Kiln Drying'Western Pine

Western Yellow Pine (Pinus Ponderosa) distributed, inland, from British Columbia to Northern Mexico, is one of our most valuable commercial soft woods. Its proper kiln drying is of great importance to operators because tlrere is large degrade from blue stain when it is shippcd grecn or rir-dried in the yard, especially during fall, winter and spring months. For pine ,m,ills, dry kilns are indispensable. A good kiln is the means of quick turnover of stock and capital, and underweights for eastern shipment-as'all pine mills are inland mills. This not only applies to kiln drying the upper grades but the lower grades as well.

The proper kiln drying of Western Yellow Pine has offired problems which have ar'oused much discussion and in. terest in the pine belts of Washington, Oregon, Idaho and Ca-li.fornia. Kiln stain elimination and drying out the large prcr:cent of water or sap in this stock, in the mini,mrtrm of time and of stearn consumption, has called forth the best efforts of mills and dry kiln cornpanies.

The problems invblved are different from those encountered in drying other western soft woods. In the first place, w€stern pines contain much ,rn,ore water or sap, averagin'g fro4 85 per cent to I75 per cent moisture-content based upon bone dry weight. In th,e second place kiln 'drying is complicated by the occurrence of brown stain under the surface of sap boards, which produces considerable degrade, unless properly designed kilns are used, and intelligent operation is had. This stain seems to be increased when stock is cut from old logs and can only be held to a minimum. by careful kiln operation and'moderation of temperature schedules.

Stain prevention and quality drying, requires low temperatures not exceeding 190 degrees, and averagin$ from 160 to 180 degrees, depending upon the stock being dried. Getting most satisfactory results requires the removal of the large amount of moisture or sap, which this stocl{ conrtains, as fast as it com'es to the surface. Sweating in the kiln intensifies stain.

The Bowman-Hicks Lumber Co. at La Grande, Oregon, who have recently installed a battery of 4 Moore single charge dry kilns (shown in pictures on opposite page) are getting exceptionral quality of drying in the minimum time, and 'their operation will be of general interest to pine operators.

They have a brttcry of ten kilns all of modern fi1e pr99f constriretion. Their litely installed 4 Moore kilns havt l?inch outside tile walls with tile and concrete roof. The]" are of single-chrrge compartmenrt type open one end only with operating pit at back end. Tracks are level. La Grande is also the hom'e of Dan R. Turner who worked oqt the details of the sorting ind dry kiln stacking systems of which photographs are stown. Cars of lumber are handled from stackers through dry kilns and to unstlckers by means of electric transfer with cable. One rlnn''and sometimes a helper does this handling. .

The simplicity of Moore Pine Kilns is one of their biggest assets. The illirstrations above and at left and, description points out their main features.

Sufficient pipe is used to reach quickly drying temrp€-rature at the .stirt, and to give large drying Power. This pipe is installed ini 3 full lines of pipe beneath the lumber io give equal heat at the twrr ends of kiln. It is distributad throughout the space beneath the lurnbtr to'heat volume of air, eoils have good drainage and are economical in steam consumption, als-o take carJof expansion in the simplest manner. It is a high powered heating system.

We Offer

I car-Ye" FAS PLAIN WHTTE OAK

3 car*3/e" FAS PLAIN WHITE OAK

3 cars44' FAS PLAIN RED OAK

4L w lt. G. BoHtssEll WZ knrfrtrdng oF

H.A,RDWOOD LUMBERffi' If

IHlandw@od

Pnobebty tho greatgt vrricty of herdwoodr iD th. wlolc thtGd $rlG.

TIb & BRANNAN ST3. ; - . SAN FRANCI!'CO

Havc you rcccivcd a @py of ou booHc't, sOrigin and Hirtory of Hardwoodl" hficly publirhcd. Scnd for r colry. You will bG iutc!.dcd.