TENNESSEE PAINT TESTS
=Location and Object of Tests.= On September 15, 1910, the erection of a
wooden test fence was completed on the State Fair Grounds at Nashville,
Tenn. Upon this fence were exposed forty-two samples of white paint, the
object of the test being to determine whether the combination type of
formula is superior to the single pigment type in the southern plateau,
of which Nashville is the centre.
=Construction of Tests.= The construction and outline of these tests
differ somewhat from those conducted at Atlantic City and elsewhere by
the Scientific Section. The fence frame is 150 feet long, being made of
6-inch bevelled girders supported three feet from the ground by 4-inch
posts set six feet apart. Upon this girder were placed a series of
forty-two test panels supported at top and bottom with weather strips
and braces. The test panels used were 40 inches high, 30 inches wide,
and one inch thick, being made of the highest grade white pine, tongued
and grooved together, and protected on the edges by weather strips
projecting from the surface of the panels. Each panel was painted on
both sides with the same paint, thus giving an eastern and western
exposure, the fence running north and south. The formulas used in the
test vary in their percentage composition, being made up in some cases
of single pigments, and again with combinations of the opaque white
pigments, with and without certain percentages of the crystalline or
inert pigments. The paints were applied under the supervision of
prominent master painters and a committee representing the Scientific
Section and other technical organizations.
Other field tests have shown that the sap and knots in hard-grained
woods, such as yellow pine, cypress, etc., have been the cause of the
failure of even the best paints, and that all tests should be conducted
upon soft woods, such as white pine and poplar, if definite results are
to be obtained. Paints tinted with ochre, chrome yellow, lampblack,
iron oxide, etc., have shown on the other field tests which have been
conducted at Atlantic City, Pittsburg, and Fargo the value of these
pigments in giving to the paints increased wearing properties. On the
Southern Test Fence, therefore, all the formulas were ground in white
only and placed upon white pine so as to make the test primarily one to
determine the value of the various white pigments upon good wood.
[Illustration: Tennessee Test Fences]
=Oil and Thinner Tests.= Upon one series of panels on the fence was
placed one of the formulas which had given universal satisfaction on the
various test fences in the past, and this formula was made up with
various oils other than linseed oil, in order to determine the value of
these oils as painting materials. For instance, the vehicle part of the
one formula referred to is made up of 50% linseed oil and 50% soya bean
oil, and again 50% linseed oil and 50% rosin oil, etc., an effort being
made to test out a few of the available semi-drying oils.
The same formula referred to was ground in pure linseed oil and
subjected to a series of tests where it has been thinned for application
as priming and second coats with a series of wood turpentines obtained
from the United States Forest Products Laboratory at Madison, Wis. These
turpentines were made from southern pine stumps and sawdust, and they
vary greatly in their properties. Some were objectionable in odor, while
others were of excellent quality, having an odor almost equal to that of
pure gum spirits.
[Illustration: Views of Fence]
One product under test on the Southern Test Fence is pine oil, a high
boiling point product obtained from the manufacture of wood turpentine
from sawdust. This oil has a boiling point of over 210 degrees
Centigrade as against the 150 degrees of ordinary gum spirits. It is
almost water white and has the same penetrating qualities as the pure
gum spirits; when mixed with 50% linseed oil forming a paint oil of
extremely light color, that produces a semi-flat paint of great
whiteness.
=Reductions and Application.= Formulas No. 1 to No. 37 were all ground
in pure refined linseed oil. They were made in the form of semi-paste
and then thinned down with sufficient refined linseed oil so that each
would have a relative viscosity. To each formula was then added a
sufficient amount of pure lead and manganese linoleate drier to give
proper drying qualities. On thinning for the priming coat, one pint of
turpentine was added to each gallon of paint. For the second coat,
one-half pint turpentine and one-half pint refined linseed oil were
added to each gallon. For the third coat work, reduction was made with
one pint of refined linseed oil.
In the case of formulas 31 to 37, reductions were the same, except that
a series of specially prepared wood turpentines were used in place of
the pure gum spirits used in formulas 1 to 31.
Formulas 38 to 41, as will be shown, were ground in equal parts of the
oils tested. These formulas, however, were all thinned for application
with pure gum spirits of turpentine, and the respective vehicle in which
they were ground.
