Achieve a Flawless Finish with Ronseal Knot Block Wood Primer and Undercoat. Apply this primer & undercoat from the Ronseal Knot Block range to interior wood surfaces using a brush to prepare them for painting. It takes 2 hours to dry and will cover up to 12 m² per litre on average. This product completely stops wood knots and wood resins from showing through your paint. It also covers bold colours and dark marks, and helps your paint to stick. Provides a flawless finish that won't yellow, crack, or peel. Perfect for knotty wood like pine. Weight: 7.2 pounds, Manufacturer: Ronseal