CHAPTER VIII_Paint Technology and Tests

RESULTS OF ATLANTIC CITY TESTS

=Results on Various Woods.= On the Atlantic City Fence all the tests

made on yellow pine and cypress were found to be in an unsatisfactory

condition for a report, for in every case the sap and small knots

contained in such wood had a very bad effect upon the paint, causing

peeling and scaling. The white pine panels were in very much better

condition, and it was therefore decided to make the inspection entirely

from the white pine panels and in the future to remove the yellow pine

and the cypress panels from the fence and from the test. The Committee

advised that all future tests be made on white pine, as it is obviously

unfair to use anything but the highest grade wood for a paint test in

which the desire is to determine the comparative wearing value of

pigments.

NOTE.--Recent tests have shown that Cypress may be successfully

painted when the priming coat of paint is thinned with Benzol

(Solvent Naphtha).

[Illustration: Panels on Atlantic City Fence Two Lower Sets of Panels

are painted with Lithopone Paints. Rapid Failure shown]

[Illustration: Panels on Atlantic City Fence]

[Illustration: Panels on Atlantic City Fence

Two Lower Sets of Panels are Painted with Combination Pigment Paints.

Excellent Results shown]

=Paints Containing Lithopone.= One of the most striking exhibitions of

paint disintegration in the whole test was the failure of nearly all the

lithopone formulas tested. At the time these formulas were suggested for

the test, various European technical journals had advocated the use of

lithopone in large percentage for paints to be used on exterior

surfaces. Good results had been obtained in the northwestern section of

Europe, with this pigment in certain mixtures, and the object of these

lithopone tests at Atlantic City and Pittsburg was to determine whether

satisfactory paints could be made of this pigment for exposure in this

country. Failure of the tests, however, in nearly every case except

where zinc oxide and whiting were mixed with the lithopone, indicated

that pigments such as zinc and whiting are necessary in order to prevent

the decomposition of lithopone pigment paints. The decay of lithopone

paints after they are applied seems to start with rapid oxidation of the

linseed oil, and this oxidation seems to continue in a progressive and

even accelerated way; after six months' exposure the surface of the

paint being chalked to a great extent and showing rapid decomposition of

the binder or vehicle. Inasmuch as lithopone is really an inert pigment,

this rapid decomposition of its vehicle cannot be explained in the same

way as the decomposition of the vehicle of pure white lead paints, where

the alkaline nature of the lead is probably responsible for the

formation of easily destroyed compounds. As complete failure had taken

place in nearly every case where lithopone had been used, it was decided

to condemn the lithopone panels on the fence, consisting of formulas 21

to 27, including panels 151 to 164 in white, panels 131 to 144 in

yellow, and 109 to 122 in gray. These lithopone tests were later on

replaced by new tests in 1909, which will be reported upon later in this

book.

=General Results.= From these tests, the inspectors reached the

unanimous conclusion that a paint made from any mixture of more than one

white opaque pigment, either when used alone or in combination with

small percentages of inert pigments, is far superior to any one single

pigment paint. It was found that the straight white lead paints failed

in every case, and this failure was so marked as to make it a conclusive

demonstration of the unfitness of white lead along the Atlantic coast,

when used without other pigments. Paints made with large percentages of

white lead, however, gave excellent results.

Gypsum was found unsafe to use in any large proportion in a paint,

because of its solubility and liability to percolate through the coating

of linoxyn or dried film, thus destroying the surface of the paint.

Whiting, or calcium carbonate, demonstrated that it could be used in

moderate percentage with some efficiency, but it was evident that any

great excess of this pigment must also be avoided on account of its

tendency towards rapid chalking. Magnesium silicate, aluminum silicate,

and silica are three inert pigments which proved to be of great value in

strengthening and reinforcing paints, especially when they were used in

small percentage. In the same way, black fixe and barytes, or barium

sulphate, also appeared to be useful in strengthening a paint. As these

two last named pigments are chemically the same but physically

different, the use of both in a paint formula is considered

advantageous, because of the differences in size and form of their

particles.

