Reinforce decayed wood fast with Wet Rot Hardener. Use Ronseal Wood Hardener to bind and harden decaying wood and provide a solid base for filling. It'll make your wood hard again, ready for you to repair with a 2 part wood filler. It penetrates deep into the wood and cures wood rot on any timber surface. Reinforces wood and sets rock hard. Quick-drying. For interior and exterior use.