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MNL17-EB/Jun
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Ashton ~

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Definition and Scope
THIS CHAPTERIS CONCERNEDwith the selection and use of
procedures for testing organic finishes intended for use on
interior surfaces, exterior surfaces, or both interior and exterior surfaces
...
"
"paint, n, specific--a classification sometimes employed
to distinguish pigmented drying oil coatings ("paints")
from synthetic enamels and lacquers
...
For example, an aluminum finish may be used for application to aluminum objects
or it may contain aluminum pigment and be used on various
objects
...
Rather, an architectural coating
is for the type of structure customarily designed by architects
in contrast to those designed by civil engineers
...

The definition for architectural coating given in the two
ASTM standards, D 5146 and D 5324, referred to below, combines the definition from ASTM D 16 with that in the FSCT's
Paint/Coatings Dictionary [1] as follows:
"Organic coatings intended for on-site application to interior or exterior surfaces of residential, commercial, institutional, or industrial buildings, in contrast to industrial coatings
...
Often called Trade
Sales Coatings
...
(2) A liquid, liquefiable or mastic composition which is converted to a solid protective, decorative, or functional adherent film after application as a
thin layer
...
Any pigmented liquid, liquefiable, or
mastic composition designed for application to a substrate in a thin layer which is converted to an opaque
solid film after application
...
"

As with many types of coatings, the titles of the two ASTM
guides reflect the two main composition categories--waterborne and solvent-borne
...


Hence, clear varnishes and lacquers are familiar types of
coatings that are not, strictly speaking, paints
...
"
Since there are many different types of coatings, it is useful
to classify them into groups
...
Appearance--clear, high gloss, metallic, pigmented, red,
stain, textured, etc
...
Composition--alkyd, latex, oil, solvent-borne, zinc-rich,
etc
...


1
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2
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3
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4
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696
Copyright9 1995 by ASTMInternational

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org

CHAPTER 59--ARCHITECTURAL COATINGS
Each of these finishes is intended for application by brushing,
rolling, spraying, or other means to the substrates appropriate to its end use, which may include wood, plaster, masonry,
wallboard, steel, previously painted surfaces, and other architectural suhstrates
...
" Such coatings are
extra-durable systems applied as continuous films that cure
to hard, tough finishes that are resistant to abrasion, staining,
chemicals, detergents, and mildew growth
...
Other polymer types are not excluded from this high-performance area if they can be formulated into coatings that meet purchaser performance requirements
...


ASTM GUIDES TO TESTING
ARCHITECTURAL COATINGS
The ASTM guides listed below provide systematic compilations of relevant properties, the related test methods, and,
where possible, typical values, for the guidance of users
...
The nature of the substrate can affect the application and appearance properties of
a coating, such as uniformity and gloss, and is an important
factor in determining the type of coating to use
...
A primer-sealer may be required for porous substrates,
such as unpainted drywall, new wood, plaster, or porous
masonry
...
Finishes intended only for interior service do not require
resistance to weather factors
...
Low-gloss wall finishes do not need the abrasion resistance
required of floor coatings
...


Substrate Conditions
The condition of the surface is important in determining
the type of coating and surface preparation that might be

697

required
...
The smoothness of
the substrate affects the spreading rate, texture, and final
appearance of the coating
...
Similar failures
can occur where painted lumber is adjacent to damp masonry surfaces
...

However, some degree of weathering of masonry surfaces
may have a beneficial effect on performance by passivating
the surface and changing the alkalinity
...

Surface dampness during application and drying can adversely affect the adhesion of solvent-borne coatings but not
of water-borne coatings
...
Of course, no water-borne coating can be applied at temperatures below the freezing point of
water
...
In
contrast, a shady location, such as on the north side of a
structure or nearby trees and shrubs, can protect the film
from sunlight but it can promote mildew growth
...
g
...


Interior Coatings
The porosity, smoothness, and color of the surfaces are
important factors for both new and repaint jobs
...
If drying temperatures are too
low, long drying times are needed and this can result in
significant dust and dirt accumulation on the film
...
High relative humidity is
also to be avoided when applying both solvent- and waterborne coatings
...


General
It should be recognized that proper surface preparation
and correct application techniques are as important as the
inherent properties of a coating in contributing to adequate
performance
...
After selecting the best material for a given service,
it is essential that the manufacturer's instructions be followed
...
g
...
g
...
The test methods discussed in
this chapter cover practically all of the properties of architectural coatings
...
Coatings intended for exterior use
only or for both exterior and interior uses require certain
properties not relevant to those intended for interior use only
...

