Penta Undercoat (Gallon)

General Surface Preparation

Ensure that all surfaces are dry and cleaned free of all dirt, dust, grease, oil, wax, fungus/algae and other contaminants which may affect adhesion, protective properties or appearance of the coated surface.

Solvent Cleaning: Oil, grease and wax can normally be removed by using Penta Thinner 41 and changing wiping cloths often to assure removal.

Treatment for Fungus/Algae Infection: Clean infected areas with a solution of 1 part household bleach in 3 parts water (and 1 spoon detergent) using a sponge or brush. Rinse off thoroughly with clean water. This may be repeated in severe cases. Observe manufacturers Safety Precautions for using household bleach. Wear protective goggles, rubber gloves, boots and clothing to protect eyes and skin.

New Wood: New wood must be properly cured, dry and free of all contaminants, including exuded resin and salts arising from preservative treatment, by cleaning with Thinner 41 and/or water.
Fill all holes, cracks, splits and crevices with an appropriate putty or filler. Oil based putties or fillers should be used over primed wood.
If creosote or coloured metallic napthenates (e.g. copper napthenate), which bleed through most paints, have been used to treat lumber, they must be weathered off the surface prior to application of paint.

Fibre Building Boards: (Softboard, mediumboard and hardboard). Sanding is not usually necessary and can damage glossy-surfaced hardboards. Fill nail holes and other surface defects with an appropriate putty or wood filler. Oil-based putties and fillers should be used only on primed and sealed surfaces, and water-based on either.

Chipboard: Single layer, open-surface chipboards may require sanding and overall filling with oil or water-based fillers if a high standard of finish is required, but must be primed first with an oil based primer, such as Penta Wood Primer Undercoat.

Ply Wood: As for solid wood including cleaning, sanding and treatment of knots (although knots are rarely a problem), stopping and filling. If checking has occurred on exterior plywood which is to be painted, it must first be filled after priming.

Previously painted: Remove all loose, flaking, peeling and semi-adherent paint, sanding to a featheredge where necessary, to obtain a clean, firm surface. Remove dirt, chalky residue, oily contaminants. Wash protected areas around eaves, porches and recesses not normally flushed by rain, to remove surface layer of soluble salts. Treat fungus/algal infection. Glossy surfaces must be dulled by sanding. If more than 25% of the previous coating has failed, or can be easily scraped off the surface, it should be completely removed.

Surface Preparation: Ensure that all surfaces are dry and cleaned free of all dirt, dust, grease, oil, wax, fungus/algae and other contaminants which may affect adhesion, protective properties or appearance of the coated surface.

Solvent Cleaning: Oil, grease and wax can normally be removed by using Penta Thinner 41 and changing wiping cloths often to assure removal.

Treatment for Fungus/Algae Infection: Clean infected areas with a solution of 1 part household bleach in 3 parts water (and 1 spoon detergent) using a sponge or brush. Rinse off thoroughly with clean water. This may be repeated in severe cases. Observe manufacturers Safety Precautions for using household bleach. Wear protective goggles, rubber gloves, boots and clothing to protect eyes and skin.

New Wood: New wood must be properly cured, dry and free of all contaminants, including exuded resin and salts arising from preservative treatment, by cleaning with Thinner 41 and/or water.
Fill all holes, cracks, splits and crevices with an appropriate putty or filler. Oil based putties or fillers should be used over primed wood.
If creosote or coloured metallic napthenates (e.g. copper napthenate), which bleed through most paints, have been used to treat lumber, they must be weathered off the surface prior to application of paint.

Fibre Building Boards: (Softboard, mediumboard and hardboard). Sanding is not usually necessary and can damage glossy-surfaced hardboards. Fill nail holes and other surface defects with an appropriate putty or wood filler. Oil-based putties and fillers should be used only on primed and sealed surfaces, and water-based on either.

Chipboard: Single layer, open-surface chipboards may require sanding and overall filling with oil or water-based fillers if a high standard of finish is required, but must be primed first with an oil based primer, such as Penta Wood Primer Undercoat.

Ply Wood: As for solid wood including cleaning, sanding and treatment of knots (although knots are rarely a problem), stopping and filling. If checking has occurred on exterior plywood which is to be painted, it must first be filled after priming.

Priming: Prime with 1 or 2 coats Penta Wood Primer Undercoat, depending on the texture and porosity of the surface, prior to finishing coat being applied, and depending on quality of finish required.
Fire-retardant treated fibre building boards (soft, medium and hardboards) must be sealed with Penta Acrylic Sealer.
Redwood, Red cedar or other woods – which contain natural water-soluble dyes, should receive 2 coats of Penta Wood Primer Undercoat, prior to application of a latex paint.

Finishing: Refer to relevant product data sheet.