What are the characteristics of paints bases??
Characteristics of the more commonly used “bases “are discussed below:
This is a carbonate of lead and forms the base of lead paints. It is dense, permanent and water-proof. It is not suitable for delicate works as lead becomes discoloured when exposed to sulphur vapours. It is most suitable for wood surfaces; since it does not afford protection against rusting, it is not suitable for iron surfaces.
This is an oxide of lead and forms the base of lead paints. It is most suitable for painting iron surfaces and for providing a priming coat to wood surfaces. It solidifies in a short time with linseed oil and hence, it is used as a drier also.
This is an oxide of zinc and forms the base ofall zinc paints. It issmooth, transparent and non-poisonous. It is not decoloured when exposed to sulphurvapours. It is less durable and is difficult to work.
Oxide of Iron:
This is an oxide of iron and forms the baseof all iron paints. The tint of paint varies from yellowish brown to black. It mixes easily with the vehicle. It is effective in preventing rusting of iron surfaces and is cheap and durable. It is generally used for priming coat of iron surfaces.
This material possesses intense opacity.It is non-poisonous and provides a thin transparent film.