Treatability of U.S. wood species with pigment-emulsified creosote.

Since the 1920s, creosote has been used extensively in the United States for treatment of construction timbers, poles, and posts. However, creosote has the tendency to exude or bleed from some treated commodities, producing a tar-like covered surface. In the United States, creosote-treated products exhibiting cleaner dried surfaces and a reduced tendency to bleed have been achieved through reduction of the xylene-insoluble carbonaceous fraction in creosote. In Australia, pigment-stabilized creosote emulsion formulations have been designed and developed to lock the oil phase within the treated timber and are referred to as pigment-emulsified creosote (PEC). The surfaces of PEC-treated commodities remain dry; the creosote does not leach into the ground or water in marine environments; and the oil remains mobile within the microstructure of the PEC-treated products. In this study, the treatment characteristics of southern pine, red oak, red maple, and Douglas-fir with PEC 30W are reported. Results showed that treatment of the four wood species with PEC 30W is generally comparable to treatment with reference creosote P1/P13, except that slightly greater variability in creosote loading occurs with PEC.