Blocking Primer is a protective primer. It is for surfaces sensitive to acids where application of Rust Spirit, Copper Spirit or Bronze Spirit is used. Blocking Primer protects the surface from acid attack, preventing wood’s tannins from bleeding into the finish. It also prevents the “softening” of sensitive plastics. Ideal uses for Blocking Primer Wood high in tannin content (Oak, Chestnut, Cedar etc) Use on plastics sensitive to acid to avoid softening Can be used on interior or exterior surfaces Before you start Cover and protect everything you do not wish to coat. Apply between 5°C and 25°C. Do not apply to hot surfaces. Surface Preparation Surfaces must be in good sound condition, clean, dry and free of all grease, oil and other surface contamination. Meticulously clean surface using a suitable cleaning agent depending on the substrate and contamination. Allow to dry. Sand bare wood surfaces with 80-100 grit paper. Thoroughly dust off. Prime plastics (except Polyethylene and Polypropylene) with Absolute Primer. Application of Blocking Primer Use as is. Do not thin. Stir or shake well before use. Apply a coat of Blocking Primer. Allow to dry. Finish with a product from the Owatrol spirit range Clean Up Soap and water.