=Color Tests.= It was the unanimous conclusion of all the inspectors

that panels of all formulas which were tinted either gray or yellow were

showing far superior wear and less chalking and checking than those

which were painted in plain white. The reinforcing action of the tinting

materials must be credited for this lengthening of the wear of such

paints. Formulas 5, 6, 9, and 16, for instance, in the gray, were in

most excellent condition, and in these formulas were used ochre, umber,

bone-black, carbon-black, Venetian red and other inert bases. On the

yellow panels, formulas 5, 6, 9, and 16 were also in very superior

condition, and in these formulas chrome yellow and inert pigments were

also used.

Some of the color tests included the priming of boards with white lead,

zinc oxide, sublimed white lead, lithopone, and other single pigment

paints. Over these priming coats was placed a high grade brilliant

paranitraniline red. Fairly good results were obtained in every case,

but especially when lithopone or zinc oxide was used as a priming base.

These pigments seemed to have no effect upon the constitution of the

para red.

Prussian blue, a colored pigment largely used, but one liable to react

with certain paint pigments, was admixed with various paints applied to

certain panels. This color was found in some cases to have faded

materially, especially when mixed with alkaline pigments such as white

lead. Sublimed white lead and zinc oxide, which are more inert in

nature, did not have such action on Prussian blue, and the tinted bases

of these pigments stood up in a remarkable manner. The greens which were

tested were all in very good condition, with absence of fading, and

showing only slight mildew.

=Condensed Results of Inspection.= The results of inspection as obtained

by the fence committee[20] having in charge the inspection of the test,

have been condensed into table form, and are presented on pages 130-131.

[20] R. S. Perry, Director Scientific Section, Paint Manufacturers'

Association of the U. S.; George Butler, Official Painter,

representing Master House Painters' & Decorators' Association, H.

A. Gardner, Asst. Director.

=Second Annual Inspection of the Atlantic City Test Fence.= After the

original paints which had been applied to the Atlantic City Fence had

been exposed for over two years, another inspection was made by a

committee representing the Master Painters' Association of Philadelphia

and the Scientific Section of the Paint Manufacturers' Association of

the United States. A digest of the report of this committee[21] follows:

[21] George Butler, Official Painter Atlantic City Test Fence,

representing Philadelphia Master Painters' Association; Charles

Macnichol, Master Painter; Henry A. Gardner, Director Scientific

Section, Paint Manufacturers' Association of the U. S.

"The painted panels were all carefully inspected by the inspectors in

the usual manner. With the aid of high-power magnifying glasses,

checking was determined. The degree of chalking exhibited by the various

paints was ascertained by rubbing a piece of black cloth across the

surface of each paint. Close observance was made to determine scaling,

peeling, cracking, gloss, color, and the other factors to be considered

when examining a painted surface. From these observations it was

possible for the inspectors to state whether a panel exhibited general

good condition, general fair condition, or general poor condition.

