ASTM D3794-22
(Guide)Standard Guide for Testing Coil Coatings
Standard Guide for Testing Coil Coatings
SIGNIFICANCE AND USE
4.1 This guide represents a collection of pertinent ASTM test methods used within the coil coatings industry. In the past coil coaters world wide depended on industry standards written by the National Coil Coating Association. That association, working cooperatively with ASTM, will no longer issue new, nor update old, standards.
SCOPE
1.1 This guide covers procedures for testing coil coatings. The test methods included are listed in Table 1. Where more than one test method is listed for the same characteristic, no attempt is made to indicate superiority of one method over another. Selection of test methods to be followed must be governed by the requirements in each individual case, together with agreement between the producer and user.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
- Status
- Published
- Publication Date
- 14-Jun-2022
- Technical Committee
- D01 - Paint and Related Coatings, Materials, and Applications
- Drafting Committee
- D01.53 - Coil Coated Metal
Relations
- Effective Date
- 01-Apr-2024
- Effective Date
- 01-Apr-2024
- Effective Date
- 01-Feb-2024
- Effective Date
- 01-Feb-2024
- Effective Date
- 15-Jan-2024
- Effective Date
- 01-Jan-2024
- Effective Date
- 01-Dec-2023
- Effective Date
- 01-Dec-2023
- Effective Date
- 01-Dec-2023
- Refers
ASTM E1164-23 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation - Effective Date
- 01-Nov-2023
- Refers
ASTM D4147-18(2023) - Standard Practice for Applying Coil Coatings Using Wire-Wound Drawdown Bars - Effective Date
- 01-Oct-2023
- Refers
ASTM D4287-00(2023) - Standard Test Method for High-Shear Viscosity Using a Cone/Plate Viscometer - Effective Date
- 01-Oct-2023
- Refers
ASTM D4214-23 - Standard Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films - Effective Date
- 01-Oct-2023
- Effective Date
- 01-Sep-2023
- Effective Date
- 01-Jun-2020
Overview
ASTM D3794-22: Standard Guide for Testing Coil Coatings is an internationally recognized guideline developed by ASTM International. This standard compiles essential ASTM test methods used within the coil coatings industry, providing a comprehensive framework for evaluating the physical, chemical, and performance properties of coil-coated materials. Coil coatings are applied to continuous metal coil stock and must meet stringent quality, durability, and performance requirements, making standardized testing crucial for manufacturers and users alike.
ASTM D3794-22 aligns with global principles of standardization and replaces many earlier industry-specific standards, offering a harmonized approach for selecting and executing appropriate test methods for coil coatings. The standard covers various aspects such as preparation, testing protocols, and agreement requirements between producers and users, ensuring that test methods are relevant, reliable, and practical for contemporary industrial needs.
Key Topics
Scope of Testing: Details procedures for evaluating liquid coatings properties, metal pretreatment, panel preparation, physical and radiative properties, weathering, and corrosion resistance.
Testing Methods Selection: Provides flexibility by listing multiple test methods for the same attribute without prescribing the superiority of one over another. Selection depends on specific project or product requirements and mutual agreement.
Measurement Precision: Stresses accurate measurement of key attributes like viscosity, film thickness, color, gloss, hardness, flexibility, adhesion, and solvent resistance using SI units as standard.
Safety and Compliance: Emphasizes the user's responsibility to address safety, health, and environmental considerations and ensure compliance with applicable regulations when implementing test procedures.
International Applicability: Developed according to World Trade Organization (WTO) guidelines, making it suitable for use in global markets.
Applications
ASTM D3794-22 serves as a foundational document for a wide range of stakeholders in the coil coating industry:
Manufacturers: Utilize the standard for quality control, product development, and process optimization. Testing ensures coil-coated products meet customer specifications and regulatory requirements.
Product Specifiers and Engineers: Reference the guide to verify performance characteristics such as adhesion, durability, weather resistance, and appearance of coil-coated metal components in construction, automotive, and appliance industries.
