Produced by Chris Curnow, Harry Lame and the Online
Distributed Proofreading Team at https://www.pgdp.net (This
file was produced from images generously made available
by The Internet Archive)
+------------------------------------------------------------------+
| TRANSCRIBER'S NOTES |
| |
| * Where the original work uses text in italics or bold face, this|
| e-text uses _text_ and =text=, respectively. Small caps in the |
| original work are represented here in all capitals. Subscripts |
| are represented as _{subscript}. |
| * Footnotes have been moved to directly below the paragraph or |
| table to which they belong. |
| * Several tables have been split, transposed or otherwise re- |
| arranged to make them fit within the available width. |
| |
| More Transcriber's Notes will be found at the end of this text. |
+------------------------------------------------------------------+
PAINT TECHNOLOGY AND TESTS
Published by the
McGraw-Hill Book Company
New York
Successors to the Book Departments of the
McGraw Publishing Company Hill Publishing Company
Publishers of Books for
Electrical World The Engineering and Mining Journal
Engineering Record American Machinist
Electric Railway Journal Coal Age
Metallurgical and Chemical Engineering Power
PAINT TECHNOLOGY
AND TESTS.
BY
HENRY A. GARDNER
_Assistant Director, The Institute of Industrial Research,
Washington, D. C._
_Director, Scientific Section, Paint Manufacturers' Association
of the United States, etc._
McGRAW-HILL BOOK COMPANY
239 WEST 39TH STREET, NEW YORK
6 BOUVERIE STREET, LONDON, E.C.
1911
_Copyright, 1911, by the_ MCGRAW-HILL BOOK COMPANY
THE.PLIMPTON.PRESS.NORWOOD.MASS.U.S.A
TO
MY MOTHER
PREFACE
A few years ago the producer and consumer of paints possessed
comparatively little knowledge of the relative durability of various
pigments and oils. There existed in some cases a prejudice for a few
standard products, that often held the user in bondage, discouraging
investigation and exciting suspicion whenever discoveries were made,
that brought forth new materials. Such conditions indicated to the more
progressive, the need of positive information regarding the value of
various painting materials, and the advisability of having the questions
at issue determined in a practical manner.
The desire that such work should be instituted, resulted in the creation
of a Scientific Section, the scope of which was to make investigations
to determine the relative merits of different types of paint, and to
enlighten the industry on various technical problems. Paint exposure
tests of an extensive nature were started in various sections of the
country where climatic conditions vary. This field work was supplemented
in the laboratory by a series of important researches into the
properties of pigments, oils, and other raw products entering into the
manufacture of protective coatings. The results of the work were
published in bulletin form and given wide distribution. The demand for
these bulletins early exhausted the original impress, and a general
summary therefore forms a part of this volume.
The purpose of the book is primarily to serve as a reference work for
grinders, painters, engineers, and students; matter of an important
nature to each being presented. Without repetition of the matter found
in other books, two chapters on raw products have been included, and
they present in condensed form a summary of information that will prove
of aid to one who desires to become conversant with painting materials
with a view to continuing tests such as are outlined herein. In other
chapters there has been compiled considerable matter from lectures and
technical articles presented by the writer before various colleges,
engineering societies, and painters' associations.
The writer wishes to gratefully acknowledge the untiring efforts of the
members of the Educational Bureau of the Paint Manufacturers'
Association, whose early endeavors made possible many of the tests
described in this volume. Kind acknowledgment is also made to members of
the International Association of Master House Painters and Decorators of
the United States and Canada, who stood always ready to aid in
investigations which promised to bring new light into their art and
craft.
HENRY A. GARDNER.
WASHINGTON, October, 1911.
