Western juniper product trials in 1992 and 1993 revealed a potential problem with excessive end-splitting during drying and remanufacture. Splitting reduces raw material recovery and may cause reductions in quality and value of finished products. It was theorized by academicians and manufacturers that the problem might in part be caused by "raw material handling", e.g. excessive log storage time and improper log storage methods.
Oregon lottery funding was obtained by the Western Juniper Commercialization Steering Committee to study effects of differing log storage methods (end-coated vs. non end-coated) and storage duration on product recovery and value. The sample set consisted of 25 logs: Eight were left as a control, 8 were end-coated on both ends, as well as all knots over 3 inches, and 9 were simply coated on both ends. All were harvested in early October, 1995, from the same site and classified as "saw logs" by a local mill with experience sawing juniper.
A representative sample of the "green" logs were sawn into lumber, dried, and remanufactured into finger-joint blanks. The remaining logs were sawn, dried, and remanufactured into finger-joint blocks after 250 days of storage.
Recovery figures (see formula below) for lumber and finger-joint blanks were calculated for both storage periods. See the Log Storage Project Recovery Table below for results.
|Log Storage Project Recovery Table|
Timing of Sample
|Green (less than 30 days)||1.66||53%|
|After 250 Days||1.43||45%|
Lumber recovery was approximately 20 percent greater for green logs than for logs stored for250 days. Finished product recovery in the form of finger-joint blanks was 53% for lumber sawn from green logs and 44.7% for lumber sawn from logs stored for 250 days. This slight decrease in finished product recovery is likely insignificant.
Data were unable to be gathered comparing specific effects of log storage on end-coated versus uncoated material. It was impossible to distinguish end-coated versus uncoated logs after 250 days due to weathering. End-coating probably contributed to a better than expected lumber recovery, however, to what extent could not be determined.
For more information, contact Scott Leavengood, OSU Extension Service 541-883-7131.
The full report is available on-line at http://juniper.orst.edu/storage.htm