CHART OF RESULTS--FIRST INSPECTION--ATLANTIC CITY TEST FENCE

==============================+=================================+

Formula | INERT PIGMENTS |

No. |---------------------------------|

|Carbonate |Calcium |

|Lead |Carbonate |

--+------+------+------+------+-----+-----+-----+----+----+-----+

| % | % | % | % | % | % | % | % | % | % |

1| 30.0 | 70.0 | | | | | | | | |

2| 50.0 | 50.0 | | | | | | | | |

3| 20.0 | 50.0 | 20.0 | |10.0 | | | | | |

4| 48.5 | 48.5 | | | 3.0 | | | | | |

5| 22.0 | 50.0 | | | 2.0 | |26.0 | | | |

6| | 64.0 | | | | | |36.0| | |

7| 37.0 | 63.0 | | | | | | | | |

8| 38.0 | 48.0 | | | | | | |14.0| |

9| | 73.0 | | | | | 2.0 | |25.0| |

10| 44.0 | 46.0 | | | 5.0 | | 5.0 | | | |

11| 50.0 | 50.0 | | | | | | | | |

12| 60.0 | 34.0 | | | 6% Inert Pigments |

13| | 27.0 | 60.0 | | 3.0 | |10.0 | | | |

14| 25.0 | 25.0 | 20.0 | | 5.0 |25.0 | | | | |

15| 20.0 | 40.0 | | 30.0 |10.0 | | | | | |

16| 33.0 | 33.0 | | | | | |34.0| | |

17| 40.0 | 40.0 | | | | | 3.0 |13.0| | 4.0 |

18| 75.0 | 25.0 | | | | | | | | |

19| | 25.0 | 75.0 | | | | | | | |

20| 67.0 | 19.5 | | |10.0 | | 3.5 | | | |

33| 15.0 | 30.0 | 25.0 | | | | | |30.0| |

34| 38.95| 33.58| 4.81| |19.48| | 3.18| | | |

35| 37.51| 25.87| 7.84| |20.36| | 8.42| | | |

36|100.0 | | | | | | | | | |

37|100.0 | | | | | | | | | |

38|100.0 | | | | | | | | | |

39| | | |100.0 | | | | | | |

40| | |100.0 | | | | | | | |

45| |100.0 | | | | | | | | |

46| | 61.0 | | | | | |39.0| | |

47| |100.0 | | | | | | | | |

==+======+======+======+======+=====+=====+=====+====+====+=====+

======================+==========+======+=========+======+

No. |No. |Power | | ness |

| | | | age | | | | | |

--+---+----+----+-----+---+------+------+---------+------+

| | | | | | | | | |

1|610| 987| 664| 754| 1|Good |Good |Excellent| 8 |

2|913|1066| 948| 976| 3|Good |Good |Good | 5 |

3|912| 914| 786| 871| 5|Good |Fair |Good | 4 |

4|759| 939|1047| 915| 7|Good |Good |Good | 5 |

5|714|1000| 709| 808| 9|Good |Weak |Good | 8-1/2|

6|928|1189| 863| 993| 11|Fairly|Weak |Good | 8 |

7|763| 972| 891| 875| 13|Good |Good |Off Color| 7 |

8|786| 910| 767| 821| 15|Good |Good |Good | 8-1/2|

9|716|1081| 812| 870| 17|Fair |Poor |Good | 9 |

10|861|1014| 862| 912| 19|Good |Fair |Good | 5 |

11|822| 959| 918| 900| 21|Good |Good |Excellent| 7-1/2|

12|862| 965| 734| 854| 23|Good |Medium|Good | 4 |

13|916|1031|1121| 1073| 25|Good |Good |Good | 4 |

14|564| 806| 785| 718| 27|Bad |Medium|Good | 5 |

15|935|1044|1359| 1113| 29|Good |Medium|Good | 8-1/2|

16|799| 903| 994| 899| 31|Fair |Fair |Good | 7-1/2|

17|806|1016| 884| 902| 33|Good |Fair |Good | 4 |

18|788|1257| 973| 1006|145|Good |Good |Excellent| 3 |

19|700|1183|1400| 1094|147|Good |Good |Excellent| 2 |

20|776|1063| 877| 905|149|Good |Good |Good | 5 |

33|512| 836| 689| 679|176| |Fair | | |

34|523| 800| 810| 711|175|Good |Medium|Good | 4 |

35|450| 893| 724| 689|180|Good |Good |Good | 4 |

36|408| 711| 861| 660|181|Bad |Good |Good | 1 |

37|524|1065| 828| 806|182|Bad |Good |Good | 1 |

38|555| 888| 794| 746|177|Bad |Good |Good | 1 |

39|550| 941| 916| 802|178|Good |Fair |Good | 6 |

40|643| 810| 998| 817|168|Good |Good |Good | 2 |

45|850| | | |170|Fair |Fair |Good | 9 |

46|783| | | |169|Fair |Good |Good | 9 |

47|730| | | |172| |Good |Good |10 |

==+===+====+====+=====+===+======+======+=========+======+

==============+===========+===========+===============================

Formula | | |

No. | | |

|Checking |Chalking |Gloss |Remarks

--+-----------+-----------+-----------+-------------------------------

| | | |

1| |Very Slight|High |Like rubbed varnish work.

2|Hard Matt |Moderate |Med. High |

3| |Medium |Slight |

4| |Very Slight|Med. High |

5| |Slight |High |Hard surface.

