Cuprinol Wood Preserver Clear 1 litreCuprinol Wood Preserver is a water based, colourless, general purpose preserver for interior* or exterior use. It gives deep penetrating protection to sound wood against decay, mould and blue staining fungi. Before application remove excessive dirt and soiling, large areas of algae, lichen or fungi using an appropriate fungicidal wash or cleaner designed for the job. Wood that has been wood stained, painted or vanished should be stripped back to bare