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Paint & Coatings
| Painting and finish coating application differs widely based upon
the materials used, and the geographical are the paint will be applied
(due to EPA air quality restrictions). The procedures used to select and
apply coatings should be based upon the criteria for each Transit Authority.
Typical paints used are automotive grade urethane (color coat/clear
coat) for exterior, cosmetic finishes, urethane or epoxy for utility,
non-cosmetic finishes, and electrically nonconductive for the
inside of electrical lockers (usually white).
Powder coating is also commonly used, but should be restricted
to epoxy for interior applications, and polyester for exterior
applications.
The standards referenced below are typical for surface preparation and
finished coating quality evaluation. |
| Standard: |
ASTM D2200 - Standard Pictorial
Surface Preparation Standards for Painting Steel Surfaces
| | Purpose: |
The visual surface preparation standards consist of a series of
color prints available as separate publications. Three different sets
of photographs are described in this standard, designated as Method
A (ISO/Swedish Standard) and Method B and C (SSPC Standards). The
three methods differ in the depiction of the initial surface, in the
definition and depiction of the cleaning conditions, and in the number
of cleaning methods included. Because of these differences, the specifier
should state whether Method A, Method B, or C should be used.
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| Criteria: |
Specify the standard name, method selected, and desired cleaning
level
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| Usage: |
Abrasive blasting shall be done according to ASTM D 2200, the
surface finish shall be Near White Metal, using Method A, or Method
B, SSPC SP-10.
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| Standard: |
ASTM D1186 - Standard Test
Methods for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic
Coatings Applied to a Ferrous Base
| | Purpose: |
These test methods cover the nondestructive measurement of the
dry film thickness of nonmagnetic coatings applied over a ferrous
base material using commercially available test instruments. The test
methods are intended to supplement manufacturers instructions for
the manual operation of the gages and are not intended to replace
them. They cover the use of instruments based on magnetic measuring
principles only. Test Method A provides for the measurement of films
using mechanical magnetic pull-off gages and Test Method B provides
for the measurement of films using magnetic electronic gages.
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| Criteria: |
Specify standard name, method selected, compliance criteria
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| Usage: |
ASTM D1186, Method x, with a minimum film thickness of xx (or
tolerance)
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| Standard: |
ASTM D1400 - Standard Test
Method for Nondestructive Measurement of Dry Film Thickness of Nonconductive
Coatings Applied to a Nonferrous Metal Base
| | Purpose: |
This test method covers the nondestructive measurement of the
dry film thickness of electrically nonconductive coatings applied
over a nonferrous metal base using commercially available eddy current
instruments. This test method is intended to supplement manufacturers'
instructions for the manual operation of the gages, and is not intended
to replace them.
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| Criteria: |
Specify standard name, compliance criteria
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| Usage: |
ASTM D1400, with a minimum film thickness of xx (or tolerance)
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| Standard: |
ASTM D3359 - Standard Test
Methods for Measuring Adhesion by Tape Test
| | Purpose: |
These test methods cover procedures for assessing the
adhesion of coating films to metallic substrates by applying
and removing pressure-sensitive tape over cuts made in the
film. Test Method A is primarily intended for use at job
sites while Test Method B is more suitable for use in the
laboratory. Also, Test Method B is not considered suitable
for films thicker than 5 mils (125µm).
It is important when conducting this test that a suitable,
and fresh, testing tape be used to get repeatable results.
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| Criteria: |
Specify standard name, desired adhesion classification, and test
tape type.
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| Usage: |
Testing for adhesion between the paint and the substrate surface
shall conform to ASTM D 3359, 3A Classification, using Permacell #99
adhesion test tape
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| Standard: |
ASTM D523 -Standard Test Method
for Specular Gloss
| | Purpose: |
This test method covers the measurement of the specular gloss
of nonmetallic specimens for glossmeter geometries of 60, 20, and
85°. Cosmetic coatings of paint typically have specified gloss level
for the appearance desired.
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| Criteria: |
Specify standard name, desired gloss level, and gloss meter angle.
(See table for typical values)
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| Usage: |
ASTM D523, 95% gloss at 60 degree axis angle
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| Standard: |
ASTM D 2244 - Standard Practice
for Calculation of Color Tolerances and Color Differences from Instrumentally
Measured Color Coordinates
| | Purpose: |
This practice covers the calculation, from instrumentally measured
color coordinates based on daylight illumination, of color tolerances
and small color differences between opaque specimens such as painted
panels, plastic plaques, or textile swatches. (not for use with metallic
colors)
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| Criteria: |
Specify standard name, desired color match level. (Note: the output
of this test is typically a graph, acceptability of the color match
should be agreed upon by the client and contractor)
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| Usage: |
ASTM D 2244, acceptability criteria TBD
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| Standard: |
Powder Coating Institute, Gloss
Level Standard
| | Purpose: |
This is an industry standard to identify the various
gloss levels of powder coated products. The gloss range
is defined by 10 standards ranging from; 1= heavy orange
peel to 10=mirror finish. The standards are a series of
sample finishes used for comparing the sample level to the
coated product. |
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| Criteria: |
Specify the standard name, and desired gloss level
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| Usage: |
Powder Coating Institute, Gloss Level Standard(s) - 7 to 10 (typical
for interior components)
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| The gloss levels within this table are ranges for common
terminology, and defined according to the following criteria based
upon the ASTM D 523 - 60° axis angle with equivalents shown for
80° and 20°. |
| Glossmeter setting |
20 degree
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60 degree
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85 degree
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| Common Definition - High Gloss
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85-90% |
90-95% |
95-100%
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| Common Definition - Semi Gloss
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0-10% |
20-30% |
50-60% |
| Common Definition - Flat Gloss
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0% |
0-10% |
10-20% |
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