The Washington times., 1922-09-30
USE Of VARN|SH
. IS BIC FACTOR
|NAUTOUPKEEP
Writer in Motor Age Gives
Facts for Dealers and
Public.

The use of varnish as a protective
coating dates back thousands of
years. The Oldest in existence is
supposedly on Egyptian mummy
cases whose ages are some 1900
years. Analysis show II to be a COM
pound of drying oil and resin-in
other words. similar to the best made
today. All OF which goes to show
what may be expected of good var.
nish; and when II Is said that the
average life of finishing varnish on
an automobile Is about one year, the
contrast becomes pronounced writes
G.. King Franklin in motor Age"
OF course, the mummy cases were
kept inside and protected, while the
automobile is subjected to all sorts
OF everyday abuse, but nevertheless.
the comparison shows that the life
of varnish can be prolonged by giving
it proper care.
The requirements of the present
day finishing varnishes are so varied
and eXacting that their production
represents the best of the Varnish
makers art. They must meet the
needs Of modern shop practice in
drying rates and ease Of application
decorate the surfaces by imparting
to them a high luster, and at the
same time protect them from with.
out.
How successfully a finishing var
nish does this. and for what extent
OF time. depends not only upon the
varnish itself and the conditions of
the paint coats beneath 1t, but also.
and to a large degree, upon the care
and attention given to II by the car
owner. The purpose of this article
Is to tell you something about finish.
ing varnish and its weaknesses.
Two Main Varnishes.
There are two main types Of var.
nishes-spirit and oleo.resinous. In
the former a resin.li shellac, rosin,
dammer, etc, Is dissolved in q vola-
tile solvent like alcohol, benzine, etc,
and when the solution Is spread out
over a surface the volatile solvent
evaporates leaving the nonvolatile
resin spread out in a uniform film.
The solvent has acted as a mechani-
cal means of evenly distributing the
resin. This resinous film Is brittle
and possesses no wear resisting quail
tiles such as characterizes the latter
type.
Shellac is a type of spirit.varnish
familiar to all. The oleo-resinous
varnishes are, as their name implies,
largely composed of drying oils and
resins. The use OF the drying oil in
sufficient quantity imparts to the
film an elasticity which allows II to
withstand wear and exposure. and
the proper resins impart to 1t a cal
culated amount of hardness and its
high luster.
The elasticity and hardness Of the
film can be regulated by varying the
proportions OF resin and oil. II a
hard, tough film is desired, suited
for rubbing down, the proportion
of resin to oil may be as high as
to 1, although in the slower drying
materials this may be a : low as l TO
/. II a tough, elastic dlm is de-
sired, possessing wear-re Sting quail.
tiles, more oil Is used VI. Nthe pro-
portion becomes as high to o
that is l part OF resin to OF oU.
The oil furnishes elasticity and dura-
bility and the resins hardness and
brillianCy. The first type is known
as rubbing varnish and the latter
as finishing varnish.
Practically all of the resins used in
the manufacture OF these oleo.resin-
Gus varnishes are OF vegetable origin.
obtained from fossil deposits Of the
saps of trees. AS now used, copal
is the general term that includes
all of the five main types-East
African, West African, Manila,
hni
main difference lies in their varying
degrees Of hardness, and as rule
the harder the resin the better the
price 1t commands.
Qualifications Of Linseed.
The most popular drying oil is
linseed oil. and this popularity Is
due to the fact that il combines
readily with resins and will itself
dry to a tough, leathery film possess.
ing wear.resisting qualities and SOL
uble only in strong acid or alkali.
The so-called drying oils. such as
linseed Oil, are distinguished from
the non-drying oils by the fact that
the former oxidize and harden when
exposed to the air.
Were it not for the drying oils
there would be no such paint or
varnish. as 1t is their oxidized film
that furnishes the protective coat
ing. Tung oil Is another important
one. but the rest, such as soya bean.
fish. corn. etc, are used chiefly
as adulterants Of the higher priced
linseed.
While the oil and resin may be
said to play the leading roles. there
are two other materials used in the
manufacture Of these oleo.resinora