TREATMENT OF 8 4 HARDWOOD LUMBER WITH BORATE PRESERVATIVES/

The minimum diffusion storage time required for adequate diffusion pen etration of berate, the effects of berate formulation and wood species on initial loading and subsequent berate diffusibility, and the relat ionship between wood liquid permeability and berate diffusibility were studied. Packets of thirty-five 2 by 4 studs sawn from yellow-poplar, red oak, white ash, and white oak were dip-treated for 1 minute in Di ffusol(R) and Tim-Bor(R) solutions. Treated packets were wrapped in pl astic covers and stored for diffusion under a shed and sampled after 2 0 hours, and 2, 4, 6, and 8 weeks. Results indicated that more than 8 weeks of diffusion storage are needed for an adequate berate penetrati on for all four species. Diffusol reaches a higher core boric acid equ ivalent than Tim-Bor for a given diffusion time. Diffuse-porous wood t reated better than ring-porous wood, and berate penetration into these samples was more closely related to radial permeability than longitud inal permeability.