CONTENTS
CHAPTER PAGE
I PAINT OILS AND THINNERS 1
II A STUDY OF DRIERS AND THEIR EFFECT 21
III PAINT PIGMENTS AND THEIR PROPERTIES 42
IV PHYSICAL LABORATORY PAINT TESTS 70
V THE THEORY AND PRACTICE OF SCIENTIFIC PAINT MAKING 93
VI THE SCOPE OF PRACTICAL PAINT TESTS 105
VII CONDITIONS NOTED AT INSPECTION OF TESTS 114
VIII RESULTS OF ATLANTIC CITY TESTS 124
IX RESULTS OF PITTSBURG TESTS 135
X A LABORATORY STUDY OF TEST PANELS 149
XI ADDITIONAL TESTS AT ATLANTIC CITY AND PITTSBURG 174
XII NORTH DAKOTA PAINT TESTS 182
XIII TENNESSEE PAINT TESTS 201
XIV WASHINGTON PAINT TESTS 207
XV CEMENT AND CONCRETE PAINT TESTS 214
XVI STRUCTURAL STEEL PAINT TESTS 220
XVII THE SANITARY VALUE OF WALL PAINTS 252
PAINT TECHNOLOGY
CHAPTER I
PAINT OILS AND THINNERS
=Constants and Characteristics of Oils and Their Effect upon Drying.= An
attempt has been made to give in this chapter a brief summary of the
most important characteristics of those oils finding application in the
paint and varnish industry. For methods of oil analysis, the reader is
referred to standard works on this subject; the analytical constants
herein being given only for comparative purposes.
It is well known that one of the most desirable features of a paint oil
is the ability to set up in a short period to a hard surface that will
not take dust. This drying property is dependent upon the chemical
nature of the oil. If it is an unsaturated compound, like linseed oil,
rapid absorption of oxygen will cause the film to dry rapidly and become
hard. If the oil be of a fully satisfied nature, like mineral oil,
oxygen cannot be taken up to any great extent and drying will not take
place. The various animal and vegetable oils differ in their power of
oxygen absorption to a lesser or greater extent. This difference is
referred to by the chemist in terms of the iodine value. The iodine
value of linseed oil is approximately 190, meaning that one gram of the
oil will take up 190 centigrams of iodine. Oils with high iodine values
have good drying powers, while those with low iodine values are, as a
rule, very slow drying in nature.
For a description of the working and drying properties of various oils
used in paints, see Chapter XIV. The oxygen absorption of various oils
and mixtures is shown in Chapter II.
=Linseed Oil.= The seed of the flax plant which is extensively grown in
North Dakota, Argentine Republic and Russia, contains approximately 36%
of oil which may be obtained by grinding, heating, and expression. Ripe
native seed generally produces a pale oil of little odor; the oil from
Argentine seed often having a greenish tint and an odor resembling
sorghum. While filtering, pressing and ageing will remove considerable
of the ("foots") mucilaginous matter, phosphates, silica, etc., from the
oil, the better grades which are intended for varnish making are often
refined with sulphuric acid. A light colored oil which may be heated
without "breaking" results from this treatment, but such oils are apt to
contain considerable free fatty acid, unless they are washed with alkali
subsequent to the sulphuric acid treatment. On account of its rapid
drying properties and general adaptability for all classes of paints and
varnishes, linseed oil has never been supplanted by any other oil.
Chemically it consists of the glycerides of linoleic, oleic, and
isolinoleic acid, its constitution being responsible for its very high
iodine value.
[Illustration: Field of Flax in bloom in North Dakota]
Boiled linseed oil, a heavier and darker product, is made by heating the
raw oil in open kettles to high temperatures, generally with the
addition of metallic driers such as litharge, and black manganese. The
resinates of lead and manganese are often added to oil heated at a lower
temperature, to obtain a boiled oil of lighter color.
[Illustration: New type of Flax Harvester which pulls plant up by the
roots, thus preventing infection of soil]
[Illustration: Modern Concrete Elevators for storing Flaxseed]
[Illustration: View of Linseed Oil Factory showing hydraulic press,
tanks, etc.]
