|CLICK HERE FOR INDEX PAGE|
|REVISION CARDS - PAINT FINISHES TO WOODS|
|V.Ryan © 2018|
|PDF FILE - CLICK HERE FOR PRINTABLE WORKSHEET|
|PAINT AS A FINISH
Paint is basically the same as varnish, although it contains coloured pigments. Paints are applied with a brush or spray gun and add a protective layer to the surface. Paints are available as matt, silk and gloss finishes and they are either water based or oil (solvent) based. Unlike many other finishes that enhance the natural grain of the wood, paints hide the grain.
|PRIMERS, UNDERCOATS AND TOP COATS
Paint primer is required to seal the wood, so that there is a stable base for the application of the next paint, which is undercoat.
Undercoat is supplied in a restricted range of colours and is selected according to the colour of the final top coat. The undercoat blocks all blemishes, grain and marks, providing a blank canvas for the top coat.
The top coat provides the final finish, in terms of the colour and whether it is matt, silk or gloss.
|WATER BASED (ACRYLIC EMULSIONS)
OR SOLVENT (OIL) BASED?
Water based paints (acrylic paints) are environmentally friendly. They dry more rapidly and do not produce the odour associated with solvent based paints. After use, brushes and equipment can be cleaned in soapy water.
Solvent based paints are more damaging to the environment and the health of humans. Brushes and equipment have to be cleaned with thinners or white spirit. When drying, the solvents evaporate, releasing volatile organic compounds (VOCs) into the atmosphere.
|1. What is the difference between paint and varnish? 3 marks|
|2. What is the difference between water based and solvent based paints? 5 marks|
|CLICK HERE FOR RESISTANT MATERIALS INDEX PAGE|