Paint Technology and Tests Part 17

[Ill.u.s.tration: Typical Sample of Hard Pine Trim Board Showing Knot and Sappy Grain]

[Ill.u.s.tration: Test No. 13--1906 Fence

Complete Disintegration and Failure of Cheap Paint]

"Non-absorbent woods, difficult to penetrate, such as those on the west side of the fences, would undoubtedly have given much better results had they been painted with paints properly reduced to suit the nature of the wood. This treatment seems to have been overlooked in the North Dakota tests, and the painting of the hard pine boards was done with the same consistency of mixtures and the same reductions as upon soft pine.

Scaling of course resulted. One of the chief purposes of the fences, however, was to study the different types of wood, and compliance with this desire resulted in the bad conditions herein noted. It has been shown in many other field tests that adherence of paints to hard wood surfaces can be obtained only by causing the priming coat to become amalgamated with the woody fibre, by the use of a large percentage of volatile diluent turpentine, benzole, asphaltum spirits, etc., to secure penetration. If such treatment is omitted, failure soon results, as was evidenced by the uniformly bad conditions presented by the paints on the hard pine panels.

[Ill.u.s.tration: Pine Weatherboarding Showing Knots and Grain]

[Ill.u.s.tration: Condition of Lumber Affecting Paint, West Side 1906 Fence]

[Ill.u.s.tration: Hail-stone Abrasions on House Repainting Tests]

[Ill.u.s.tration: Hail-stone Effect, West Side of 1907 Test Fence]

"During July, 1908, a violent hailstorm occurred in Fargo, and left its impression on nearly every wooden structure; in many cases deep dents being made into the wood. The west side of the test fences, which received the most injury from this storm, was covered with these dents over almost its entire surface, causing cracks in the form of concentric rings to appear on the abraded paint coatings. The bad condition of the wood, improper method of applying priming coat, combined with the hailstorm effect on the painted surfaces on the west side of the fences, were undoubtedly responsible for the universal failure of the paints thereon, and, for these reasons, the west side was eliminated from the detailed inspection, only general observations of these tests being made. These general observations, however, showed that paints Nos. 6 and 8 on the 1906 fence, and paints Nos. 8, 10, and 13 on the 1907 fence, proved the most satisfactory on the western exposure.[29]

[29] These formulas were the same as those respectively numbered on the Atlantic City and Pittsburg fences.

[Ill.u.s.tration: Peculiar Crystallization Effect on Section 41. New Special Fence Paint Applied During Cold Weather]

"Ochre was tried out as a priming coat on several formulas, but it was found to be most unsatisfactory, affecting the subsequent coats of paint and causing early failure, as evidenced by broad checking, discoloration, and general bad condition. These conditions also apply to those panels on the 1908 fence coated with sh.e.l.lac as a primer.

"The colored formulas in every case showed a great superiority over the same paints in white untinted, and demonstrated that a percentage of color has a wonderful influence on the preservation of the paint coating, reducing chalking, checking, and general disintegration. This condition is probably due to the reinforcing value of the color pigments used.

"It is safe to state that the combination formulas tinted yellow were of better appearance than the corroded white leads tinted yellow, the latter appearing quite dark in many cases.

"The wearing of the paints made solely from white lead and zinc oxide seemed to indicate that a percentage of a third pigment, of an inert nature, would have been beneficial.

"The high-type mixtures of pigments containing lead and zinc, with moderate percentages of inert pigments, on good wood, were in most excellent general condition; in fact, much superior to the single pigment paints. Their surface exhibited only minor checking and moderate chalking with good maintenance of color, and presenting surfaces well adapted to repainting.

"The sublimed white lead was in fair condition, with very little checking, and offering a fair repainting surface. The corroded white lead was somewhat whiter than the sublimed white lead, but a careful observation of the surface of the corroded lead revealed deep checking.

"It was clearly demonstrated, however, that in climates of the North Dakota type, white lead alone is not entirely satisfactory. The addition of zinc oxide to white lead forms paint that has proved much superior to the white lead alone.

"It was conclusively demonstrated that mixtures of white lead and zinc oxide, properly blended with moderate percentages of reinforcing pigments, such as asbestine, barytes, silica and calcium carbonate, are most satisfactory from every standpoint, and are superior to mixtures of prime white pigments not reinforced with inert pigments.

"The white leads painted out on the 1908 fence exhibited different degrees of checking, the mild-process lead and sublimed white lead which presented the best surfaces, being free from checking, while the old-process leads seemed to show very deep and marked checking, even after one year's wear.