[Illustration: _Photographs courtesy of Spencer Kellogg Sons_
Flaxseed Crushers]
[Illustration: Filter Presses for removing extraneous matter from
linseed oil]
[Illustration: Linseed Cake from Oil Press]
[Illustration: Glycine Hispida
Mammoth soya bean plants]
[Illustration: _Photographs courtesy of David Fairchild, Plant Explorer,
U. S. Dept. of Agriculture_
Glycine Hispida
Soya bean plants under cultivation at Arlington, Va.]
By blowing air through linseed oil that has been heated to approximately
200 degrees Fahrenheit, either with or without drier, heavy bodied oils
are obtained, which find special application in varnishes and technical
paints. As the viscosity of these oils increase, the iodine values
decrease, and a slight rise in saponification value and specific gravity
is observed. The following analyses of various types of linseed oil were
recently made by the writer:
===========+========+========+=========+========+=========+=========
|Pure Raw| Boiled | Boiled | Blown | Litho. | Old
|Linseed | L. O. | L. O. | L. O. | L. O. |Treated
| Oil | (Lino- | (Resin- | | | Oil
| | leate) | ate) | | |
-----------+--------+--------+---------+--------+---------+---------
Color | Amber | Dark | Reddish | Pale | Dark | Amber
| Clear | Brown | Brown | | Brown | Clear
| | | | | |
Sp. Gr. at | .933 | .941 | .930 | .968 | .970 | .943
15 deg. C. | | | | | |
|Average | | | | |
Iodine No. | 180 | 172 | 176 | 133 | 102 | 172
| | | | | |
Saponifi- | 191 | 187 | 186 | 189 | 199 | 197
cation No. | | | | | |
| | | | | |
Free Fatty | 3.2 | 2.7 | 2.2 | 2.8 | 2.7 | 6.9
Acid | | | | | |
| | | | | |
Unsaponi- | 1.4 | -- | -- | -- | -- | 1.8
fiable | | | | | |
| | | | | |
Maumene | 111 | -- | -- | -- | -- | 96
| | | | | |
Moisture | .2% | -- | -- | -- | -- | none
===========+========+========+=========+========+=========+=========
[Illustration: Glycine Hispida
Mammoth soya bean plant]
[Illustration: Glycine Hispida
Soya bean plant, showing nitrogen gathering tubercles on roots]
=Soya Bean Oil.= The soya plant which is extensively cultivated in Asia
produces a seed bearing up to 22% and over of a golden colored oil
having a peculiar leguminous odor. The oil, which probably consists of
the glycerides of oleic, linoleic, and palmitic acids, is secured by
crushing, steaming and pressing the seed. There are several varieties of
the plant, and they are said to be the best annual legume for forage,
the straw and fruit being rich in nitrogen and very fattening as a
cattle food. Soya may be grown in nearly any country and is a great
carrier of nitrogen to land deficient in this element. Although the oil
has been used abroad for many years for soap-making purposes, its use as
a drying oil is comparatively recent; being introduced into the paint
industry of the United States during the year 1909, when linseed oil
started on its phenomenal rise in price.
The oil has given fair service in some paints when mixed with upwards of
75% of pure linseed oil. It is of a semi-drying nature, but may be made
to dry rapidly when mixed with manganese and lead linoleate driers. By
compounding it under heat with tung oil and rosin, a substitute for
linseed oil is produced, which some claim to be quite valuable.
Table I gives the constants of several samples of soya oil
examined by the writer. Table II shows the iodine value of
mixtures of soya and linseed oils. Table III shows the results of
drying experiments on soya oils containing different percentages
of lead and manganese driers.
TABLE I
CHEMICAL CHARACTERISTICS OF SOYA BEAN OIL
=======+==========+===========+============+==========+===========
Sample | Specific | Acid No. | Saponifi- | Iodine |Per cent.