Laboratories: Implement standardized procedures for testing physical, chemical, radiative, and weathering properties of coil coatings. It streamlines the comparison and acceptance of test results across different facilities and regions.
Quality Assurance: Provides a basis for audits, conformity assessment, and supplier qualification, leveraging recognized methods like dry film thickness measurement, mandrel bend test, specular gloss, accelerated weathering, and corrosion resistance evaluation.
Research and Development: Facilitates the evaluation of new formulations and process modifications, supporting innovation and improved performance in coil-coated products.
Related Standards
ASTM D3794-22 references a broad suite of ASTM standards for testing coil coatings, including but not limited to:
- ASTM D1005 – Measurement of dry-film thickness of organic coatings
- ASTM D3363 – Pencil hardness test for film hardness
- ASTM D3359 – Adhesion by tape test
- ASTM D2794 – Impact resistance of organic coatings
- ASTM D523 – Measurement of specular gloss
- ASTM B117 – Operating salt spray (fog) apparatus for corrosion resistance
- ASTM D2247 / D4587 / G151 / G155 – Accelerated weathering and humidity resistance
- ASTM D1210 – Fineness of dispersion of pigment-vehicle systems
- ASTM E70 – pH measurement
- ASTM D3960 – Determining volatile organic compound (VOC) content
These related standards enable consistent application, validation, and benchmarking of test results, supporting best practices in coil coating evaluation.
Keywords: ASTM D3794-22, coil coating testing, coil coatings, standardized test methods, quality control, metal substrate preparation, physical properties, accelerated weathering, adhesion testing, corrosion resistance, coil-coated metals, industrial coatings, ASTM standards, global compliance.
Frequently Asked Questions
ASTM D3794-22 is a guide published by ASTM International. Its full title is "Standard Guide for Testing Coil Coatings". This standard covers: SIGNIFICANCE AND USE 4.1 This guide represents a collection of pertinent ASTM test methods used within the coil coatings industry. In the past coil coaters world wide depended on industry standards written by the National Coil Coating Association. That association, working cooperatively with ASTM, will no longer issue new, nor update old, standards. SCOPE 1.1 This guide covers procedures for testing coil coatings. The test methods included are listed in Table 1. Where more than one test method is listed for the same characteristic, no attempt is made to indicate superiority of one method over another. Selection of test methods to be followed must be governed by the requirements in each individual case, together with agreement between the producer and user. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
SIGNIFICANCE AND USE 4.1 This guide represents a collection of pertinent ASTM test methods used within the coil coatings industry. In the past coil coaters world wide depended on industry standards written by the National Coil Coating Association. That association, working cooperatively with ASTM, will no longer issue new, nor update old, standards. SCOPE 1.1 This guide covers procedures for testing coil coatings. The test methods included are listed in Table 1. Where more than one test method is listed for the same characteristic, no attempt is made to indicate superiority of one method over another. Selection of test methods to be followed must be governed by the requirements in each individual case, together with agreement between the producer and user. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ASTM D3794-22 is classified under the following ICS (International Classification for Standards) categories: 87.040 - Paints and varnishes. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D3794-22 has the following relationships with other standards: It is inter standard links to ASTM D1824-24, ASTM D1823-24, ASTM D2369-24, ASTM D6665-24, ASTM D2794-93(2024), ASTM E70-24, ASTM E84-23d, ASTM D822-23, ASTM D5031-23, ASTM E1164-23, ASTM D4147-18(2023), ASTM D4287-00(2023), ASTM D4214-23, ASTM E84-23c, ASTM D1212-91(2020). Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM D3794-22 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3794 − 22
Standard Guide for
Testing Coil Coatings
This standard is issued under the fixed designation D3794; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D522 Test Methods for Mandrel Bend Test of Attached
Organic Coatings
1.1 This guide covers procedures for testing coil coatings.
D523 Test Method for Specular Gloss
The test methods included are listed in Table 1. Where more
D610 Practice for Evaluating Degree of Rusting on Painted
than one test method is listed for the same characteristic, no
Steel Surfaces
attempt is made to indicate superiority of one method over
D660 Test Method for Evaluating Degree of Checking of
another. Selection of test methods to be followed must be
Exterior Paints
governed by the requirements in each individual case, together
D661 Test Method for Evaluating Degree of Cracking of
with agreement between the producer and user.