[Ill.u.s.tration: Corroded White Lead

Sublimed White Lead

Condition of Two White Leads on Two Grades of Wood]

[Ill.u.s.tration: Photomicrographic Apparatus and Method of Use]

CONDENSED REPORT OF INSPECTION OF "1906" TEST FENCE

FARGO, N. D., NOV. 19-23, 1909

_No gloss shown by any of the paints. Formulas in white on white pine only included here, on east side of fence_

==+=========================================================================++ T| FORMULAS || e+--------------------------------------------+----------------------------++ s| PIGMENT | VEHICLE || t+--------------------------------------------+----------------------------++ |Corroded |Linseed Oil || N|White Lead | |Turp. and Drier || o| |Sublimed | | |j.a.pan Drier || .| |White Lead | | | |Water || | | |Zinc Oxide | | | | |Benzine || | | | |Calcium | | | | |Drier || | | | |Carbonate | | | | | |Vola-|| | | | | |Silica and | | | | | |tile || | | | | |Silicates | | | | | |Oil || | | | | | |Barium Sulphate | | | | | | || | | | | | | |Magnesium | | | | | | || | | | | | | |Silicate | | | | | | || | | | | | | | |Clay and | | | | | | || | | | | | | | |Silica | | | | | | || | | | | | | | | |Bary-| | | | | | || | | | | | | | | |tes | | | | | | || | | | | | | | | |and | | | | | | || | | | | | | | | |Sili-| | | | | | || | | | | | | | | |cate | | | | | | || --+-----+-----+----+----+---+----+---+---+-----+----+----+--+----+----+-----++ | % | % | % | % | %| % | %| %| % | % | % | %| % | % | % || 1|100 | -- | -- | -- | --| -- | --| --| -- | -- | -- |--| -- | -- | -- || 2| -- |100 | -- | -- | --| -- | --| --| -- | -- | -- |--| -- | -- | -- || 3| 50 | -- |50 | -- | --| -- | --| --| -- |90 |10 |--| -- | -- | -- || 4| -- | 60 |40 | -- | --| -- | --| --| -- |90 | -- |10| -- | -- | -- || 5| 28.7| -- |71.3| -- | --| -- | --| --| -- |93 | 7 |--| -- | -- | -- || 6| 40.2| -- |50.3| 4.1|5.4| -- | --| --| -- |90.7| 9.3|--| -- | -- | -- || 7| 21.9| 21.9|45.8|10.4| --| -- | --| --| -- |89.6| 9.7|--| 0.7| -- | -- || 8| 44.1| -- |46.0| 4.6| --| -- |5.3| --| -- |86.0|12.6|--| 1.4| -- | -- || 9| In gray only No report. || 10| 13.9| -- |34.9|26.8| --| -- | --| --| 24.4|72.2| -- |--|24.0| 3.8| -- || 11| 55.0| -- |15.2| -- | --| -- | --| --| 29.8| Test not finished || 12| -- | 5.1|25.0| -- | --| -- | --| --| 69.9| -- | -- |--| -- | -- | -- || 13| -- | -- |31.3|45.4| --|22.8| --|0.5| -- |57.2| -- |--|16.1|26.7| -- || 14| 34.8| 5.4|59.2| -- | --| -- | --| --| -- |86.0|13.7|--| 0.3| -- | -- || 15| -- | -- |64 | -- | --|36 | --| --| -- |98 | -- |--| -- | -- | 2 || ==+=====+=====+====+====+===+====+===+===+=====+====+====+==+====+====+=====++

==+============================================== | REPORT OF CONDITION +--------+-----------+-------+-------+--------- T| | | | | e| | | | | s| | | | | t| | | | | | | | | | N| | | | |CONDITION o|CHALKING|CHECKING |HIDING |COLOR |FOR RE- .| | |POWER | |PAINTING --+--------+-----------+-------+-------+--------- 1|Very bad|Extremely |Good |Good |Only fair | |deep | | | 2|Bad |Very slight|Good |Light |Fair | | | |yellow-| | | | |ish | | | | |tint | 3|Medium |Fine matt--|Good |Fair |Fair to | |deep in | | |good | |places | | | 4|Medium |Surface |Good |Good |Fair | |checking, | | | | |very slight| | | 5|Slight |Quite deep |Medium |Good |Poor.

| | | | |Coating | | | | |wrinkled | | | | |and hard 6|Medium |Slight |Good |Good |Good | |surface | | | | |checking | | | 7|Medium |Surface |Fair |Good |Slight | |checking | | |sh.e.l.ling | |with slight| | |from wood | |cracking | | | 8|Medium |Very slight| Good |Good |Good 9| | | | | 10|Slight |Very bad | Bad condition throughout.

11| | | | | 12|Medium |Medium |Defici-|Good |Sh.e.l.ling | | |ent | |from wood 13| Worst looking surface in North Dakota tests.