No. | gravity | | cation | No. | of foots
| | | No. | |
-------+----------+-----------+------------+----------+-----------
1 | 0.9233 | 1.87 | 188.4 | 127.8 | 3.81
2 | 0.9240 | 1.92 | 188.3 | 127.2 | --
3 | 0.9231 | 1.90 | 187.8 | 131.7 | --
4 | 0.9233 | 1.91 | 188.4 | 129.8 | --
5 | -- | -- | -- | 130.0 | --
6 | -- | -- | -- | 132.6 | --
7 | -- | -- | -- | 136.0 | --
Average| 0.9234 | 1.90 | 188.2 | 130.7 | --
=======+==========+===========+============+==========+===========
TABLE II
IODINE VALUES OF LINSEED OIL AND MIXED OILS
==============+============+============+============+============
| | Soya | Soya | Soya
Sample No. | Straight |25 per cent.|50 per cent.|75 per cent.
| linseed | Linseed | Linseed | Linseed
| |75 per cent.|50 per cent.|25 per cent.
--------------+------------+------------+------------+------------
1 | 190.3 | 175.2 | 160.7 | 140.4
2 | 189.5 | 175.9 | 161.7 | 140.8
3 | 188.0 | 175.4 | 160.3 | 139.0
--------------+------------+------------+------------+------------
Average | 189.3 | 175.5 | 160.9 | 140.4
==============+============+============+============+============
TABLE III
SOYA BEAN OIL AND LEAD DRIER
=========+==========+====+====+====+====+====+====+====+====
Per cent.| | | | | | | | |
PbO | |0.05|0.10|0.30|0.50|0.70|1.00|1.30|1.60
---------+----------+----+----+----+----+----+----+----+----
| { 1 day | -- |0.07|0.63|1.34|1.05|1.53|0.93|1.35
| { 3 days| -- |0.07|3.52|4.31|2.75|4.86|4.82|4.12
Per ct. | { 5 days| -- |0.09|5.04|6.06|6.09|6.75|6.66|5.52
gain | { 12 days| -- | -- |6.88|7.54|7.43|7.76|7.32|6.47
| { 15 days| -- | -- |8.84|8.93|8.59|8.81|8.44|7.46
| { 20 days|0.05|0.20|9.02|9.08|8.90|9.03|8.65|7.83
---------+----------+----+----+----+----+----+----+----+----
SOYA BEAN OIL AND MANGANESE DRIER
-----------------+----------+----+----+----+----+----
Per cent. MnO_{2}| |0.01|0.05|0.15|0.26|0.30
-----------------+----------+----+----+----+----+----
| { 1 day | -- | -- |0.02|0.02|0.01
Per ct. gain | { 10 days| -- |5.06|6.48|6.10|5.97
| { 20 days|0.05|9.07|8.80|6.78|6.51
-----------------+----------+----+----+----+----+----
SOYA BEAN OIL, MANGANESE AND LEAD DRIER
-------------+----------+----+----+----
Per cent. PbO| |0.20|0.30|0.50
-------------+----------+----+----+----
MnO_{2} | |0.05|0.15|0.25
-------------+----------+----+----+----
| { 1 day |3.04|3.77|3.74
Per ct. gain | { 8 days|5.96|6.43|6.47
| { 12 days|6.33|6.78|6.67
=============+==========+====+====+====
=Tung Oil.= There are grown in China and Japan many varieties of the
"aleurites cordata," popularly known as the tung tree. This tree bears
great quantities of large sized nuts containing as high as 40% of an oil
which yields itself in a viscous yellow form upon heating and crushing
of the fruit. The raw oil, which chemically consists of the glycerides
of oleic, oleo-margaric, and probably isomeric acids, is distinguished
by its rapid drying properties. When spread in a thin layer it produces
a hard film with an opaque frosted surface, often showing a tendency to
wrinkle. Treated tung oil will dry to a clear, water-shedding, elastic
film. This oil is made by heating the raw tung oil at a comparatively
low temperature with other oils and a metallic drier such as litharge.
