Preservation and Materials used for Preserving Wood

Explain wood preservation and the materials used for preserving the wood.

Preservation and Materials used for Preserving Wood

Wood preservation is a very important aspect of the study of timber technology for increasing the life of wood. It is always better to keep the wood dry. Timber should be preserved from white ants which are most destructive for wood. Hence the proper preservation of wood should be observed by applying suitable types of oils or chemicals on the wood.

Following types of materials are commonly used of preserving the wood.

(i) Oil type

(ii) Water soluble type

(iii) Solvent type

(i) Oil type

Oil which are named as creosotes are obtained from distillation of coal tar or wood tar. Creosotes are widely used for exterior use on railway sleepers and piles etc. The timber which to be painted is not treaded by creosotes.

(a) Coal Tar Creosote

This oil is heavier than water having black or brownish color. It stains and does not take paint well, so its use is limited.

(b) Coal Tar

It is highly viscous and is applied always hot.

(c) Carbolineum

It is a strong antiseptic and disinfectant. It penetrates the timber by its own action. It is applied with brush. It save the wood from white ants and prevents dry rot.

(d) Solegnum

This protects the timber from the attack of white ants. It can be mixed up with pigments of different shades to make the treated timber attractive in appearance. It Is applied hot with a wire brush.

(ii) Water soluble type

These include zinc chloride as the most commonly used wood preserve. It is adopted for protection of roofing timbers where there Is a high humidity and of timber in mines to reduce the risk of fire. Sodium Fluxed is more costly than zinc chloride but is highly toxic to fungi. “Copper Sulphate” is very toxic to fungi. Its high solubility in water makes it a temporary preservative. “ASCU’ treatment is a new preservative which has been developed at the Forest Research Institute.

(iii) Solvent type

These are generally include the copper and zinc salts, dissolved in spirit. The oils evaporate after the timber has been impregnated the toxic compounds are left in impregnated condition in timber. These are clean and permanent and in most cases the treated timber can he painted, waxed or polished. These are prayed or coated easily but these are rather costly.