14|Medium |Slight |Fair |Good |Good | |surface | | | | |checking | | | | |and peeling| | | 15|Slight |Lateral |Good |Good |Hard film | |cracking | | | | |quite deep | | | ==+========+===========+=======+=======+=========

CONDENSED REPORT OF INSPECTION OF "1907" TEST FENCE

FARGO, NORTH DAKOTA, NOV. 19-23, 1909

===+========================================================================== T | FORMULAS e +-------------------------------------------+------------------------------ s | PIGMENT | VEHICLE t +-------------------------------------------+------------------------------ |Corroded White Lead |Linseed Oil N | |Sublimed White Lead | |Turpentine o | | |Zinc Oxide | |Drier . | | | |Calcium Carbonate | | |Turpentine | | | | |Aluminum and | | |and | | | | |Magnesium Silicate | | |j.a.pan | | | | | |Barytes | | | |Water | | | | | | |Silica | | | | |Turpentine | | | | | | | |Inert | | | | |and Benzine | | | | | | | | |Magnesium | | | | |j.a.pan Drier | | | | | | | | |Silicate | | | | | |Drier | | | | | | | | | |Calcium| | | | | | |Vola- | | | | | | | | | |Sul- | | | | | | |tile | | | | | | | | | |phate | | | | | | |Oil | | | | | | | | | | |Zinc| | | | | | | |[B]

| | | | | | | | | | |Lead| | | | | | | | ---+----+---+----+---+--+--+----+--+---+--+----+----+----+--+----+--+--+--+--- 1| 30 | --|70 |-- |--|--| -- |--|-- |--| -- |93 | 7 |--| -- |--|--|--|-- 2| 50 | --|50 |-- |--|--| -- |--|-- |--| -- |86 | -- |10| 4 |--|--|--|-- 3| 20 | 20|50 |10 |--|--| -- |--|-- |--| -- |90 | -- |--| -- |10|--|--|-- 4|48.5| --|48.5| 3 |--|--| -- |--|-- |--| -- |83 | -- |--| -- |17|--|--|-- 5| 22 | --|50 | 2 |26|--| -- |--|-- |--| -- |90 | -- |--| -- |--|10|--|-- 6| -- | --|64 |-- |--|36| -- |--|-- |--| -- |98 | -- |--| -- |--|--| 2|-- 7| 37 | --|63 |-- |--|--| -- |--|-- |--| -- |85 |13 |--| 2 |--|--|--|-- 8| 38 | --|48 |-- |--|--|14 |--|-- |--| -- |91 | 9 |--| -- |--|--|--|-- 9| -- | --|73 | 2 |--|--|25 |--|-- |--| -- |66 |-- |--|12 |22|--|--|-- 10| 44 | --|46 | 5 |--|--| -- |--|-- |--| -- |86.0|12.5|--| 1.5|--|--|--|-- 11| 50 | --|50 |-- |--|--| -- |--| 5 |--| -- |78 |22 |--| -- |--|--|--|-- 12| 60 | --|34 |-- |--|--| -- | 6|-- |--| -- |91 | 7 |--| 2 |--|--|--|-- 13| -- | 60|27 | 3 |--|--| -- |--|10 |--| -- |90 | -- |--| -- |--|10|--|-- 14| 25 | 20|25 | 5 |--|--| -- |--|-- |25| -- |90 | -- | 6| -- |--|--|--| 4 15| -- | 20|40 |10 |--|--| -- |--|-- |--| 30 |90 | -- | 8| 2 |--|--|--|-- 16| 33 | --|33 |-- |--|34| -- |--|-- |--| -- |90 | -- |10| -- |--|--|--|-- 17|100 |(Type A)|-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 18|100 |( " B)|-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 19|100 |( " C)|-- |--|--| -- |--|-- |--| -- | 10 gal. oil |--|--|--|-- | | | | | | | | | | | reduction | | | | 20| -- |100| -- |-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 21| -- | --|100 |-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 22| -- | --| -- |-- |--|--| -- |--|-- |--|100 | -- | -- |--| -- |--|--|--|-- 23|100 |(Type C)|-- |--|--| -- |--|-- |--| -- | 5-1/2 gal. oil reduction for | | | | | | | | | | | | priming 24| 37.|7. |25. |20.|--|--|8.42| (Michigan Seal | -- |--| -- |--|--|--|-- | 51 |84 |87 |36 | | | | White Lead) | | | | | | | 25| 38.|4. |33. |19.|--|--|3.18|(Railway White| -- | -- |--| -- |--|--|--|-- | 95 |81 |58 |48 | | | | Lead) | | | | | | | | 200|15. | --|-- | 1.|--|--| -- |--| 1.|--|43. |32. | 4. |--| 1. |--|--|--|-- |625 | | |875| | | | |250| |750 |250 |000 | |250 | | | | ===+====+===+====+===+==+==+====+==+===+==+===+====+=====+==+====+==+==+==+===

