Cuprinol Woodworm Killer (WB) kills all types of wood-boring beetle larvae. Its deep penetration ensures effective protection for years to come. This low odour, water-based formula has been specially developed to make it more pleasant and convenient to use. Application: Bare Wood: Flood surfaces with 2 or 3 brush coats. Pay particular attention to endgrain, corners, joints, crevices, etc. In severe cases, also inject into flight holes 7-10cm (3-4ins) apart and repeat treatment. Re-treat surfaces cut after treatment. Polished Wood: Inject into flight holes 5-7cm (2-3ins) apart. Flood into joints. Wipe off surplus. In severe cases repeat treatment. Fluid does not penetrate polished surfaces. Wax polished surfaces will normally require re-waxing after treatment. Note: The application of this product may cause darkening of some timbers. If colour is critical, try a test area first and allow to dry fully to ensure final appearance is acceptable. After drying, glues, fillers and knotting can be used normally. Bitumen, rubber and some plastic based materials may soften or swell on contact with fluid or solvent vapour.Do not spill on asphalt, bitumen, bitumen felt, tar or mastics. Ensure timber is fully dry (allow 6-8 weeks) or use a vapour barrier such as heavy-duty polythene sheets (as used for damp proof membrane) before laying plastic floor tiles, foam or rubber-backed carpet, underlay or hanging vinyl wallpaper.