Sound painting practice, paint coatings are composed of different chemicals, which combine synergistically to provide the paint with its properties. However, in order to derive the optimum paint properties and maximise the longevity of the coatings, it is of paramount importance that the paint coating is applied using best painting practices and according to the manufacturer’s specifications. In the main, it is essential that the substrate to which the paint coating is applied is free of defects that will affect the adhesion of the coating system.
Adhesion to the substrate is the key to coating longevity in sound painting practice. In addition, it is important to use a paint coating system that will protect the building substrates and enhance the aesthetics of the building.
The repair, removal, cleaning and general preparation of the substrate is essential, this is required prior to the painting of new and existing plaster, concrete, brickwork, and building boards.
Exterior
If painting from corner to corner is not done, the following problems may result:
1)Where newly painted walls have been damaged, the same principle applies as for the redecoration of existing surfaces: Where touch-ups are done on a wall, there will be a colour difference due to the extra depth of colour on that one spot.
2) The touched-up patch will also stand slightly proud on the walls, which will result in an uneven appearance. Furthermore, light reflection on uneven surfaces will result in sheen differences.
3) Touch-ups and patching are usually done with a brush and these brush marks will contribute to the difference in appearance, against a background where a roller was previously used.
4) The effect of touch-ups and spot-patching will be made worse in cases where a crack filler has been used on damaged areas – touching up/patching without a sealer/primer will result in a dull, rough appearance where the crack filler has absorbed the binder in the topcoat.
Interior
1) Touch-ups and patching are usually done with a brush and these brush marks will contribute to the difference in appearance, against a background where a roller was previously used.
2) The effect of touch-ups and spot-patching will be made worse in cases where a crack filler has been used on damaged areas – touching up/patching without a sealer/primer will result in a dull, rough appearance where the crack filler has absorbed the binder in the topcoat.
3) To avoid an effect known as picture framing, cutting of corners and edges should always be followed by rolling.
Please bear in mind that the appearance of a colour can depend on the type of lighting. Therefore, check the colour in actual lighting conditions that will be used.
Very Important – If repainting from corner to corner is not a viable option, we recommend that the Paint Distributor eye-match the existing colour on the walls. A better colour match will be achieved if paint from the same batch is tinted and boxed. Please bear in mind that the appearance of a colour can depend on the type of lighting. Therefore, check the colour in the actual lighting conditions that will be used.
When Touching up, the following needs to be considered:
Touching-up must always be done from corner to corner and from top to bottom. This is particularly pertinent in exterior products that are older than two years where use of the original colour paint for touch-ups may show colour differences.
EastCoat professional painting contractors subscribe to these principals.
When establishing a sound surface prior to painting the main areas to be addressed are as follows:
Remove mould and mildew
Mildew comprises minute fungi which forms a white, yellowish, brown or black coating on damp surfaces. Since it can actually feed off some of the organic compounds in paints, it’s not a good idea to paint over mildew. To kill it off, mix up a solution of one part bleach to ten parts water and scrub walls using a wire brush.
Thoroughly clean exterior walls
Dirt and other debris collects on walls, as a result of exposure to the weather, and this can cause poor adhesion of the paint to the wall surface. Hose the walls down, or use a high pressure cleaner for stubborn dirt and mildew.
Remove loose paint
First, use a paint scraper to strip off loose paint from the walls. Going over the walls with a wire brush will remove the last remnants of flaked or chipped paint.
Repair cracks in walls
Fill in cracks and holes with an exterior filler. Exterior filler dries off with a smooth finish – don’t leave it this way, though, since your repairs will be obvious when painted. To match it to the plaster work, stipple with a stiff brush or roughen with a rag, so that the filler has the same texture as the surrounding paint.
Sand wood and metal areas
For wooden surfaces, doors or window frames – use sandpaper to remove old varnish and paint. Use emery paper to do the same on metallic surfaces.
Use a plaster primer
Good quality primers act as sealants on porous surfaces, and help paint properly bind to surfaces.
Paint dry walls only
