Bird Brand Superior Clear is both a wood preserver and a woodworm killer. It is water-based and dries clear, making it perfect for overcoating with paints and primers. Equally, it can be left unfinished or used just to kill woodworm. Superior Clear Wood Preserver contains 3 active ingredients that are designed to prevent and eradicate wood-boring insects, mould, dry rot and wet rot. Being water-based the product still penetrates but is much more pleasant to use and virtually odourless.