Exterior Paints
1.2 The values stated in SI units are to be regarded as
D714 Test Method for Evaluating Degree of Blistering of
standard. The values given in parentheses are for information
Paints
only.
D822 Practice for Filtered Open-Flame Carbon-Arc Expo-
1.3 This standard does not purport to address all of the
sures of Paint and Related Coatings
safety concerns, if any, associated with its use. It is the
D823 Practices for Producing Films of Uniform Thickness
responsibility of the user of this standard to establish appro-
of Paint, Coatings and Related Products on Test Panels
priate safety, health, and environmental practices and deter-
D870 Practice for Testing Water Resistance of Coatings
mine the applicability of regulatory limitations prior to use.
Using Water Immersion
1.4 This international standard was developed in accor-
D968 Test Methods for Abrasion Resistance of Organic
dance with internationally recognized principles on standard-
Coatings by Falling Abrasive
ization established in the Decision on Principles for the
D1005 Test Method for Measurement of Dry-Film Thick-
Development of International Standards, Guides and Recom-
ness of Organic Coatings Using Micrometers
mendations issued by the World Trade Organization Technical
D1014 Practice for Conducting Exterior Exposure Tests of
Barriers to Trade (TBT) Committee.
Paints and Coatings on Metal Substrates
2. Referenced Documents
D1193 Specification for Reagent Water
D1200 Test Method for Viscosity by Ford Viscosity Cup
2.1 ASTM Standards:
D1210 Test Method for Fineness of Dispersion of Pigment-
B117 Practice for Operating Salt Spray (Fog) Apparatus
Vehicle Systems by Hegman-Type Gage
B368 Test Method for Copper-Accelerated Acetic Acid-Salt
Spray (Fog) Testing (CASS Test) D1212 Test Methods for Measurement of Wet Film Thick-
ness of Organic Coatings
C1371 Test Method for Determination of Emittance of
Materials Near Room Temperature Using Portable Emis- D1308 Test Method for Effect of Household Chemicals on
someters Clear and Pigmented Coating Systems
C1549 Test Method for Determination of Solar Reflectance
D1474 Test Methods for Indentation Hardness of Organic
NearAmbientTemperature Using a Portable Solar Reflec- Coatings
tometer
D1475 Test Method for Density of Liquid Coatings, Inks,
and Related Products
D1654 Test Method for Evaluation of Painted or Coated
This guide is under the jurisdiction of ASTM Committee D01 on Paint and
Related Coatings, Materials, and Applications and is the direct responsibility of
Specimens Subjected to Corrosive Environments
Subcommittee D01.53 on Coil Coated Metal.
D1729 Practice for Visual Appraisal of Colors and Color
Current edition approved June 15, 2022. Published July 2022. Originally
Differences of Diffusely-Illuminated Opaque Materials
approved in 1979. Last previous edition approved in 2018 as D3794 – 18. DOI:
10.1520/D3794-22.
