EVALUATION OF DIFFUSIBLE PRESERVATIVES USING AN ACCELERATED FIELD SIMULATOR

An accelerated field simulator was used to evaluate the effectiveness of eight diffusible preservative chemicals in preventing fungal attack of wood. Test samples were treated with the diffusible chemicals and then placed in the soil of the accelerated field simulator for 30 mont hs. Samples were then tested for residual strength in a modified stati c bending test. Samples were also evaluated for fungal attack by visua l and microscopic assessment. Both basidiomycete and ''soft-rot'' fung al attack was observed in most samples. In general, compounds containi ng creosote, sodium fluoride, or berate chemicals performed well in vi sual assessments, but samples treated with copper naphthenate retained the highest effective strength. Modulus of elasticity correlated well with the visual ratings of the samples in most cases; however, the vi sual rating system failed to predict the strength of some individual s amples.