Equilibrium Moisture Content of Wood in Outdoor Locations in the United States and Worldwide

Equilibrium Moisture Content of Wood in Outdoor Locations in the United States and Worldwide
Author: William Turner Simpson
Publisher:
Total Pages: 18
Release: 1998
Genre: Lumber
ISBN:
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With relative humidity and temperature data from the National Oceanic and Atmospheric Administration, the average equilibrium moisture content for each month of the year was calculated for 262 locations in the United States and 122 locations outside the United States. As an aid for storage of kiln-dried lumber, a graph is presented for determining the reduction in equilibrium moisture content that results from heating air in an enclosed storage space above the temperature of the outside air.

Evaluating Shrinkage of Wood Propellers in a High-temperature Environment

Evaluating Shrinkage of Wood Propellers in a High-temperature Environment
Author: Richard D. Bergman
Publisher:
Total Pages: 12
Release: 2008
Genre: Propellers, Aerial
ISBN:
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Minimizing wood shrinkage is a priority for many wood products in use, particularly engineered products manufactured to close tolerances, such as wood propellers for unmanned surveillance aircraft used in military operations. Those currently in service in the Middle East are experiencing performance problems as a consequence of wood shrinking during long-term storage at low equilibrium moisture content conditions prior to installation. To evaluate the extent of shrinkage, seven sugar maple (Acer saccharum) veneer propellers were dried from 11% to 3% moisture content in a controlled environment of 150°F (65°C) for 3 days. Two of these wood propellers were encased in polyethylene bags. Results showed 5 to 20 times more shrinkage for the thickness of the propeller hub and the hub face perpendicular to the propeller blades (across the grain), respectively, compared with the hub face parallel to the blades (along the grain). Two hubs, coated with aluminum oxide paint, showed dimensional changes similar to those observed for uncoated hubs. For the two wood propellers encased in polyethylene bags, moisture loss was slowed during the course of the experiment by roughly 46%. Wrapping the wood propellers prior to shipping would slow moisture desorption, thereby minimizing shrinkage during short-term storage. Processing the propellers at a lower equilibrium moisture content would minimize shrinkage during long-term storage.

Guide for Use of Wood Preservatives in Historic Structures

Guide for Use of Wood Preservatives in Historic Structures
Author: Stan LeBow
Publisher: Government Printing Office
Total Pages: 68
Release: 2012-12-13
Genre: Architecture
ISBN: 9780160915178
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NOTE: NO FURTHER DISCOUNT FOR THIS PRINT PRODUCT-- OVERSTOCK SALE -- Significantly reduced list price Wood preservatives are generally grouped into two categories: preservatives used for in-place field (remedial)treatment and preservatives used for pressure treatments.A limitation of in-place treatments is that they cannot beforced deeply into the wood under pressure. However, theycan be applied into the center of large wooden membersvia treatment holes. These preservatives may be availableas liquids, rods, or pastes. Pressure-treated wood has muchdeeper and more uniform preservative penetration thanwood treated with other methods. The type of pressuretreated wood is often dependent on the requirements of thespecific application. To guide selection of pressure-treatedwood, the American Wood Protection Association developedUse Category System standards. Other preservative characteristics, such as color, odor, and surface oiliness may alsobe relevant. Guidelines for selection and application of fieldtreatments and for selection and specification of pressure-treated wood are provided in this document. Related Products: Nondestructive Evaluation of Wood is available here: https: //bookstore.gpo.gov/products/sku/001-001-00704-8 New Exterior Additions to Historic Buildings: Preservation Concerns is available here: https: //bookstore.gpo.gov/products/sku/024-005-01280-0 Guide for In-Place Treatment of Wood in Historic Covered and Modern Bridges is available here: https: //bookstore.gpo.gov/products/sku/001-001-00695-5 Preserving Historic Wood Porches is available here: https: //bookstore.gpo.gov/products/sku/024-005-01240-1 Preservation Briefs: Recognizing and Resolving Common Preservation Problems, 1-14 is available here: https: //bookstore.gpo.gov/products/sku/024-005-01026-2 Preservation Briefs: 15-23 (2007) is avaiable here: https: //bookstore.gpo.gov/products/sku/024-005-01256-7 Preservation Briefs 24-34: Recognizing and Resolving Common Preservation and Repair Problems Prior to Working on Historic Buildings is available here: https: //bookstore.gpo.gov/products/sku/024-005-01147-1 Preservation Briefs 35-42: Recognizing and Resolving Common Preservation and Repair Problems Prior to Working on Historic Buildings is available here: https: //bookstore.gpo.gov/products/sku/024-005-01219-2 Renovation & Historic Preservation resources collection can be found here: https: //bookstore.gpo.gov/catalog/science-technology/construction-archit"

House Log Drying Rates in Southeast Alaska for Covered and Uncovered Softwood Logs

House Log Drying Rates in Southeast Alaska for Covered and Uncovered Softwood Logs
Author: David L. Nicholls
Publisher:
Total Pages: 24
Release: 2009
Genre: Log cabins
ISBN:
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Log moisture content has an important impact on many aspects of log home construction, including log processing, transportation costs, and dimensional stability in use. Air-drying times for house logs from freshly harvested trees can depend on numerous factors including initial moisture content, log diameter, bark condition, and environmental conditions during drying. In this study, we evaluated air-drying properties of young-growth Sitka spruce (Picea sitchensis (Bong.) Carr) and of western hemlock (Tsuga heterophylla (Raf.) Sarg.) from logs harvested in southeast Alaska. For each species, we considered inside storage in a warehouse vs. outside storage, as well as debarked logs vs. logs with bark remaining, resulting in four experimental treatments. We considered moisture losses after 8 and 12 months of air drying. There was considerable moisture loss for Sitka spruce logs, and much of the drying occurred during the first 8 months. Fastest drying rates for both species were for peeled logs with inside storage. Western hemlock logs showed higher moisture content and greater moisture content variation (vs. Sitka spruce), and in most cases would require additional drying beyond the 12-month study period to produce satisfactory house logs. Results of this study are significant because they can help entrepreneurs determine appropriate levels of capital investment (e.g., land, covered storage, debarking equipment), as well as whether to dry and process logs in southeast Alaska vs. some other location. This study found that a leading option for local producers would be to peel Sitka spruce logs, then air dry indoors for between 8 and 12 months. Another effective strategy would be to peel western hemlock logs, then air dry indoors for 12 months.