[Illustration: _Photographs courtesy of David Fairchild_
Aleurites Cordata (Chinese Wood Oil)
Barrel Factory at Cooperage Shop]
[Illustration: _Photographs courtesy of David Fairchild_
Aleurites Fordii (Chinese Wood Oil)
Fruit from trees at the end of fourth year]
The affinity of tung oil for rosin has resulted in the production of a
series of moderate-priced varnishes most suitable for use in floor and
deck paints or wherever great hardness is required. These varnishes are
also finding application in the manufacture of concrete, steel, and flat
wall paints; being especially suitable for the above purposes when
compounded with kauri gum japan.
[Illustration: Aleurites Fordii
Flowering specimen of the Chinese Wood Oil tree, thirty feet high and
three feet in diameter, on banks of Yangtse River, Western Szechuan,
China. Opium Poppy in the foreground]
[Illustration: Aleurites Cordata
Wood Oil tree at Riverside, California, planted in 1907. Photograph
taken in 1910, when tree had borne fifty fruits]
During the boiling of raw tung oil the temperature must not exceed much
over 400 degrees Fahrenheit. Otherwise a peculiar "hamming" will take
place, the whole mass becoming solid and of no further value as a
varnish or paint vehicle. Some peculiar internal disturbance or
rearrangement of the molecules is evidently effected by heat, and
although the reaction is not clearly understood, it has been ascribed to
auto-polymerization. Scott has stated that the phenomenon of
gelatinization is due to the exposure of the surface of the oil to the
air, and that boiling in vacuo obviates such results. The lusterless
surface produced when tung oil varnishes are dried in vitiated air would
tend to confirm the conclusion that the oil is very subject to
atmospheric influences.
Lumbang Oil, which is obtained from a tropical species of Tung, is very
similar in appearance and properties to Linseed Oil.
CONSTANTS OF TUNG OILS
=====+=========+============+==============+==========
| Sp. Gr. | Iodine No. |Saponification| Acid No.
| | | No. |
-----+---------+------------+--------------+----------
No. 1| .944 | 166 | 188 | 3.6
No. 2| .940 | 164 | 184 | 1.8
=====+=========+============+==============+==========
[Illustration: _Photographs courtesy Alpin I. Dunn_
Menhaden Net drying in the Sun]
[Illustration: Transporting Menhaden from net to deck of boat, in
swinging basket]
[Illustration: A big catch of Menhaden made off Narragansett Bay]
=Menhaden Oil.= Of all the marine-animal oils, such as seal, herring,
sardine, whale, and menhaden, the latter is the most valuable. It is
produced by steam digestion and pressure of the menhaden or "piogey"
fish, which are caught in great quantities off the Atlantic Coast.
Prompt cooking and treatment of the fish results in a light-colored oil
having very little odor, the residue left in the presses being of great
value as a fertilizer. Although several grades of oil termed crude,
brown, light, etc., are produced, the most satisfactory for use in paint
is that grade termed "light winter pressed." This oil is of a pale straw
color and has a high iodine number which is responsible for its rapid
drying value. It contains less of the stearates that precipitate from
crude oil, but sufficient to render its film water-shedding and elastic.
The presence of too great a quantity of stearates is apt to result in a
very soft film, and the use of hard driers, such as the metallic
tungates, is therefore advisable with menhaden oil. When mixed with
linseed oil paints the odor of menhaden oil is sometimes noticeable, but
it disappears entirely after such paints are applied. Its use with
linseed oil in technical paints exposed to the salty air of the Coast
has given good results, often preventing "checking" and "chalking."
The following constants were determined on samples of menhaden oil
received in the writer's laboratory:
========+==========+==========+==============+==========
| Sp. Gr. | Iodine |Saponification| Acid
| | Value | Number | Number
--------+----------+----------+--------------+----------
Light | .927 | 175.8 | 187.9 | 7.55
Medium | .925 | 178.7 | 187.6 | 6.19
Dark | .927 | 178.0 | 187.3 | 7.19
========+==========+==========+==============+==========
=Whale Oil.= While ordinary whale oil is too dark and odorous to ever
come into extensive use as a paint oil, it is probable that the refined
oil will be utilized in the manufacture of certain technical paints.