6|Matt | |Good |Surface rough.

7| |Slight |High |

8| |Slight |High |

9|Heavy Matt |Medium |High |Peeling started.

10| |Some | Med. High |

11|Med. Matt |Some |Med. High |Some washing and discoloration.

12|Heavy Matt |Bad |Medium |

13| |Medium |Fair |

14|Evident |Some |Medium |Dead, spongy, surface. White

| | | |incrustations.

15|Coarse Matt|Slight |High |

16|Bad |Slight |Good |White incrustations.

17| |Some |Fair |

18|Hard Matt |Moderate |Medium |

19|Hard Matt |Slight |Very Little|

20| |Very Little|Medium |

33| | |Good |Rough surface.

34|Evident |Slight |Egg Shell |

35|Matt | |Egg Shell |

36|Very |Bad |Egg Shell |Same as 177, but

|Apparent | | |checking not so bad.

37|Very |Bad |Egg Shell |Same as 177 but wood

|Apparent | | |shows more plainly.

38|Bad |Bad |Egg Shell |Cracking and perishing evident.

39| |Some |Good |

40| |Consider- |Egg Shell |

| |able | |

45|Very Evi- | |High |

|dent | | |

46|Some | |Good |

47|Apparent | |Good |Indication of scaling.

==+===========+===========+===========+===============================

"An inspection of the white lead paints on the fence indicated in every

instance a rough, chalked, and disintegrated surface that seemed to be

well worn, in some cases nearly to the wood. The strongly oxidizing air

of the seacoast is probably responsible for the early decay of this

pigment.

"It was observed that the combination type of paint showed better hiding

power than white lead, over the black crosses placed on the priming coat

of each panel, as a hiding power test.

[Illustration: Front of Fence showing Present Rearrangement of Panels]

