Heavy duty treatment braced for revival

treated wood is commonly used for utility poles, marine piling, structural timbers, guardrail posts, retaining walls, fence posts, and other heavy duty uses. Its newest use is unlikely to revolutionize railroad purchases, but ACZA crossties offer an economical alternative to traditional creosote ties. They are particularly suited for shortlines and industrial spurs.

Sometimes ACZA wood products are sold directly to specifiers, engineering firms, or farmers. In other cases, they are sold through lumber yards to contractors, often on a "Treating Service Only" basis. Bob Palacioz, Thunderbolt Wood Treating, Riverbank, Ca., explains, "We treat wood from dealers and wholesalers on TSO orders. They send us their wood, we treat it, and they return it to their yards or deliver it directly to the jobsite."

f, cneNo oLD wooD IRESERVATTvE, capable of protecting .fa,species that other chemicals cannot, may be poised for a revival. It made news recently with an expanded listing in the treated wood standards, and is being considered more frequently for heavy-duty applications.

Ammoniacal copper zinc arsenate (ACZA or often known by its brand name, Chemonite) was formulated in the 1980s by J. H. Baxter & Co., San Mateo, Ca., which continues to treat with it. The Baxter formulation replaced a related preservative developed 60 years earlier at U.C. Berkeley. Both were created specifically to penetrate refractory (i.e., hard-to-treat) species such as Douglas fir. This remains its primary use today, but not its only feature.

ACZA has long been listed for a variety of applications by the American Wood Protection Association, which establishes standards for the wood preservation industry. In January, a new application was added: Douglas fir railroad ties.

"Douglas fir is a very valuable and desirable wood," says Darrell Smith of Conrad Forest Products, a North Bend, Or.-based producer of ACZA-treated material. "It is strong, dimensionally stable, and has good nail-holding power. Although it is hard to treat with other preservatives, it is preserved well with ACZA."

The ACZA treating process, which combines incising, conditioning, and heat, can impart termite and decay resistance to refractory woods.

Taking advantage of the properties of Doug fir, ACZA-

While Doug fir is the usual wood treated using ACZA, the preservative can also provide effective protection for other species. Says Aaron Hufnagle, Page & Hill, Big Falls, Mn.: "We're unique among ACZA treaters. We specialize in red pine posts, poles, and piling, as well as sawn timbers. The benefits of Chemonite ACZA preservative have kept us treating with it for more than 20 years."

In addition to protecting against fungal decay and termites, including the Formosan termite, tests have offered evidence that ACZA also imparts resistance to fire. ACZAtreated wood meets model buildins codes.

North ldaho Wood Preserving (Rathdrum, td.)

Oeser Co. (Bellingham, Wa.)

Pacific States Treating (Weed, Ca.)

Pacific Wood Preserving Cos. (Eloy, Ar.; Bakersfield, Ca.; Nevada Wood Preseruing, Silver Springs, Nv.; Sheridan, Or; New Willard, Tx.)

Permapost Products (Hillsboro, 0r,)

PSR Co. (Kirkland, Wa.)

Royal Pacific Industries (McMinnville, Or.)

Ruby Valley Pressure Treating (Alder, Mt.)

Simmons Wood Products (Maricopa, Az.)

Stella-Jones Corp. (Arlington, Wa.; Fulton, Stanton, Ky.; Dubois, Pa.; Goshen, Va.; Spencer, W.V.; Bangor, Wi., plus 15 treating plants in Canada)

Superior Wood Treating/Manke Lumber Co. (Sumner, Wa.)

Thunderbolt Wood Treating (Riverbank, Ca.)

TrueGuard, LLC/Coos Head Forest Products (North Bend,0r.)

Utah Wood Preserving (Woods Cross, Ut.)

Western Wood Preserving Co. (Sumner, Wa.)

Western Wood Products (Raton, N.M.)

Western Wood Treating (Weed, Ca.)