No inspection of the Tennessee Test Fence has yet been made. The
formulas tested are as follows:
FORMULAS FOR SOUTHERN TEST FENCE
VEHICLE: _Bleached Linseed Oil with Lead and Manganese Linoleate Drier_.
Formula
No.
1 [30]Corroded white lead 100%
2 [30]Sublimed white lead 100%
3 Zinc oxide XX 100%
4 Zinc lead white 100%
5 Leaded zinc 65%, corroded white lead 35%
6 [30]Corroded white lead 100%
7 [30]Corroded white lead 100%
[30] Corroded White Lead is the Basic Carbonate of Lead. Sublimed
White Lead is the Basic Sulphate of Lead.
No. 8
Corroded white lead 85%
Zinc oxide 15%
----
100%
No. 9
Corroded white lead 65%
Zinc oxide 35%
----
100%
No. 10
Corroded white lead 50%
Zinc oxide 50%
----
100%
No. 11
Corroded white lead 40%
Zinc oxide 60%
----
100%
No. 12
Corroded white lead 30%
Zinc oxide 70%
----
100%
No. 13
Corroded white lead 45%
Zinc oxide 45%
Silica 10%
----
100%
No. 14
Corroded white lead 45%
Zinc oxide 45%
Asbestine 10%
----
100%
No. 15
Corroded white lead 45%
Zinc oxide 45%
China clay 10%
----
100%
No. 16
Corroded white lead 45%
Zinc oxide 45%
Barytes 10%
----
100%
No. 17
Corroded white lead 45%
Zinc oxide 40%
Silica 15%
----
100%
No. 18
Corroded white lead 45%
Zinc oxide 40%
Asbestine 15%
----
100%
No. 19
Corroded white lead 45%
Zinc oxide 40%
Barytes 15%
----
100%
No. 20
Sublimed white lead 45%
Zinc oxide 40%
Silica 15%
----
100%
No. 21
Sublimed white lead 45%
Zinc oxide 40%
Asbestine 15%
----
100%
No. 22
Sublimed white lead 45%
Zinc oxide 40%
Barytes 15%
----
100%
No. 23
Zinc oxide 90%
Calcium carbonate 10%
----
100%
No. 24
Sublimed white lead 40%
Zinc oxide 45%
Calcium carbonate 15%
----
100%
No. 25
Corroded white lead 35%
Zinc oxide 50%
Silica 15%
----
100%
No. 26
Corroded white lead 20%
Sublimed white lead 30%
Zinc oxide 40%
Asbestine 10%
----
100%
No. 27
Corroded white lead 20%
Sublimed white lead 20%
Zinc oxide 40%
Barytes 10%
Asbestine 10%
----
100%
No. 28
Corroded white lead 20%
Sublimed white lead 20%
Zinc oxide 40%
Calcium carbonate 10%
Silica 10%
----
100%
No. 29
Sublimed white lead 20%
Corroded white lead 20%
Zinc oxide 30%
Barytes 10%
Asbestine 10%
Calcium carbonate 10%
----
100%
No. 30
Corroded white lead 33%
Zinc oxide 33%
Barytes 33%
----
99%
No. 31
Corroded white lead 45%
Zinc oxide 45%
Asbestine 5%
Calcium carbonate 5%
----
100%
Formula No.
32. Same as No. 31 but thinned with wood turpentine No. 1.
33. Same as No. 31 but thinned with wood turpentine No. 2.
34. Same as No. 31 but thinned with wood turpentine No. 3.
35. Same as No. 31 but thinned with wood turpentine No. 4.
36. Same as No. 31 but thinned with wood turpentine No. 5.
37. Same as No. 31 but thinned with high-boiling-point petroleum spirits
(turpentine substitute).
38. Same as No. 31 but ground in 50% raw linseed oil, 50% soya bean oil.
39. Same as No. 31 but ground in 50% raw linseed oil, 50% corn oil.
40. Same as No. 31 but ground in 50% raw linseed oil, 50% cotton seed
oil.
41. Same as No. 31 but ground in 50% raw linseed oil, 50% rosin oil.
42. Same as No. 31 but ground in 50% raw linseed oil, 50% pine oil.