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.