Tanalising

Tanalising is simply the process of where a highly toxic blend of copper and arsenic is vacuum pressure impregnated into softwood and is used as a preservative. This treatment process ensures deep penetration into the timber cells, for a longer lasting protective result against fungal decay and insects than the application of a surface coating.

The stages of tanalising

1) The tanalising process involves placing the timber in to a treatment cylinder and creating a vacuum withing the timber vessels.

2) The cylinder is then flooded under vacuum with the preservative treatment

3) Hydraulic pressure is applied forcing the preservative deep into the timber and its cells

4) After a pre-determined period of pressure depending on the species of the timber being treated and its use, the treatment solution is pumped back into storage and a final vacuum extracts any excess treatment solution

5) Finally, low pressure inside the timber draws the surface solution when vented to the atmosphere and the treated timber is left for a specified period for fixation of preservative to occur.

Tanalised timber does not need any further maintenance treatment but will naturally weather over the months finally changing to a grey colour. This is caused by the effect of sun, moisture, wind and other exterior conditions. The timber will produce cracks  that will open and close as an effect of condition changes. They are not detrimental to the long term durability of the product.


Here are pictures illustrating the process of tanalising.