New plywood has an abnormal porosity which allows the intrusion of fungal spores, carried by environmental moisture. This is why plywood rots more readily than solid wood siding.

     This material was treated with Clear Penetrating Epoxy Sealer™ (CPES™) dyed blue, so that regions of abnormal porosity would be visible after impregnation. The bottom edge was placed in a shallow tray and the liquid wicked up into the wood. After impregnation and cure, a few sections were cut and sanded.

     The dyed resin shows regions of abnormal porosity. These regions are now impregnated with a highly rot-resistant and water-repellent resin. This treatment improves the ability of the wood to resist further deterioration. When finally painted, the CPES glues the paint to the wood, so paint sticks better and lasts longer.

     These plywood specimens were completely saturated first with CPES. 48 hours later, the bottom edge was placed in a shallow tray containing CPES with a blue dye added, and the liquid wicked up into whatever porosity there might now be. After this treatment and cure, a few sections were cut and sanded.
     The dyed resin shows regions of abnormal porosity remaining after the impregnation treatment. You will note the tremendous reduction of abnormal porosity compared to the upper specimen. This is why wood treated with Clear Penetrating Epoxy Sealer resists rot so well.

© copyright Steve Smith, 1972 - 2015, All Rights Reserved.