Page 24 - Curriculum Visions Dynamic Book

Lead in paint and glaze
A paint is a liquid that is applied to a surface to protect it
and to give it a colour. A paint is made up of solid colouring material – known as a pigment – mixed into a liquid that
allows the pigment to be applied with a brush or spray gun. When it is applied, the liquid evaporates or reacts chemically with the surface, leaving the pigment behind as a thin solid film.
One of the most common pigments used in paint was white lead; a general term for a range of white lead pigments such as lead carbonate, lead sulphate and lead silicate. For many years, it was used in interior gloss paints and in exterior paints; but because of the possibility that very young children might eat the paint, it is no longer used for interior or domestic purposes.
The other coloured oxides of lead have also been widely used. Red-leaded paints are still used for exterior applications because lead oxide and lead silicates are so stable they resist corrosion even in the most exposed places. Red lead is still widely
used as a metal-protective undercoat.
 Red lead being applied as a protective coat after a rusty part has been stabilised with phosphoric acid.
24