Characteristics of oak: final installment

NE MORE point about oak pertains to all of the members of the oak family. Wood technologists call oak a refractory species, which means it's difficult to dry. Regardless of how good an oak log may have been in the woods, the lumber will be only as good as the drying.

Generally oak lumber should be airdried to below 307o moisture content before going into a dry kiln. The green lumber should be stored in a cool, shaded shed or protected under roofcovers and wrapped in burlap. Lumber dried in kilns that use kiln cars on ffacks sometimes comes out befter than lumber dried in kilns loaded by forklift because by design the track kilns assure a constant, even flow of air over the lumber. Oak must be dried according to a proper

Sizer

kiln schedule. Lumber dried too quickly will come out full of tension and sometimes loaded with honeycomb or cell collapse.

Perhaps the most important step in the treatment of oak comes after the lumber

Story at a Glance

Oak is only as good as the drying .observation of colo6 texture, visible defects is the best way to evaluate oak.

Timbers

From cutting a wedge to pre-fab'd crane pads or mine shafts. Angle cut, cross cut, drilling, dapping-Ve'll do them all to customer specification.

is dried, but while it is still in the kiln. This is calledsffess relieving. It is a conditioning treatment that consists of subjecting the dried lumber to a high temperature and high relative humidity for a day or two. When demand for oak is great, as it is now lumber manufacturers are tempted to push their production through the kiln process too quickly. But the best producers of oak lumber always stress relieve their stock, thereby assuring the consumer a stable product that will not spring when cut. Don't hesitate to ask your lumber supplier whether his oak has been stress relieved.

Lumber people and craftspeople agree that all of the written information on oak lumber cannot substitute for the experience of buying lumber from different geographical areas and the experience of working with it. A thorough examination of the product with special attention to color. texture. and visible defects is the best way to evaluate any lumber. But much can be leamed by asking questions of your hardwood supplier. Any knowledgeable lumber person enjoys the opportunity to talk about the quality, workability, drying and milling of his oak lumber.

This k the fual article in a fve part mini series on the characterisics ofoakwritten a1\ Gage McKinney, a contributing editor of thi,s magazine.--ed.

Redwood Millwork

(Continued from page I6)

Tirrning & Milling is a good example of the company's professional pride. It includes well over a hundred different products and includes instructions for handling, storing and installing balusters, newel posts and columns. It illustrates the care that is taken in choosing quality materials and design accuracy.

Realizing that architects were the major market for his products, Miller mailed catalogs to an extensive list of architectural firms across the country. Response from such mailings can typically be from 2 to sEo, but Miller claims he had nearly a 20Vo response from his mailing after only six weeks.

Miller's catalog which normally sells for $3 is available free to Merchant Magazine subscribers on request by writing Robert Miller, Architectural Wood Turning Service, PO. Box 225, Woodacre. Ca.94973.