The gain by kiln-drying, in time and money, is, therefore, more or less offset by impairment of the quality of the wood, so if you can find stock that you know has been seasoning for years by the natural process, buy it by all means for your nice work, even if you have to pay more, regardless of what the dealers in kiln-dried stock or the makers of articles for sale may tell you about the advantages of kiln-dried wood.
On the other hand, if a dealer brags of his new patent "chain-lightning" dryer that will make green wood "dry as a bone" in two or three days, go elsewhere to buy your stock, for wood dried in a few days is not the kind to use for good work. You will probably have to use kiln-dried stock for most, or, perhaps, all of your work, but get it from a slow-drying kiln and keep it for further seasoning as long as you can.
Even if wood has been well seasoned, it is best, before putting it into nice work, to cut it up and dress it approximately to shape and leave it in a dry place for some time for a final seasoning, particularly in the case of thick stock. Do this with kiln-dried stock fresh from the dry-house. Let it have a little time to get into harmony with the atmosphere. Whenever wood has been exposed to damp air, as in a wet shed or cellar, let it stand in the warm shop a while before using it for nice work.
The stock is arranged for seasoning so as to allow the air to circulate around and between the pieces. A common way is simply to arrange them in piles, each piece being separated from those above and below by strips or sticks laid across (Fig. 28). These sticks should be placed directly over one another, and so that the lumber will lie straight, else the weight of the pile, which should tend to make the pieces dry straight, will have the opposite effect and make them permanently crooked. There are other ways of arranging wood for drying, but this method is common and illustrates the most important principles. Stock is sometimes stacked upright, and small pieces are occasionally hung up for such nice work as billiard cues and bows.
Fig. 28.
Seasoned wood is lighter in weight than green, dryer to the touch, usually has a different odour, cuts differently when you whittle it (and the piece you whittle off breaks differently), and it shows a difference when you saw it. It is impossible to define these differences and you will have to learn them by actual work. It is not always easy even for an experienced person to tell with certainty about some pieces until he has "worked" them, so much do the characteristics of different pieces vary. One test is to rap the boards sharply with a hammer. A green board and a dry one of the same kind will "rap" differently,—that is, will have a different vibration and give out a different sound. Of course this cannot be described, but you can judge quite well in this way. It is one of the many things you can learn only by experience. You can ascertain much about the character and condition of lumber by sawing or planing or whittling a piece. This is a good test for dryness, toughness, and elasticity (which you can tell about by breaking the shavings).
Weather-dried timber is usually somewhat darkened from exposure, but kiln-drying lightens the colour of some woods.
Stock with a bright lustrous appearance and of dark hue is generally superior to that of a lighter colour and duller appearance, but such characteristics depend much upon the kind of wood. Green wood is tougher than seasoned wood, but the latter is more elastic. To subject seasoned wood to moisture and heat brings it back, to a certain extent, to its original condition, and renders it for the time being tougher, hence the process of bending wood by the application of steam or hot water (see Bending in [Part V].).
Reject "wany" lumber, or that of which the edges or corners have not been squared (Fig. 18), and also boards and planks which have not been sawed to a uniform thickness. It is not uncommon for a board to be considerably thinner than it should be in some part of its length, due to irregularity in sawing.