Whale oil is boiled from chopped whale blubber, the first trying being
the lightest in color, while the later tryings, as well as the product
made from bones, are of darker color and of very bad odor. Oil of
mirbane is often used to mask this odor. The oil contains large
quantities of stearin and palmitin, as well as wax-like constituents
which are apt to be thrown out of solution in very cold weather, or when
the oil is mixed with other oils. The refined oil, when ground with lead
and zinc pigments and mixed with equal parts of linseed oil and treated
tung oil, dries to an elastic and soft film. Experiments are being made
to utilize whale oil in the linoleum industry.
The analyses of samples of whale oil tested by the writer are as
follows:
=============+=========+========+==============+============
| Sp. Gr. | Iodine |Saponification| Free Fatty
| | Value | Number | Acid
-------------+---------+--------+--------------+------------
Light Refined| .924 | 148 | 190.2 | 1.2
Dark Yellow | .920 | 142 | 187 | 7.0
Dark Brown | .910 | 140 | 184 | 18.0
=============+=========+========+==============+============
=Sunflower Oil.= Sunflower oil is produced largely in Russia and
Hungary, finding favor in those countries as an edible oil. The ripe
seeds of the sunflower plant contain over 30% of oil which is very pale
in color and of a pleasant smell. It has been found that sunflowers may
be grown to advantage in dry parts of the United States, and if suitable
yields are obtained from a few experimental acres now being cultivated,
the industry may receive encouragement in this country. The oil should
be well suited for varnish making, and although the iodine number is not
very high, it dries quite rapidly.
[Illustration: Russian Sunflower Seeds]
CONSTANTS OF SUNFLOWER OIL
========+============+================+======
Sp. Gr. | Iodine No. | Saponification | Acid
| | No. | No.
--------+------------+----------------+------
.929 | 128 | 188 | 4
========+============+================+======
=Cottonseed Oil.= This oil is expressed from the seed of the cotton
plant, varying in color according to the time of its pressing and degree
of refinement. Being edible as well as highly suited for soap making,
very little of it comes into the market as a paint oil. It contains
large quantities of stearin and has a low iodine value, making it a slow
drying oil. Some samples are extremely light in color and contain less
mucilaginous matter and foots than is present in ordinary varieties.
CONSTANTS OF COTTONSEED OIL
========+============+================+======
Sp. Gr. | Iodine No. | Saponification | Acid
| | No. | No.
--------+------------+----------------+------
.922 | 106 | 190 | 2.4
========+============+================+======
=Corn Oil.= As a by-product in the manufacture of starch and alcoholic
liquids, this material comes into the market having a golden yellow
color, and an odor resembling fermented grain. It has a lower drying
value than cottonseed oil, and its use in the paint industry will
probably be limited to color grinding, where an oil with a semi-drying
value is often desired. Like cottonseed oil, it belongs more properly to
the soap oil class. It contains glycerides of linoleic and especially
palmitic acid.
ANALYSIS OF CORN OIL
========+============+================+=====
Sp. Gr. | Iodine No. | Saponification | Acid
| | No. | No.
--------+------------+----------------+-----
.925 | 118 | 191 | 9.5
========+============+================+=====
=Rosin Oil.= By the dry distillation of rosin, there is yielded a series
of heavy dark oils consisting principally of hydrocarbons, resinous
bodies, and free acid. These oils vary in their saponification number
from 10 to 60, while their unsaponifiable value averages about 80. Of
the grades termed first, second, third, and fourth run, the latter two
are superior for use in paints, as a rule containing less free acid than
the preliminary runs. Treatment with steam and alkali serve to
neutralize the acid nature of the oils and to remove impurities. Refined
oils are lighter in color and are often blown and bodied to fairly rapid
drying products, especially when treated with manganese driers. Rosin
oils are seldom used with lead pigments, on account of the presence of
sulphur in the oils, which would result in darkening. Rosin oil paints
work very smoothly, even when they are curdled, producing glossy
surfaces. The rapid checking of rosin oil paints on wooden surfaces bars
the use of this oil for such purposes.