V a l u e Judgments
The purchaser should first determine the properties required of a coating and then select only the test methods
appropriate for those properties
...
Since
coating properties frequently tend to oppose each other, such
as low sheen versus good cleansability or good sag resistance
versus good leveling, some properties may need to be less
emphasized if others are to be accentuated
...
No attempt is made herein or
in the ASTM standard guides listed above to indicate relative
importance of the various tests
...


P R O P E R T I E S OF LIQUID COATINGS

the weight by 100 results in g/mL or by 10 yields lb/Imperial
gallon
...
Typical
coating densities are in the range of 10 to 12
...
S, gallon
(1
...
5 kg/L) for water-borne paints
...
S, gallon (0
...
2 kg/L) range due
to the lower density of the solvents used instead of water
...
Other devices and methods for measuring
density are presented elsewhere in the manual
...
In
general the glossier the film, the more detrimental such particles are to appearance
...
They normally occur as a defect in the production process that permits introduction of clumps of dry pigment or foreign matter such as pieces of shipping bags and
the like
...
A typical maximum requirement is 0
...
Objects such as pigment lumps, polymer seeds, etc
...
Linear objects like fiber strings can flow through this
screen and may require other removal methods, such as centrifuging
...
Devices
such as centrifuges are more expensive and more time consuming than screens, but they often yield more accurate
results than the latter
...
In production control, density provides
a simple check against the formula weight since any significant deviation indicates an incorrectly made or mixed coating, including the presence of entrapped air
...
Laboratory pycnometers
are typically made of glass and have a narrow neck to reduce
evaporation of volatile fluids
...
It is
a plastic or metal wide-mouth cylinder, a shape convenient
for handling viscous coatings and polymers
...
454 mL so that the
weight in grams required to fill the cup divided by 10 is the
density in lb/U
...
Also, if pigment agglomerates
exceed the thickness of the dry film, it will be impossible to
obtain a coating of the desired degree of smoothness
...
The depth at which continuous groupings of
particles or agglomerates protrude through the surface of the
wet film is taken as the fineness of dispersion value
...
Lower gloss finishes do
not generally require a fine dispersion, so they might have a
dispersion value of 2
...

Some interior flat latex paints have finenesses as low as 3
...
Most interior semigloss and
gloss enamels have a fineness value of about 1
...
3 mils
(40 to 7/zm or 5 to 7
...

Information about conducting the test appears in ASTM Test
Method for Fineness of Dispersion of Pigment-Vehicle Systems (D 1210)
...
The organic solvents used in these coatings have
characteristic temperatures at which their vapors support
combustion
...
It is also used to determine conditions of
storage to meet fire regulations and the U
...
Occupational
Safety and Health Act (OSHA)
...
For pigmented and/or viscous materials that require
stirring to obtain consistent results, ASTM Test Methods for
Flash Point by Pensky-Martens Closed Tester (D 93, Method
B) is specified
...
Since
solvents do not require stirring, they are generally tested with
ASTM Test Method for Flash Point by Tag Closed Tester
(D 56)
...
Since this routine does not detect
inadvertent contamination, large-volume purchases are
sometimes tested for flash point, in some cases after thinning
at the job site
...


Volatile organic compounds evaporate into the atmosphere
when coatings dry and/or cure, and they are believed to contribute significantly to air pollution
...
In addition, many types of coatings that cure by chemical reaction,
in contrast to those that dry solely by evaporation of organic
solvent or water, generate volatile molecules such as formaldehyde and related compounds
...
e
...
Some of the VOCs have also been related to the destruction of ozone in the upper atmosphere
...

Such exempt solvents are very few and within a relatively
short time there may be none at all
...
Examples of
such restrictions are maxima of 350 g/L for "clear wood finishes" and 400 g/L for quick-drying enamels
...
S
...

ASTM Practice for Determining Volatile Organic Compound
(VOC) Content of Paints and Related Coatings (D 3960),
U
...
A
...


