Stop knots from sabotaging your paint job! Bartoline Patent Knotting is a fast-drying, 500ml solution that seals knots and resinous areas in bare timber. This alchol-based lacquer with synthetic resins prevents sap bleed and ensures a flawless finish for your paints, waxes, or polishes. Apply it before painting doors, skirting boards, window frames, and more! Dries in just 5-10 minutes and lets you recoat after 30 minutes. Unlike traditional primers, Bartoline Patent Knotting won't be affected by natural tree sap or common paint thinners.