D1735 Practice for Testing Water Resistance of Coatings
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Using Water Fog Apparatus
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
D1823 Test Method forApparent Viscosity of Plastisols and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Organosols at High Shear Rates by Extrusion Viscometer
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3794 − 22
D1824 Test Method forApparent Viscosity of Plastisols and ing Surfaces (Withdrawn 2000)
Organosols at Low Shear Rates D4585 Practice for Testing Water Resistance of Coatings
D2092 Guide for Preparation of Zinc-Coated (Galvanized)
Using Controlled Condensation
Steel Surfaces for Painting (Withdrawn 2008)
D4587 Practice for Fluorescent UV-Condensation Expo-
D2196 Test Methods for Rheological Properties of Non-
sures of Paint and Related Coatings
Newtonian Materials by Rotational Viscometer
D5031 Practice for Enclosed Carbon-Arc Exposure Tests of
D2197 Test Method for Adhesion of Organic Coatings by
Paint and Related Coatings
Scrape Adhesion
D5178 Test Method for Mar Resistance of Organic Coatings
D2244 Practice for Calculation of Color Tolerances and
D5402 Practice for Assessing the Solvent Resistance of
Color Differences from Instrumentally Measured Color
Organic Coatings Using Solvent Rubs
Coordinates
D5531 GuideforPreparation,Maintenance,andDistribution
D2247 Practice for Testing Water Resistance of Coatings in
of Physical Product Standards for Color and Geometric
100 % Relative Humidity
Appearance of Coatings
D2248 PracticeforDetergentResistanceofOrganicFinishes
D5723 Practice for Determination of Chromium Treatment
D2369 Test Method for Volatile Content of Coatings
Weight on Metal Substrates by X-Ray Fluorescence
D2454 Practice for Determining the Effect of Overbaking on
D5796 TestMethodforMeasurementofDryFilmThickness
Organic Coatings
of Thin-Film Coil-Coated Systems by Destructive Means
D2697 Test Method for Volume Nonvolatile Matter in Clear
Using a Boring Device
or Pigmented Coatings
D2794 Test Method for Resistance of Organic Coatings to D5894 Practice for Cyclic Salt Fog/UV Exposure of Painted
the Effects of Rapid Deformation (Impact) Metal, (Alternating Exposures in a Fog/Dry Cabinet and a
D2803 Guide for Testing Filiform Corrosion Resistance of
UV/Condensation Cabinet)
Organic Coatings on Metal
D6093 Test Method for Percent Volume Nonvolatile Matter
D3003 Test Method for Pressure Mottling and Blocking
in Clear or Pigmented Coatings Using a Helium Gas
Resistance of Organic Coatings on Metal Substrates
Pycnometer
D3134 Practice for Establishing Color and Gloss Tolerances
D6491 Practice for Evaluation of Aging Resistance of Pre-
D3170 Test Method for Chipping Resistance of Coatings
stressed Prepainted Metal In a Dry Heat Test
D3278 Test Methods for Flash Point of Liquids by Small
D6492 Practice for Detection of Hexavalent Chromium On
Scale Closed-Cup Apparatus
Zinc and Zinc/Aluminum Alloy Coated Steel
D3359 Test Methods for Rating Adhesion by Tape Test
D6578 Practice for Determination of Graffiti Resistance
D3361 Practice for Unfiltered Open-Flame Carbon-Arc Ex-
D6665 Practice for Evaluation of Aging Resistance of Pre-
posures of Paint and Related Coatings
stressed Prepainted Metal in a Boiling Water Test
D3363 Test Method for Film Hardness by Pencil Test
D6695 Practice for Xenon-Arc Exposures of Paint and
D3960 PracticeforDeterminingVolatileOrganicCompound
Related Coatings
(VOC) Content of Paints and Related Coatings
D6906 Test Method for Determination of Titanium Treat-
D4060 Test Method for Abrasion Resistance of Organic
ment Weight on Metal Substrates by Wavelength Disper-
Coatings by the Taber Abraser
sive X-Ray Fluorescence
D4138 Practices for Measurement of Dry Film Thickness of
D6944 Practice for Determining the Resistance of Cured
Protective Coating Systems by Destructive, Cross-
Coatings to Thermal Cycling
Sectioning Means
D4141 Practice for Conducting Black Box and Solar Con- D7091 Practice for Nondestructive Measurement of Dry
