A field trial of water repellents as anti-sapstain treatment additives
J A Drysdale, D V Plackett
The assessment of water repellents as anti-sapstain treatment additives has been included in a recent FRI research programme investigating improved surface protection of New Zealand Pinus radiata. Laboratory work has shown variation in water repellent effectiveness with chemical type and subsequently a field trial was established to examine the performance of selected water repellent/anti-sapstain treatments. Three water repellents were tested in combination with either sodium pentachlorophenoxide plus borax, Busan 1009 (methylene bisthiocyanate plus 2-(thiocyanomethylthio) benzothiazole), or Mitrol PQ375 (copper-8-quinolinolate). Although inspection of treated wood packages after 3 months' outside storage showed little variation in performance, inspections after 6 months showed that wood treated with formulations incorporating a paraffin wax emulsion was drier and usually showed less fungal degradation than wood treated with unamended anti-sapstain solutions.