[B] = Benzine

===+=========+========================================= T | | REPORT OF CONDITION e | +------------+------+------+-------------- s | | | | | t | | | | | | | | | | N | | | | | o | | | | | . | | | | | |CHALKING |CHECKING |HIDING|COLOR |CONDITION FOR | | |POWER | |REPAINTING ---+---------+------------+------+------+-------------- 1|Medium |Considerable|Fair |Fair |Poor surface; | |with lateral| | |too hard | |cracking | | | 2|Medium |Considerable|Good |Fair |Rather poor | |with lateral| | | | |cracking | | | 3|Bad |Medium-- |Good |Good |Fair | |scaling some| | | 4|Medium |Considerable|Good |Good |Medium | |with lateral| | | | |cracking | | | 5|Slight |Slight |Good |Good |Good 6|Medium |Considerable|Medium|Medium|Fair 7|Consider-|Present; |Fair |Fair |Poor |able |long cracks | | | 8|Slight |Surface |Good |Good |Fair | |checking | | | 9|Not |Considerable|Medium|Good |Medium |evident |with lateral| | | | |cracking | | | 10|Medium |Very slight |Good |Good |Good 11|Slight |Lateral |Fair |Fair |Fair | |cracking | | | 12|Consider-|Present with|Fair |Fair |Not very good |able |slight | | | | |cracking and| | | | |scaling | | | 13|Medium |Surface |Good |Good |Good | |checking | | | | |only | | | 14|Consider-|Considerable|Medium|Fair |Medium; some |able |with lateral| | |washing shown | |cracking | | | 15|Medium |Medium |Good |Good |Medium 16|Medium |Slight; some|Fair |Good |Medium | |sh.e.l.ling | | | 17|Bad |Alligator- |Good |Fair |Poor | |ing; deep | | | | |checking | | | 18|Bad |Alligator- |Fair |Fair |Poor | |ing; deep | | | | |checking | | | 19|Bad |Deep |Good |Fair |Poor 20|Consider-|Slight |Good |Fair |Fair |able | | | | 21|Not |Consider- |Fair |Good |Poor |evident |able; slight| | | | |cracking; | | | | |scaling | | | 22|Medium |Lateral |Good |Good |Fair | |cracking; | | | | |split | | | 23|Bad |Medium deep |Good |Good |Fair 24|Consider-|Slight; |Fair |Good |Good |able |lateral | | | | |cracking | | | 25|Consider-|Some; |Fair |Good |Excellent |able |lateral | | | | |cracking | | | 200|Medium |Bad cracking|Good |Good |Fair ===+=========+============+======+======+==============

"As before stated, the committee believes that a serious mistake was made on the test fence in painting out the leads and other formulas on the various woods without any special attention to reduction to suit the nature of the wood, thus accounting largely for the difference of the wearing of the paints on the different woods.

"The reduction of the white leads especially was to be criticised in these tests, in many cases too much oil and not sufficient turpentine being present to cause penetration.

"The application of paint to cedar was satisfactory in most all cases, and this wood showed much better results than the other woods upon the fences. The exudation of resinous pitch on the hard pine was extremely serious, in some cases coming through the paint in large streaks, causing bad results.

"It is to be regretted that the house repainting tests which were conducted are of no special value, inasmuch as no information is on file as to the composition of the old paints originally on the houses before the application of the test paints. Imperfections in the old coating, such as excessive chalking, deep checking, scaling, rosin exudations, etc., affected the subsequent coats in such a manner as to prevent any knowledge of where the new and old paint troubles began. The committee, therefore, omitted a detailed inspection of such tests.

"Examination of the three houses which were painted over new wood showed results which correspond with the results obtained from the fence tests.

That is, they showed the ultimate value of high type mixtures of several pigments over one pigment alone. These tests seem to indicate that very good results can be secured from most of the paints sold in North Dakota. If the consumer or householder would exercise more care in the selection of wood and preparation of surfaces, with due regard to the proper reduction for various coats, more satisfactory results would be obtained.

"From an examination of certain paints on the 1908 fence containing petroleum spirits, it would appear that this paint thinner is of value, and in the face of conditions such as are presented by the present scarcity of turpentine, the use of petroleum spirits in moderate quant.i.ty would be justified."

NORTH DAKOTA TESTS

[Ill.u.s.tration: 1. Formula No. 21, Section 31, on 1907 Fence]

[Ill.u.s.tration: 2. Section 80, on 1908 Fence]

[Ill.u.s.tration: 3. Formula No. 6, Section 9, on 1907 Fence]

[Ill.u.s.tration: 4. Formula No. 2, Section 3, on 1907 Fence]

[Ill.u.s.tration: 5. Formula No. 1, Section 1, on 1907 Fence]

[Ill.u.s.tration: 6. Formula No. 14, Section 21, on 1907 Fence]