Manufacturer and builder ?, 1887
To prevent the disintegration of exterior brick or stone surfaces, caused by moisture of the atmosphere and change of temperature, paint should be used to cover the surface. Particularly in our Western cities do we find the stone gradually crumbling away, the same action taking place with the brick. The Process of decay is certainly slow, but it is sure. How often do we see magnificent stone or brick edifices gradually scaling and crumbling down, when by the application of a coat of paint the action could be prevented for years.
The great object is how and what to paint these surfaces with. In the first place, it is useless to ruin the outside appearance by an application of cheap trash which can be of no material benefit so far as preservation is concerned. It must be borne in mind that paints are mainly durable, and make the surfaces that they cover durable, because of the waterproof quality of the oil with which they are mixed.
The natural pigments — called others or earth Paints — do not in any degree act upon the oil; while others, such as white lead and the chromates of lead, do affect the oil chemically, and impair in a measure its tenacity and waterproof quality. For these reasons it follows that the natural pigments are not only the most economical, but also the most durable for Painting brick or stone houses.
It has been demonstrated that the most durable Paint for brick or stone houses is finely ground French ocher, mixed in proportionate quantities with white zinc. The color produced is a soft shade of buff, most pleasant to the eye and permanent to the last degree, both in color and material.
Venetian red, an artificial ocher or red oxide of iron, is in common use, but it does not hold oil like ocher, and makes a coating far less water proof. It is a seemingly durable paint, because the stain which it imparts to a porous surface remains long after the oil has washed away. It cannot be used with zinc, because of the unsuitable color which it produces, and because this pigment (Venetian red) when tinted with white becomes highly fugitive in color.
The condition of the wall is also very important in painting brick or stone surfaces. The work should be done in warm, dry weather, when the moisture which the bricks or stone absorb during the winter and spring seasons has dried out, otherwise the paint will not be apt to adhere tenaciously, but will scale or peel off. The joints require constant looking after in the coping. These should be made absolutely impervious to water by the application of soft putty in a mass both on the top and the edges, and when this hardens to the point of cracking, it should be renewed. Mortar and cement for such purposes are useless, for no matter how water proof the surface may be, if the water be allowed to percolate through the joints, the integrity of the wall will be destroyed.
The first coating of paint for brick or stone should be mixed very thin, more as an oil stain than as a paint, to allow the brick to absorb all that is possible. By being thin, moreover, the paint readily runs into cavities that thicker material would not penetrate. The second coat can be used heavier in body. Then by the application of one coat every few years a building would last indefinitely, and the owner would feel that his building was proof against atmospheric changes.
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