Preventive effectiveness of petrol derivatives against blue-stain fungi
A M Navarrete, M T De Troya, E Sanchez, A Guijarro
A possible application of fractions obtained on petrol pyrolysis is their use as a wood preservative against wood-decay and sap-stain fungi. From two of these fractions were prepared three different products (ST, STL and SST). The aim of this work has been the possibility of utilizing these products in the treatment of wood used for external joinery, determining their effectiveness against blue-stain fungi and their compatibility with existing surface coatings. Test blocks of Pinus sylvestris and Pinus pinaster were used, treated with a brushed application of the above products, and then two different kinds of coating. The wood blocks were then exposed to 3 months of weathering. After this time they were placed in contact with pure cultures of Pullularia pullulans and Sclerophoma pityophila in sterile conditions, for 6 weeks. After the period of weathering the degree of varnish adherance was evaluated. The effectiveness of the preservatives was assesed by determining the penetration depth of the hypha into the wood face. The results obtained revealed that only ST and SST were effective against blue-stain fungi for wood in service, whereas the degree of compatibility with the coatings varied.
Keywords: BLUE STAIN; PETROL DERIVATIVES; PINUS PINASTER; PINUS SYLVESTRIS; EN 152; PULLULARIA PULLULANS; SCLEROPHOMA PITYOPHILA; SOLVEX TAR