Odor

D i l u t i o n Stability

Some solvent combinations produce undesirable odors,
particularly when painting indoors with inadequate ventilation and at elevated temperatures
...
Latex
or other water-borne coatings, which contain relatively little
if any organic solvent, may contain other ingredients such as
ammonia, residual monomer, etc
...
Hence both solvent- and waterborne coatings should be tested to establish whether the odor
is irritating or merely unpleasant
...
This
method is a comparative procedure for observing characteristic and residual odors of volatile organic solvents and is not
designed to determine subtle odor differences or odor intensity, There are hazards associated with the test, and the Hazards section of the method should be read and heeded when
the test is used
...
S
...
141 by the U
...
Department of Defense
...
It is, therefore, desirable to
establish that a coating and the specified thinner are compatible and the reduced material is stable
...
Method 4203 in FTMS
No
...
If there is doubt about the stability,
some of the material is then flowed onto a glass panel where
any incompatibility is more evident
...
Good resistance to absorption (hold-out) is desirable with interior primers and undercoats because it enables
them to seal such surfaces, thus promoting uniformity in
both gloss and color of subsequent finish coats
...
In
general, the binders in solvent-borne architectural coatings
tend to penetrate chalk and rust very well owing to their lower
molecular weight in comparison to that of latex binders
...

Method 4421 of FTMS 141 is a roughly quantitative
method for measuring absorption that employs filter paper as
a reproducible porous surface
...
After 3 h, vehicle migration is observed as a spreading circular stain in the paper, and
the mean distance from the rim of the cover is reported as the
degree of absorption or penetration
...
Method 6261 of FTMS 141 is a more
practical procedure than Method 4421, involving application
of the material to an imperfectly primed porous surface and,
after drying, observation for variations in gloss and/or color
...
S
...


Color Compatibility
A colorant sometimes fails to disperse completely and yield
the desired color in a white or tint base owing to poor compatibility that can be related to the colorant (color development), the base (color acceptance), or both
...
Although the problem is generally related to poor dispersability of the colorant, especially those
designed for use with both solvent- and water-reducible coatings, the white pigment in the base may not have been adequately dispersed or may have subsequently flocculated
...
e
...
When both the
colorant and the white are poorly dispersed, the color change
due to shear stress will be some combination of the two
effects
...
In the factory it
causes a loss of monetary value and unpredictable tinting
results
...
This is commonly evaluated by applying the coating with an applicator blade and subjecting a
small area of the drawdown to high shear by finger rubbing
the partially dried film
...
The
color difference can be measured photometrically to obtain
numerical values that are more useful than visual evaluations
for establishing limits for control work
...

In ASTM Test Method for Color Development in Tinted
Latex Paints (D 5326), a portion of the semi-dry film is subjected to closely controlled brushing for development of a
strong shear force
...


Coating Rheology
This term refers to the viscometric characteristics of liquid
coatings
...
Most
architectural coatings are non-Newtonian in character and
have a higher viscosity at low shear rates than at high shear
rates and vice versa
...
Paints that exhibit plastic flow are called Bingham liquids
...
It is possible for a material to
exhibit both plastic flow and thixotropy
...
High viscosity at low shear rates results in poor leveling
and good sag resistance
...
High
viscosity at high shear rates, such as occur during brush
application, results in brush drag or poor brushability
...

The different instrumental test methods used for coatings
are described below
...
The topics of rheology, viscometry, and related characteristics are dealt with on a theoretical, mathematical basis
elsewhere in the manual
...
While it is related to viscosity, consistency does not
distinguish between different viscosity types and does not
determine the quality of a coating
...
The
most common device for measuring the consistency of architectural coatings is the Krebs modification of the Stormer
Viscometer in which a small off-set T-shaped paddle is
immersed to standard depth in the test fluid and rotated at
200 r/min for instruments with a stroboscopic timer and 200
_+ 20 for those without the timer
...
Although the consistency of most architectural coatings is about 150 to 300 g/100 revolutions (72 to 95
KU), a much wider range is possible because of the great

CHAPTER 59--ARCHITECTURAL COATINGS 701
variation that can occur in the rheological properties of these
materials
...
Consistency is determined in accordance with ASTM Test Method
for Consistency of Paints Using the Stormer Viscometer
(O 562)
...
However, they measure viscosity under different shear
rates
...
ASTM Test Method for
Rheological Properties of Non-Newtonian Materials by Rotational (Brookfield) Viscometer (D 2196) employs a rotational
viscometer to measure viscosity at several shear rates to determine the amount of shear thinning and the viscosity
change at low shear rates
...


Sag Resistance
Some coatings sag and form curtains before the film sets
...
Sag resistance is determined
in accordance with ASTM Test Methods for Sag Resistance of
Paints Using a Multinotch Applicator (D 4400)
...
The chart is then hung vertically with the drawdown stripes in a horizontal position
...


