IMPROVES THE ADHESION OF FILLERS & COATINGS: WALL HARDENER is a stabilising substrate hardener with exceptional penetration. It hardens and stabilises loose or powdery substrates to significantly improve the adhesion of coatings and fillers. Can be applied over distemper. Moisture vapour permeable. Colourless. For use on interior and exterior surfaces. Ensure substrate is absorbent (porous) and dry before application. Can be painted in 24 hours.Fast penetratingStabilising hardenerHardens loose or powdery substrates