HEAT-PROOF AND ORNAMENTAL PAINTS.
Steam pipes, boiler fronts, smoke connections and iron chimneys are often so highly heated that the paint upon them burns, changes color, blisters and often flakes off. After long protracted use under varying circumstances, it has been found that a silica-graphite paint is well adapted to overcome these evils. Nothing but boiled linseed oil is required to thin the paint to the desired consistency for application, no dryer being necessary. The paint is applied in the usual manner with an ordinary brush. The color, of course, is black.
Another paint, which admits of some variety in color, is made by mixing soapstone, in a state of fine powder, with a quick-drying varnish of great tenacity and hardness. This will give the painted object a seemingly-enameled surface, which is durable and not affected by heat, acids, or the action of the atmosphere. When applied to wood it prevents rotting, and it arrests disintegration when applied to stone. It is well known that the inside of an iron ship is much more severely affected by corrosion than the outside, and this paint has proven itself to be a most efficient protection from inside corrosion. It is light, of fine grain, can be tinted with suitable pigments, spreads easily, and takes hold of the fibre of the iron or steel quickly and tenaciously.
Turpentine well mixed with black varnish also makes a good coating for iron smoke pipes.
Much brighter and more pleasant appearing engine rooms can be made by making the surfaces white. Lime is a good non-conductor of heat, and it has the further quality of protecting iron from rust, so it would appear that whitewash was as good a material with which to cover boiler fronts, smoke stacks, steam pipes, etc., as any other substance.
To prepare whitewash for this purpose it is only necessary to add a little salt or glue to the water used for dissolving the lime, as either of these substances will make it stick readily and it cannot afterward be easily rubbed off; but perhaps the best way to prepare the whitewash would be to boil a pound of rice until it has become the consistency of starch, all of the solid particles having been broken up by boiling, and add this solution to the solution of lime in water.
This last preparation is also very good for outside work, for after it has been applied and has an opportunity to dry, no amount of rain will wash it off and its appearance is almost equal to white paint, and no amount of heat ordinarily met with will discolor it, although the heat of the fire box doors, if it was applied in such place, would give it a brownish cast of color. Even the brick setting of a boiler looks very much better when nicely whitewashed than when of its natural color, and if the ceiling and walls of the boiler room are also whitewashed the effect is quite pleasing, more healthful and conduces greatly to cleanliness.
Any engineer who tries this, renewing the whitewash as frequently as he would paint, will give this plan of painting pipes and boiler front the preference over the use of any kind of black paint.