An investigation was made to determine the relative performance of three readily available inorganic chemicals containing either copper or chromium when applied singly or in combination to sawn coconut timber surfaces. The treating solutions, consisting of chromic acid (H₂CrO₄) sodium chromate (Na₂CrO₄) and copper sulphate (CuSO₄), were applied by trush to wood surfaces with one coating at the rate of approximately 155 grams per square meter. The specimens were exposed outdoors on racks inclined at 450 angle and facing south.

            Results after 3 years of test showed that treatments with mixture of H₂CrO₄ and CuSO₄ or combination of Na₂CrO₄ and CO₄ performed better than single application of either H₂Cr₄ or Na₂CrO₄. The former treatments still showed uniform and pleasing appearance after the exposure period.