Leveling Properties
Leveling is an important property when smooth, uniform
surfaces are to be produced because it affects hiding and
appearance
...
ASTM Test Method for Leveling of Paints
by Drawdown Method (D 4062) is the most recently developed method for evaluating this property
...

After drying, the ridges are compared under a strong oblique
light to a numbered series of plastic levelness standards
...


Package Stability
Since paints normally are not used immediately after manufacture, they must remain stable in the can for some reasonable time
...
However, exposure in uninsulated warehouses or
during shipping to high temperatures in summer or, for
water-dispersed coatings, to low temperatures in winter may
cause unacceptable changes in the products
...


Heat Stability--Exposure to high temperatures can be used
as an accelerated test to predict stability of a packaged coating when stored at normal temperatures or to test for the heat
stability when a material frequently encounters such conditions in service
...
In ASTM
Test Method for Package Stability of Paint (D 1849), the
changes in consistency and certain other properties of the
accelerated aged material are compared to those occurring in
a control kept at normal temperatures for a longer period
...

Settling--Modern coatings are generally resistant to
marked or hard settling, but at times they do exhibit separation and soft settling
...


APPLICATION PROPERTIES
Application or working properties of a coating are generally compared to a standard or described by requirements in
the product specification
...


Brush Application
Brushed films should be smooth and free of seeds and
when applied to vertical surfaces they should show no sagging, color streaking, or excessive brush marks
...
Wall finishes are tested on vertical surfaces and floor coatings on
horizontal surfaces, although evaluation of the latter on vertical surfaces may be necessary to determine performance on
stair risers, railings, posts, etc
...
Even
though the test is subjective, someone experienced in the art
can produce quite consistent results, particularly in the evaluation of drag qualities
...
All other
factors being constant, increased brush drag results in
greater film thickness with consequent improvements in hiding and film durability
...
This can lead to excessive sagging, prolonged
drying time and, in highly pigmented materials, possibly
"mud-cracking" due to excessive thickness
...
When testing a group of coatings, they must all be
of the same type--all water-borne or solvent-borne
...
3 P (0
...
s)
...
This type of application tends to produce some stipple
pattern
...

Since foaming often occurs when water-borne coatings are
roller applied, the amount of foam produced and the number
of craters that remain after the bubbles have broken should
be determined during the test
...
The degree to which a material spatters when roller applied can be determined by the density of
the spatter
...
Any spatter
generated falls on a catch paper and after drying is rated
against photographic standards
...


Spray Application
Architectural coatings are some times applied by spray
...

Spray application properties are determined in accordance
with Method 2131 of FTMS 141
...


Color
The appearance of color is greatly influenced by several
factors
...
The visual appearance of a
colored object illuminated by incandescent light, fluorescent
light, and natural light differs because the spectral composition of the different incident light sources varies
...
The same color in a low-gloss finish
usually appears to differ when in a high-gloss coating even
though instrumentally the colors may be identical
...


Color Differences by Visual Comparison
Visual comparison of colors is fast and often acceptable
even though numerical values are not obtained
...


Color Differences Using Instrumental
Measurements
The difference in color between a product and its standard
can be measured by instrument
...
Color measuring
instruments provide numerical values that can be compared
to subsequent measurements
...
If metamerism is suspected, visual evaluation should be used to verify the results
...
If the paint has suitable
touch-up properties, additional material can be applied to
these areas only, instead of refinishing the complete object-wall, side of building, etc
...
Differences in these properties are often caused by
short wet-edge time, poor leveling on recoat, and pigment
orientation or flotation during and after application
...


APPEARANCE OF THE DRY FILM
Specimens for evaluating appearance properties should
conform to ASTM Practice for Selection of Coating Specimens for Appearance Measurements (D 3964)
...
It is usually assigned a value in specifications for
white and pastel shades with a typical range of 76 to 86% for
white finishes
...


Gloss
Gloss is a measure of the capability of a coating surface to
reflect light in a mirror-like (specular) manner, i
...
, light
strikes the surface and is reflected at the equal but opposite
angle
...
The gloss of some coatings

CHAPTER 59--ARCHITECTURAL COATINGS
varies greatly with the angle of incidence, so that a complete
description of their gloss would require measurements to be
made over a wide range of angles
...
The 85 ~ angle is a very low angle of
illumination (a "grazing" angle of 5~ and viewing the surface
and gloss at this angle is called "sheen
...
Hence, there is considerable overlap among the gloss classifications in common
usage
...
Low or uneven
gloss readings are indicative of this defect
...
Floor enamels
generally have a high (90 + ) gloss reading when first applied,
but this decreases with time and traffic
...