ANALYSES OF ROSIN OILS
==+=========+============+================+======
| Sp. Gr. | Iodine | Saponification | Acid
| | Value | No. | No.
--+---------+------------+----------------+------
A | .966 | 41 | 27 | 16.7
B | .99 | 48 | 38 | 10.0
==+=========+============+================+======
=Hydrocarbon Oils.= Several grades of neutral or mineral oils, varying
somewhat in gravity, color, and quality, are produced as the last
distillate in the refining of petroleum. These oils when mixed with
drying oils and strong driers find application in the manufacture of
some freight-car, barn, and other paints which sell at a low price. A
small percentage of mineral oil is said to be valuable in structural
steel paints, acting as a preventative of hard drying and thus keeping
the film soft and elastic. Streaking and sweating is apt to ensue if any
great quantity is used. Mineral oils have a characteristic bloom,
showing a greenish fluorescence when examined by transmitted light. This
bloom is due to the presence of some strongly fluorescent material which
is shown up with intensity when mineral oils are exposed to ultraviolet
rays such as emanate from an enclosed arc light. Outerbridge[1] first
proposed this test for mineral oils, and he has worked out a
"fluorescent scale," by which very small percentages of hydrocarbon oils
may be detected in other oils. Several types of so-called debloomed oil
have been placed upon the market, and although such oils appear under
ordinary light conditions to be free from bloom, they fluoresce quite
strongly when given the Outerbridge test.
[1] Alexander E. Outerbridge, Jr.: "A Novel Method of Detecting
Mineral Oil and Resin Oil in Other Oils." Proc. 14th Annual Meet.,
Amer. Soc. for Testing Mater., Atlantic City, N.J., June 28, 1911.
[Illustration: View of Stills Where Petroleum Paint Thinners are
Manufactured (Waverly)]
ANALYSIS OF DEBLOOMED MINERAL PAINT OIL[2]
========+============+================+=====
Sp. Gr. | Iodine No. | Saponification | Acid
| | No. | No.
--------+------------+----------------+-----
.92 | 12 | 4 | 0
========+============+================+=====
[2] Oil of mirbane present, probably as a deblooming agent, or to mask
the odor.
=Pine Oil.= This oil is produced by the redistillation of the heavy,
high boiling point fractions resulting from the steam distillation of
wood turpentine. It is a heavy straw-colored oil, and should be of some
use in the paint and varnish industry, where a high boiling point
solvent with an oxidizing principle is desired. It will probably find
application in the manufacture of Baking Japans, Asphalt Paints and
Enamels. Its oxidizing and solvent values are very high. It has a
distinctive sweet pine smell, which makes it popular in the manufacture
of turpentine substitutes from petroleum spirits.
The writer has examined samples of this material, and the following
appear to be of the best grade:
CONSTANTS OF PINE OILS
==========================+======================+====================
| No. 1 | No. 2
--------------------------+----------------------+--------------------
Color |Straw Color |Light Yellow
Specific Gravity at 15 deg. C.|.934 |.936
Boiling Point |192 deg. C. |202 deg. C.
Distillation |95% distils between |95% distils between
| 192-270 deg. C. | 202-280 deg. C.
Residue on Evaporation |14.34% |14.60%
Polymerization Test |3-2/3% unpolymerized |2-1/2% unpolymerized
| at end of 1/2 hour | at end of 1/2 hour
Flash-Point |72 deg. C. |76 deg. C.
Spot Test |Leaves no grease spot |Same as Pine Oil No.
|but only evaporates |1.
|completely in 24 hours|
==========================+======================+====================
=Turpentine.= By direct fire or steam distillation of the sap drippings
collected in pockets cut into pine trees, there is obtained the
turpentine of commerce. It consists largely of pinene and isomeric
terpenes, and has the property of attracting oxygen, with the formation
of peroxides which stimulate the drying of oils. It is a high-grade
solvent for various gums, and is therefore used in the manufacture of
many lacquers as well as for thinning down oil-gum varnishes.
