Preparation for painting
Before you start any painting project you will need to inspect the surfaces to determine what types of finishes or products have been previously used to help you select the correct primer, sealer, base or topcoat required.
Previously painted
If you are painting over a previously painted surface, ensure that all dirt is removed by scrubbing with sugar soap. If the surface was painted with oil-based paint, you must either lightly sand down to provide a 'key' (good surface for the paint to adhere to). 180- or 240 grit sandpaper is the best to use for this.
Interior timber
All wood needs to be lightly sanded before painting. Sand along the grain to prevent scratching the timber and raising fibres. Remove all dust and dirt before painting.
Make good any repairs before you apply primer and paint. Acrylic sealer fills and smoothes out the joints where two surfaces meet and can be painted over. If timber is in poor shape sand with 120-grit sandpaper. Smooth with 180- or 240-grit sandpaper.
Plasterboard or drywall
Any joints should be sanded smooth with either 180- or 240-grit sandpaper. Wipe the area with a slightly damp cloth to remove dust. Plasterboard and drywall can be primed with a watered down solution of paint, or a base coat primer can be used.
SupaWood (MDF)
Wipe clean with a damp cloth to remove any dirt. It is possible to paint directly onto Supawood without a primer, but it will need an extra coat. It's also essential to sand the cut edges of SupaWood with 220-grit sandpaper until smooth. This assists in blocking the edges so that they do not absorb too much paint. If you are spray painting SupaWood, sanding is important. Alternatively, apply a light coat of wood filler over the cut edges, let dry and then sand smooth before painting.
Melamine or Laminate
You can paint over both melamine and laminate. Before painting, use an random orbit sander the de-gloss the surface and provide a better key for the paint. To do this, sand with 180- or 220- grit sandpaper until the gloss finish has dulled.
All-in-one primer
Prominent Ultraprime is a high performance, superior quality water-based primer formulated for interior and exterior use on metal, wood, walls, SupaWood, plaster, ceramic tiles, rigid PVC and ceilings. It provides an extremely smooth base coat for subsequent painting. It also contains fungicide to eliminate fungal growth.
Galvanised Steel
New metal should be thoroughly degreased by wiping with mineral turpentine. Structural galvanised steel (pipes, beams, hand rails etc) must be sanded down to remove chemical treatments from the surface and ensure adhesion of coatings.
Iron and Steel
If no rust is present, the surface should be thoroughly degreased by wiping with mineral turpentine and fine steel wool. Loose rust can be removed with a wire brush or multi sander and then treated with Rust-Oleum Stops Rust Primer before painting.
GOOD TO KNOW
On steel window frames, check the surrounding seals for damage and replace where necessary. Use an acrylic sealer to fill any gaps before painting.
Clay and face bricks
Remove loose particles by dry brushing the surface down. Fill holes and cracks with a masonry filler. Wash the surface if necessary with a solution of water and household detergent. Rinse with water and allow to dry.
Concrete and Cement
Concrete and cement must be completely cured before any preparation is done. New concrete may be wet under the surface and this moisture may later cause blistering and peeling of paint. Concrete and cement should be allowed to dry for 4 weeks. If necessary, wash with a solution of water and Jik to achieve a clean surface before painting.
Plaster
Leave to cure for 28 days prior to painting. Fill cracks with a suitable plaster filler and smooth the filler by lightly sanding. Apply a suitable primer for plaster surfaces before painting.
Tiles
It is essential to do the proper preparation before painting over tiles to ensure a good surface for the paint to adhere (bond) to. Clean the tiles and grout with sugar soap to remove all traces of dirt and grime. This is especially important in a kitchen, where grease tends to leave a thin, almost invisible layer over the surface of the tiles and grout. For gloss tiles you will need to de-gloss the surface by sanding with 180-grit sandpaper, or using an orbital sander. Wipe clean to remove all traces of dust.