Where the Existing Coating is Unsound
All of the loose, unstable coating must be removed before repainting. Sand the areas of old, unstable paint with 80 to 120 grit or 180 to 240 grit abrasive paper to remove all loose and unstable areas and refresh the surface. Where the unsound coating meets sound existing paint, feather the edges of the sound paint with 180 to 240 grit paper, then lightly sand the surface of the sound paint to enable the new coating to key to it. The surface should be wiped down with a damp cloth to remove any remaining dust and residue. Where needed, apply a filler to smooth out holes and imperfections in the surface. Re-apply the entire prepcoat and topcoat paint system, as recommended for that particular substrate.
Re-apply the entire prepcoat and topcoat paint system, as recommended for that particular substrate.
Where the Existing Coating is Sound (and Acrylic)
The existing acrylic coating should be scrubbed down with an oil-free detergent such as Sugar Soap (normal dishwashing liquid is not good for this), to remove any stains or dirt. Once cleaned, the surface can be lightly sanded with 180 to 240 grit paper, and wiped down with a damp cloth to remove dust and cleaning residue. Apply 2 coats of a quality acrylic topcoat as specified in the topcoats table for that particular substrate.
Where the Existing Coating is Sound (and Oil-Based)
The existing oil-based coating should be scrubbed down with an oil-free detergent such as Sugar Soap (normal dishwashing liquid is not good for this), to remove any stains or dirt. Once cleaned, the surface can be lightly sanded with 180 to 240 grit paper, and wiped down with a damp cloth to remove dust and cleaning residue. A quality acrylic or oil-based primer sealer undercoat should be applied to the surface, followed by 2 coats of a quality acrylic or oil-based topcoat, as specified in the topcoats table for that particular substrate.
Where the Existing Coating is Sound (and Stained / Clearcoated Timber)
If the existing coating is a stain or clear-coat applied to timber, the entire area should be scrubbed down with an oil-free detergent such as Sugar Soap (normal dishwashing liquid is not good for this), to remove any stains or dirt. Once cleaned, sand the coating with 80 to 120 grit or 180 to 240 grit abrasive paper to create a roughened surface to promote adhesion of the new coating. The surface should be wiped down with a damp cloth to remove any remaining dust or cleaning residue. A quality acrylic or oil-based prepcoat should be used, followed by a quality acrylic or oil-based topcoat as specified in the topcoats table for that particular substrate.