TESTS INAUGURATED IN 1907

CHART OF RESULTS OF SECOND ANNUAL INSPECTION OF ATLANTIC CITY TEST

FENCE, MAY, 1910

=========================================================+

FORMULAS |

--+------------------------+-----------------------------+

F | | INERT PIGMENTS |

o | +-----------------------------+

r |Basic Carbonate |Calcium |

m |White Lead |Carbonate |

b | | | --+ | | | | | |Blanc|

e | | | | | | | | | | Fixe|

r | | | | | | | | | --+ |

--+------+------+------+---+-----+--+----+-----+-----+---+

| % | % | % | %| % | %| % | % | % | %|

1| 30 | 70 | -- | --| -- |--|-- |-- |-- | --|

2| 50 | 50 | -- | --| -- |--|-- |-- |-- | --|

3| 20 | 50 | 20 | --|10 |--|-- |-- |-- | --|

4| 48.5 | 48.5 | -- | --| 3.0 |--|-- |-- |-- | --|

5| 22 | 50 | -- | --| 2 |--|26 |-- |-- | --|

6| -- | 64 | -- | --| -- |--|-- |36 |-- | --|

7| 37 | 63 | -- | --| -- |--|-- |-- |-- | --|

8| 38 | 48 | -- | --| -- |--|-- |-- |14 | --|

9| -- | 73 | -- | --| 2 |--|-- |-- |25 | --|

10| 44 | 46 | -- | --| 5 |--| 5 |-- |-- | --|

11| 50 | 50 | -- | --| -- |--|-- |-- |-- | --|

12| 60 | 34 | -- | --| -- | 6% Inert Pigment | --|

13| -- | 27 | 60 | --| 3 |--|10 |-- |-- | --|

14| 25 | 25 | 20 | --| 5 |25|-- |-- |-- | --|

15| 20 | 40 | -- | 30|10 |--|-- |-- |-- | --|

16| 33 | 33 | -- | --| -- |--|-- |34 |-- | --|

17| 40 | 40 | -- | --| -- |--| 3 |13 |-- | 4|

18| 75 | 25 | -- | --| -- |--|-- |-- |-- | --|

19| -- | 25 | 75 | --| -- |--|-- |-- |-- | --|

20| 67.0 | 19.5 | -- | --|10.0 |--| 3.5|-- |-- | --|

33| 15 | 30 | 25 | --| -- |--|-- |-- |30 | --|

34| 38.95| 33.58| 4.81| --|19.48|--|-- | 1.59| 1.59| --|

35| 37.51| 25.87| 7.84| --|20.36|--|-- | 4.21| 4.21| --|

36|100 | -- | -- | --|-- |--|-- |-- |-- | --|

37|100 | -- | -- | --|-- |--|-- |-- |-- | --|

38|100 | -- | -- | --| -- |--|-- |-- |-- | --|

39| -- | -- | -- |100| -- |--|-- |-- |-- | --|

40| -- | -- |100 | --| -- |--|-- |-- |-- | --|

45| -- | 90 | -- | --|10 |--|-- |-- |-- | --|

46| -- | 61 | -- | --| -- |--|-- |39 |-- | --|

47| -- |100 | -- | --| -- |--|-- |-- |-- | --|

==+======+======+======+===+=====+==+====+=====+=====+===+

==+========================================+===

F | |

o | |

r | | P

m | | a

u | | n

l | | e

a | | l

| REPORT OF INSPECTION |

N +-----------+------------+------+--------+ N

u | | |GENE- | | u

m | | |RAL | | m

b | | |CON- | | b

e | | |DI- | | e

--+-----------+------------+------+--------+---

1|Very slight|Very slight |Good |-- | 1

2|Medium |Slight |Very |-- | 3

3|Medium |Slight |Good |-- | 5

4|Very slight|Slight |Good |-- | 7

5|Slight |Slight |Good |-- | 9

6|Very slight|Slight |Good |-- | 11

7|Medium |Slight |Good |-- | 13

8|Slight |Very slight |Good |-- | 15

9|Very bad |Deep, with |Poor |-- | 17

10|Heavy |Deep |Medium|-- | 19

11|Medium |Medium |Fair |-- | 21

12|Medium |Deep |Fair |-- | 23

13|Medium |Slight |Very |-- | 25

14|Medium |Lateral |Fair |-- | 27

15|Slight |Visible with|Poor |-- | 29

16|Slight |Slight |Good |-- | 31

17|Medium |Slight |Good |-- | 33

18|Medium |Slight |Very |-- |145

19|Consider- |Deep |Good |-- |147

20|Medium |Slight |Good |-- |149

33|Medium |Slight |Very |-- |176

34|Slight |Slight |Good |-- |175

35|Slight |Lateral |Good |-- |180

38|More than |Very deep |Poor |-- |177

|182 | | | |

39|Consider- |Very slight |Good |-- |178

40|Heavy |Slight |Good |-- |168

45|Slight |Slight |Good |-- |170

46|Slight |Medium |Fair |-- |169

47|None |Very deep |Poor |-- |172

==+===========+============+======+========+===

"There are no pigments possessing greater hiding properties when first

used than white leads, but the lack of hiding power on the white lead

panels after two years' exposure was caused by the chalking away of the

lead. The superior hiding power of the composite paints was due to the

action of the other pigments in these combination paints in preventing

the lead from chalking away.

"The Committee finds that the addition of a reasonable percentage of

zinc oxide to white lead increases its durability and retards its

chalking, renders it whiter, and forms a surface that presents a much

better repainting condition. The combinations of white lead and zinc

oxide on the Atlantic City Test Fence were in general good condition

throughout.

"Corroded white lead, sublimed white lead, zinc oxide, and zinc lead are

the standard white opaque pigments. They were all tested on the Atlantic

City Fence and it was found that to use any one alone results in

inferior protection to the wood. Barium sulphate, silica, asbestine,

china clay, and calcium carbonate are the standard crystalline pigments.

In the past, the overloading of paints with these crystalline or inert

pigments has been the cause of the prejudice that painters have had

against their use. It has been established beyond controversy, however,

that the use of these pigments, in moderate percentage, combined with

any of the standard opaque white pigments, such as white leads, zinc

oxide, etc., undoubtedly results in better service from every standpoint

and forms the most satisfactory white paint for general outside use.

Some of the most perfect painted surfaces on the fence were those made

on the above basis as reference to the charted report will show."