, alcohol and lacquer thinner are usually best, especially on surfaced wood.

Aging and Darkening

Besides blotching, another quality of cherry is the tendency of its heartwood to darken as it ages. The darkening is brought about by exposure to oxygen and light. Light accelerates the process, especially U V light, such as sunlight and fluorescent.

As cherry darkens, the blotching becomes muted - that is, the lighter non-blotchy areas darken to the color of the darker blotchy areas.

Washcoats. The left side of this cherry panel was washcoated, then Minwax cherry stain was applied to both sides (there is no stain on the middle stripe). Notice that the washcoat reduced the intensity of the blotching a little but didn't totally eliminate it. The washcoat also prevented the stain from coloring the wood as much.

Cherry variations. Cherry doesn't always blotch. It depends on each specific board. Both of these panels were finished with a clear finish - no stain. The left panel didn't blotch and the right blotched severely.

Test for blotching. The easy way to test for blotching is to wipe the surface of unfinished cherry with a liquid. Any liquid will work, but solvents such as alcohol, mineral spirits and lacquer thinner are best because they don't raise the grain like water does. It's much easier to see if a board will blotch when the test is done on surfaced cherry than on raw, unsurfaced cherry.

Natural darkening.

Cherry darkens as it ages due to exposure to oxygen and light. This 60-year-old chest has taken on the rich rust-red color typical of old cherry. Notice that the darkening has served to mute and disguise the darker blotching somewhat as the lighter colors have darkened to blend.

populara-oodworking.com ■ 71