Protective Finishes
In Rural Building we have the following finishes which are applied on wood or masonry work:
- Oil paint
- Synthetic paint
- White wash
- Cement paint
- PVA Emulsion paint
- Varnish
OIL PAINT
The traditional type of oil paint has a vegetable oil base (linseed oil) and a pigment which gives It colour.
Oil paint is usually applied in three coats. Each coat is of a different composition and they cannot be mixed.
- Priming coat
- Undercoat
- Finishing coat
Follow the directions on the tin when using these paints. Oil paints can be diluted only with thinners, such as turpentine.
SYNTHETIC PAINT
Synthetic paints have a chemical base and a pigment. These paints dry more quickly than oil paints and they are more weather resistant.
Read the directions on the tin before using the paint.
WHITE WASH
White wash is often used for interior work. It is composed of lime and water and it is not water resistant. Its lack of water resistance and its poor wearing qualities make it inferior to emulsion paint as a finish for outside surfaces.
White wash is often used as a priming coat for emulsion paints. It fills in the pores in cement or plaster and makes the surface smoother so that less emulsion paint is needed.
After mixing the lime with water it is advisable to leave the white wash for a day to stand, to be sure that no more chemical reactions are taking place. Follow the manufacturer's directions on the label when mixing the white wash.
CEMENT PAINT
Cement paints are often used externally. They contain white or coloured Portland cement and are sold in powder form. This paint should be made workable with water only; when dry it forms a waterproof seal on the concrete or masonry.
PVA EMULSION PAINT
Polyvinyl acetate emulsion paint has a latex (rubber) base and a pigment for the colouring. This paint is used mostly for internal and external masonry work.
The latex paint can be diluted with water if necessary to improve its workability. The paint should be applied in thin layers and the directions on the label should be followed. Read them before you start work.
VARNISH
Varnishes are used to protect wood. There are two kinds of varnish: oil or spirit. Oil varnish can be used for external work. It is diluted if necessary with turpentine.
Spirit varnish is only used for internal work such as for furniture. This varnish is not very strong or water resistant. Spirit varnish can be diluted with commercial alcohol.
PAINTS AND VARNISHES: PURCHASING
Paints and varnishes are sold in containers of one or more litres. On each container there should be a description of how to apply the paint or varnish. There should also be a date stamped on the container, to indicate how long the paint or varnish will last (when it will be too old to use any longer).