Sheen, 85 ~ Gloss
Although low-gloss paints with good uniformity of appearance at low viewing angles often have little sheen and those
with good cleansability usually have moderate sheen, this is
not always the case so that sheen should not be used as a
measure of other paint properties
...
Most flat wall paints
have a sheen of about 1 to 10 whereas velvets or eggshells
range from 15 to 35
...
ASTM Test Method
for Hiding Power of Paints by Reflectometry (D 2805) is precise and gives an absolute rather than a comparative result
...
Film thickness is precisely measured and film opacity is instrumentally determined
...
However, results
are affected by the flow and leveling of the paint
...
Although other tools may be used, the method
describes use of a roller to coat a 6-ft2 (0
...
The test is intended to demon-

703

strate the hiding obtainable when the coatings are applied by
experienced workers
...
Dry abrasion resistance is
determined in accordance with ASTM Test Method for Abrasion Resistance of Organic Coatings by Air Blast Abrasive
(D 658), ASTM Test Method for Abrasion Resistance of Organic Coatings by Falling Abrasive (D 968), and ASTM Test
Method for Abrasion Resistance of Organic Coatings by the
Taber Abraser (D 4060)
...
In the
case of the Taber test, a weighted wheel that has abrasive
embedded in a resilient rubber matrix is used
...
Interlaboratory agreement is
improved significantly when rankings are used in place of
numerical values
...
It is evaluated by
many different procedures, almost all of which are not completely satisfactory because the removal force is not applied
at the coating-substrate interface but at the coating surface
...
When muhicoat systems are involved, the failure
can also be between coats
...

The test most commonly used with coatings is ASTM Test
Methods for Measuring Adhesion by Tape Test (D 3359)
...
The more quantitative procedure involves
making a six- or eleven-cut lattice in the film
...
If a tool that makes all cuts in one direction is
available, the test can be made in the field
...
Since the cuts~ must be
made through the coating to the substrate, the latter must be
sufficiently hard to resist the cutting tool
...

Another laboratory method that requires a relatively hard
substrate is ASTM Test Method for Adhesion of Organic
Coatings by Scrape Adhesion (D 2197)
...
The advantage of this procedure is that the results
are numerical
...
Thus, it is difficult to push panels under the loaded
loop without causing it to skip along the coating surface
...
The procedure comprises adhering a metal stud to the
coating surface with an adhesive, curing the latter, attaching
the test apparatus to the stud, and applying a perpendicular
force that is increased until either the coating is detached, a
specified value is reached, or the adhesive fails
...
As a result, failure can occur within the substrate, the coating, or the adhesive, or at the stud-adhesive
interface, the adhesive-coating interface, or even the coatingsubstrate interface
...
They can, however, be used in
the laboratory unless the adhesive bond strength is very high
...


Wet Adhesion
It is essential that a finish tightly adhere to a given substrate
or primer under the wet conditions of washing or scrubbing
...
In it, two parallel cuts are made 1 in
...
Then masking tape, which changes
markedly in adhesiveness with time, is pressed against the
coating surface with a roller instead of semitransparent tape
being rubbed with a pencil eraser
...


Flexibility
Elongation is a measure of a coating's flexibility
...

(3
...
However, interior flat and eggshell water-borne finishes usually pass at
1/4 in
...
4 mm), while solvent-borne coatings of the same
category may pass only a 1A-in
...
7-mm) bend
...
However, measuring elongation directly with a tensile testing machine as
described in ASTM Test Method for Tensile Properties of
Organic Coatings (D 2370) is a much more discriminating
way of estimating the flexibility retention of exterior coatings

[4]
...
In ASTM Test Method for Effect of Household
Chemicals on Clear and Pigmented Organic Finishes
(D 1308), the resistance may be evaluated with household
items ranging from cold water, to detergent solutions, to

staining materials such as mustard
...


Interior Finishes

Block Resistance
This is an important property for interior semigloss and
gloss finishes since it governs the resistance of dried coating
surfaces to sticking together when stacked or placed in contact with each other
...
Such blocking is dependent on
the hardness of the coating and the applied pressure, temperature, humidity, and time while the surfaces are in contact
...