REQUISITE CONSTANTS OF PURE GUM TURPENTINE
Color Water White
Specific Gravity at 15 deg. C. .862-.875
Boiling Point About 156 deg. C.
Distillation 95% should distil between 153 and 165 deg. C.
Residue on Evaporation Not over 2%
Polymerization Not over 5% should remain unpolymerized
at end of half hour
Flash-Point Over 40.5 deg. C.
Spot Test No grease spot should remain when dropped
on paper and allowed to evaporate
Water None
=Wood Turpentine.= High-grade wood turpentine is now produced by the
steam distillation of finely cut fat pine wood. The lower-grade
qualities are often produced from the destructive distillation of
sawdust, stumpage, etc., and these products, on account of their content
of formaldehyde, are objectionable in odor. In the steam distillation
process, however, a high quality product is obtained by cutting out the
heavy fractions and redistilling the lower and purer fractions. It has a
high oxidizing value, causing the rapid drying of paints and varnishes
to which it has been added. Its solvent value is often greater than that
of gum turpentine. When properly refined it has a sweet smell and is to
be highly recommended.
Analyses of samples of pure wood turpentine which have come to the
writer for examination follow:
======================+==========================+====================
| No. 1 | No. 2
----------------------+--------------------------+--------------------
Sp. Gr. at 15 deg. C. |.862 |.862
Boiling Point |158 deg. C. |162 deg. C.
Distillation: 95% | |
distils between |158 and 185 deg. C. |162 and 177 deg. C.
Residue on Evaporation|1.03% |3.06%
Polymerization Test |4.1% remains unpolymerized|0.1 cc. out of 6 cc.
|at end of 1/2 | unpolymerized =
|hour | 1.66%
Spot Test |No grease spot on |No grease spot on
| evaporation | evaporation
Odor |Excellent |Not objectionable
Color |Water White |Water White
Flash Point | |47.6 deg. C.
======================+==========================+====================
=Petroleum Spirits.= There are produced from Texas crude oil which has
an asphaltum base, and Pennsylvania crude oil which has a paraffin base,
high boiling-point petroleum spirits which have come into wide use as
paint and varnish thinners. When such materials have the proper
evaporating value, high flash-point and freedom from sulphur, they are
to be highly recommended as paint thinners. The following shows the
analyses of a few of these materials examined in the writer's
laboratory:
PETROLEUM SPIRITS
=======================+=============+============+==============
| Texas Base | California | Penna. Base
| | Base |
-----------------------+-------------+------------+--------------
Color | Water White | White | Water White
Specific Gravity | .811 | .79 | .81
Boiling Point | 156 deg. C. | 138 deg. C.| 146 deg. C.
Flash-Point | 44 deg. C. | 40.5 deg. C.| 43 deg. C.
Residue on Evaporation | .2 | .15 | .12
=======================+=============+============+==============
=Benzol.= "Solvent naphtha" or 160-degree benzol is a product obtained
from the distillation of coal tar, differing from benzine, a product
obtained from the distillation of petroleum. It is a valuable thinner to
use in the reduction of paints for the priming of resinous lumber and
refractory woods such as cypress and yellow pitch pine. The penetrating
and solvent values of benzol are high, and it often furnishes a unison
between paint and wood, that is a prime foundation to subsequent
coatings, preventing the usual scaling and sap exudations which often
appear on a painted surface. Because of the great solvent action of
benzol, it should never be used in second and third coatings. The writer
has successfully painted inferior grades of cypress with a paint
containing benzol in the priming coat.
=Benzine.= Benzine is seldom used in paints on account of its rapid
evaporation, which is apt to cause pinholing of films and other surface
defects. In paints of the dipping type where rapid evaporation is
essential, benzine finds its widest application.