A summary of work carried out to compare natural and artificial weathering for preconditioning test specimens in testing anti-stain chemicals for wood in service
D J Dickinson, A F Bravery
Since 1972 work has been in progress within CEN to establish a European standard for the testing of wood preservatives designed to prevent blue-staining of wood in service. The method is based on the Butin test and involves pre-weathering of the samples prior to biological testing. The weathering regime employed is 6 months outside exposure from March to October. This imposes severe limitations on the number of tests that can be carried out each year and has prompted considerable interest in an artificial weathering procedure which can be used instead of natural weathering. Recently four European laboratories (EMPA, BAM, IC, PRL) have been involved in assessing artificial systems (Xenotest, Marr, Gardener wheel, weathering tunnel) and this report has been prepared at the request of CEN in order to assess the accumulated data and make recommendations back to the CEN. This document presents only a brief account of the work and fuller details can be obtained directly from the laboratories concerned.