centrating Exposures of Coatings Film Thickness of Nonmagnetic Coatings Applied to
D4145 Test Method for Coating Flexibility of Prepainted
Ferrous Metals and Nonmagnetic, Nonconductive Coat-
Sheet
ings Applied to Non-Ferrous Metals
D4146 Test Method for Formability of Zinc-Rich Primer/
D7093 Test Method for Formability of Thin Film Organic
Chromate Complex Coatings on Steel
Coatings on Steel Over a Biaxially Stretched Dome
D4147 Practice for Applying Coil Coatings Using Wire-
D7376 PracticeforOutdoorEvaluationofWetStackStorage
Wound Drawdown Bars
Conditions on Coil-Coated Metals
D4212 Test Method for Viscosity by Dip-Type Viscosity
D7639 Test Method for Determination of Zirconium Treat-
Cups
ment Weight or Thickness on Metal Substrates by X-Ray
D4214 Test Methods for Evaluating the Degree of Chalking
Fluorescence
of Exterior Paint Films
D7835 Test Method for Determining the Solvent Resistance
D4287 Test Method for High-Shear Viscosity Using a Cone/
of an Organic Coating Using a Mechanical Rubbing
Plate Viscometer
Machine
D4518 Test Methods for Measuring Static Friction of Coat-
D7893 Guide for Corrosion Test Panel Preparation, Testing,
and Rating of Coil-Coated Building Products
3 D7869 PracticeforXenonArcExposureTestwithEnhanced
The last approved version of this historical standard is referenced on
www.astm.org. Light and Water Exposure for Transportation Coatings
D3794 − 22
D7897 Practice for Laboratory Soiling and Weathering of 3. Terminology
RoofingMaterialstoSimulateEffectsofNaturalExposure
3.1 Definitions:
on Solar Reflectance and Thermal Emittance
3.1.1 coil coating, n—application of coatings or films to
D8331 Test Method for Measurement of Film Thickness of
continuous metal coil stock.
Thin-Film Coatings by Non-Destructive Means Using
3.1.2 direct roller coat, n—coating with the applicator or
Ruggedized Optical Interference
coating roll revolving in the same direction as the strip.
E70 Test Method for pH of Aqueous Solutions With the
3.1.3 metal pretreatment, n—chemical treatment normally
Glass Electrode
applied to the metal substrate prior to prime or finish coating.
E84 Test Method for Surface Burning Characteristics of
3.1.3.1 Discussion—The treatment is designed to react with
Building Materials
andmodifythemetalsubstratetoproduceasurfacesuitablefor
E284 Terminology of Appearance
coating or adhesive bonding.
E308 PracticeforComputingtheColorsofObjectsbyUsing
3.1.4 reverse roller coat, n—coating with the applicator or
the CIE System
coatingrollrevolvinginadirectionoppositetothatofthestrip.
E376 Practice for Measuring Coating Thickness by
3.2 The definitions given in Terminology G113 are appli-
Magnetic-Field or Eddy Current (Electromagnetic) Test-
cable to this guide.
ing Methods
E408 Test Methods for Total Normal Emittance of Surfaces
4. Significance and Use
Using Inspection-Meter Techniques
4.1 This guide represents a collection of pertinent ASTM
E643 Test Method for Ball Punch Deformation of Metallic
test methods used within the coil coatings industry. In the past
Sheet Material
coilcoatersworldwidedependedonindustrystandardswritten
E903 Test Method for Solar Absorptance, Reflectance, and
by the National Coil Coating Association. That association,
Transmittance of Materials Using Integrating Spheres
working cooperatively with ASTM, will no longer issue new,
E1164 PracticeforObtainingSpectrometricDataforObject-
nor update old, standards.
Color Evaluation
E1356 Test Method for Assignment of the Glass Transition
5. General Requirements
Temperatures by Differential Scanning Calorimetry
5.1 All standard tests shall be made at 25 6 3 °C (77 6
E1541 Practice for Specifying and Matching Color Using
25 °F) and 50 6 5 % relative humidity, immediately after
the Colorcurve System (Withdrawn 2007)
baking unless otherwise specified.
E1545 Test Method for Assignment of the Glass Transition
6. Sampling
Temperature by Thermomechanical Analysis
E1640 Test Method for Assignment of the Glass Transition
6.1 The number of samples per unit of production shall be
Temperature By Dynamic Mechanical Analysis
agreed upon between the producer and user.
