Water-Borne Copper Naphthenate: An Emerging Wood Preservative
P Nzokou, D P Kamdem, M H Freeman
Waterborne copper naphthenate (WB Cu-N) was used to treat southern yellow pine (Pinus spp) and red maple (Acer rubrum) stakes. The treated stakes were exposed in test sites located in Florida, Michigan and Mississippi for 3 to 6 years. Copper Chromium Arsenate (CCA),
Ammoniacal Copper Quat (ACQ) and Oil-borne Copper Naphthenate (OB Cu-N) were also used to treat some stakes for comparison. Results obtained showed that decay fungi and termites destroyed untreated samples within 2-3 years on all sites. After 3 years exposure in Florida, red maple stakes treated at retention of 0.04pcf (0.561kg/m3) were destroyed by decay fungi and termites. All red maple treated above 0.07pcf (1.092 kg/m3) and yellow pine treated at retention ranging from 0.04pcf (0.708 kg/m3) of copper to 0.68pcf (10.9 kg/m3) of copper from WB Cu-N performed well. After 6 years exposure in Mississippi and Michigan, 0.07±0.007pcf (0.708 kg/m3) and 0.12±0.01pcf (1.95 kg/m3) of Cu metal from WB Cu-N respectively for yellow pine and red maple, offered a good protection comparable to CCA and ACQ treatments. This study clearly suggests that WB Cu-N can be used as a wood preservative for both above ground and ground contact applications.
Keywords: Waterborne Copper Naphthenate - southern yellow pine – red maple – retention - field test – decay rating