Paint such as is most frequently used is the material used for painting
buildings, such as houses, barns, stores, and many others which we need
not mention here. This paint is used on these buildings mostly for two
very important reasons--one being to beautify the buildings, the other
being to protect them from the ravages of the weather, much in the same
way that your clothes protect you from the weather.
Paint such as we mention here may be regarded as the most simple
and useful form. You have no doubt frequently seen the painter-man
spreading paint on some building, or perchance, you have seen your
father doing it, and have noticed that paint is a fluid substance
looking something like cream, which is applied to the surface to be
painted with a suitable brush and is brushed out smoothly. After the
first coat is dry, other coats are put on in the same way until enough
paint has been put on to thoroughly hide the unevenness of the lumber
and making it of a uniform color.
This paint is made by simply mixing together dry powder, which is
usually called pigment, with a thin, yellowish liquid which is called
linseed oil. In the earlier days, the painter-man mixed this paint
himself whenever he desired to use it. In these more modern times, he
usually buys this paint already prepared.
Perhaps a little history of the preparation of the package of a can of
paint which he buys may be interesting to you.
Let us imagine that the can of paint is white. In this case, the
pigment which is used is a white powder and is made of either metallic
lead or metallic zinc. The preparation of this fine white powder is
very interesting and requires considerable time to perfect.
Let us consider the pigment known as white lead first. This is produced
by causing metallic lead, which is of a bluish-gray color and very
heavy, to change from its original form by a process which is known
as “corrosion.” This corrosion is brought about by first taking the
metallic lead, which at this stage exists in large pieces known as
“pigs.” These pigs of lead are melted in a furnace and then molded into
small, thin shapes which are buckles.
[Illustration: HOW WHITE LEAD IS MADE