Print Resistance
The ability of a coating to resist printing is important because its appearance is adversely affected if the surface texture is modified by contact with another surface, particularly
one with a pattern
...
The tendency for a film to "print" is often a function of the hardness
of the coating and the applied pressure, humidity, and time
while the surfaces are in contact
...
The test is accelerated by
placing the assembly in an oven at 140~ (60~ for an hour
...


Film Porosity
The more porous a coating, the worse are its cleansability
and enamel holdout
...


Washability and Cleansability
The capability of satisfactorily removing marks without
damaging the film is essential for good performance of interior finishes
...
Washability is evaluated by determining the resistance of
the film to wet erosion either by visual assessment or measured film loss
...
Frequently the difference between the two terms,
"cleansability" and "washability," is not clearly understood so
that there is confusion as to what is really being tested [5]
...
" In general, the pre-

CHAPTER 59--ARCHITECTURAL COATINGS
cision of b o t h types of test is p o o r b e c a u s e several properties,
such as hardness, w a t e r a n d detergent resistance, cohesion,
a n d adhesion, are involved, a n d the end-point, except for the
wet a b r a s i o n m e t h o d , is r a t h e r indefinite
...
" ASTM Test M e t h o d for
Scrub Resistance of I n t e r i o r Latex Flat Wall Paints (D 2486)
was developed for interior latex flat wall p a i n t s b u t can be
a p p l i e d to coatings of a l m o s t any type, In the test, the coating
is applied to a b l a c k plastic panel that, during s c r u b b i n g with
a nylon b r u s h a n d abrasive cleaning agent, is raised b y a
n a r r o w shim to c o n c e n t r a t e the test area
...
I n t e r i o r latex low-gloss finishes
can vary in scrub resistance from less t h a n 100 to m o r e t h a n
1000 cycles
...
In the
original method, the loss p e r 100 cycles to erode the film
a l m o s t to exposure of the b l a c k substrate was calculated on
the basis of either weight or volume
...


Cleansability
The older of the m e t h o d s for this type m e a s u r e m e n t , ASTM
D 3450, is s i m i l a r to the w e t - a b r a s i o n method, ASTM D 4213,
except a sponge is used with either the n o n a b r a s i v e o r abrasive cleaning agent to r e m o v e a c a r b o n black-oil stain
...
In ASTM Test M e t h o d for
Practical W a s h a b i l i t y [sic] of Organic Coatings (D 4828), num e r o u s staining a n d soiling agents found in service, a n d commercial abrasive or n o n a b r a s i v e cleansers, as well as the
s t a n d a r d i z e d cleaning agents, can be used
...


Exterior Coatings
Adhesion to Chalky Surfaces
Latex p a i n t s generally have little ability to p e n e t r a t e powdery substrates
...
However, certain latexes do exist that are designed to

705

a d h e r e well to chalky surfaces a n d thus do not require modification
...
The i n d u s t r y generally uses a pressure-sensitive tape to test for this property
...
M e t h o d 6301 of FSTM 141
describes a similar m e t h o d b u t it includes w a t e r exposure
...
Exterior exposure,
p a r t i c u l a r l y u n d e r a n overhang (soffit), should indicate in a
relatively short time (about one year) a paint's t e n d e n c y to
collect dirt w h e n evaluated in a c c o r d a n c e with ASTM Test
M e t h o d for Quantifying Dirt Collection on Coated Exterior
Panels (D 3719)
...
This
type of a t m o s p h e r e m a y be present n e a r industrial o r o t h e r
p o l l u t e d areas a n d can cause a p a i n t to yellow or d a r k e n in as
little t i m e as overnight
...
Then expose one plate in a moist a t m o s p h e r e of
h y d r o g e n sulfide for 18 h
...
The color difference
should not exceed that w h i c h exists b e t w e e n two plates
coated with a p a i n t m a d e with t i t a n i u m dioxide pigment,
lead-free zinc oxide, r a w o r refined linseed oil, and sufficient
cobalt a d d e d for drying purposes, and similarly treated
...
, Federation of Societies for Coating Technology, Blue Bell, PA 19422, 1978
...
J
...
, ASTM, Philadelphia, PA 19103, 1993
...

[4] Ashton, H
...
, "Flexibility and its Retention in Clear Coatings
Exposed to Weathering," Journal of Coatings Technology, Vol
...
653, June 1979, p
...

[5] Feinherg, H
...
45

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