Paint and Varnish Facts and Formulae; A Hand Book for the Maker, Dealer and User of Paints and Varnishes

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...or other sources, until at length, the coating loses its binding qualities, and the varnish or paint disintegrates and perishes. The duration of the life of the coating will depend on the quality of the drying oil and the action or non-action of the resins or pigments with which it is combined, also by the proportion of oil used. The greater the proportion of oil, the more lasting the coating will be. Metals, being non-porous, and having the paint entirely on the surface, the coating is shorter lived than on more porous substances. Of the other agencies which work destruction to the oil may be mentioned rain, fog, and snow, air currents, dust, dirt, or sand, smoke gases and the nature of the pigment used. The practical life of paint on metal work exposed to the elements is scarcely more than two years, while on wood or plaster, five years is the most that can be reasonably expected. The action of rain, snow and fog, aided by wind currents, can be readily understood by observing the side of a house which is exposed to the quarter from which prevailing storms come. Wind will also drive dust and sand with more or less force against the protected surfaces and the mechanical action of such substances is much the same as that of the sand blast, though, of course, far less severe. The action of smoke gases, as has been mentioned before, is of a chemical nature, due to the formation of sulphurous acid from the chemical action of the gases, and steam, which rapidly attacks the oil binder. The action of certain pigments on the oil is very marked and has been previously referred to. Eed lead forms a hard solid coating when combined with drying oil, due to chemical action of the pigment in causing a more rapid oxidation, or drying of the oil and the added fact, that in...