E1808 Guide for Designing and Conducting Visual Experi-
7. Liquid Coating Properties
ments
E1918 Test Method for Measuring Solar Reflectance of
7.1 Viscosity:
Horizontal and Low-Sloped Surfaces in the Field 7.1.1 It is common to measure the viscosity of coil coatings
E1980 Practice for Calculating Solar Reflectance Index of using an efflux technique (Ford or Zahn cup). This provides a
simple, rapid technique for controlling the viscosity of a
Horizontal and Low-Sloped Opaque Surfaces
product, either in a paint production facility, or on-line at a coil
G7 Practice for Natural Weathering of Materials
coating facility. Coatings in the coil industry, however, cover a
G60 Practice for Conducting Cyclic Humidity Exposures
wide range of generic qualities, with many of them having
G85 Practice for Modified Salt Spray (Fog) Testing
non-Newtonian rheological characteristics. It is important,
G87 Practice for Conducting Moist SO Tests
therefore, to consider the behavior of these coatings under
G90 Practice for Performing Accelerated Outdoor Weather-
different shear conditions, as well as measuring efflux viscos-
ing of Materials Using Concentrated Natural Sunlight
ity. Some of the test methods require little expertise, where
G113 Terminology Relating to Natural andArtificial Weath-
othertestmethodsinvolvecostlyequipmentandahighlevelof
ering Tests of Nonmetallic Materials
experience to run and interpret the rheological data.
G151 Practice for Exposing Nonmetallic Materials inAccel-
7.1.2 Efflux Viscosity—Determine efflux viscosity in accor-
erated Test Devices that Use Laboratory Light Sources
dance with Test Method D4212 (Zahn cup) or D1200 (Ford
G152 Practice for Operating Open Flame Carbon Arc Light
cup).
Apparatus for Exposure of Nonmetallic Materials
7.1.3 High-Shear Extrusion Viscosity—Determine the high-
G153 Practice for Operating Enclosed Carbon Arc Light
shear extrusion viscosity for plastisols and organosols in
Apparatus for Exposure of Nonmetallic Materials
accordance with Test Method D1823.
G154 Practice for Operating Fluorescent Ultraviolet (UV)
7.1.4 Low-Shear Viscosity for Plastisols and Organosols—
Lamp Apparatus for Exposure of Nonmetallic Materials
Test in accordance with Test Method D1824.
G155 Practice for Operating XenonArc LampApparatus for
7.1.5 Rotational Viscosity—Determine the viscosity with a
Exposure of Materials rotational viscometer in accordance with Test Method D2196.
D3794 − 22
TABLE 1 List of Test Methods and Recommended Practices
Section ASTM Standard
Liquid Coatings Properties: 7
Viscosity: 7.1
Ford cup viscosity 7.1.2 D1200
Zahn cup viscosity 7.1.2 D4212
High-Shear extrusion viscometer 7.1.3 D1823
Plastisol and organosol low-shear viscosity 7.1.4 D1824
Rotational viscometer 7.1.5 D2196
Cone and Plate viscometer 7.1.6 D4287
Weight Solids 7.2 D2369
Volatile Content 7.2 D2369
Volume Solids 7.3 D2697, D6093
Fineness of dispersion 7.4 D1210
Density (weight per gallon) 7.5 D1475
VOC Determination 7.6 D3960
pH 7.7 E70
Flash Point 7.8 D3278
Metal Pretreatment: 8
Preparation of galvanized steel for painting 8.2 D2092
Detecting Cr+6 8.3.1 D6492
X-ray fluorescence, chrome determination 8.3.2 D5723
X-ray fluorescence, titanium determination 8.3.3 D6906
X-ray fluorescence, zirconium determination 8.3.4 D7639
Panel Preparation: 9
Wire-wound drawdown bars 9.4.1.1 D4147
Blade film applicator 9.4.1.2 D823
Wet film thickness 9.5 D1212
Material Properties of a Cured Coil Coating System: 10
Dry film thickness (DFT) 10.1
DFT, destructive methods 10.1.1
DFT, micrometer 10.1.1.1 D1005
DFT, microscope 10.1.1.2 D4138
DFT, boring method 10.1.1.3 D5796
DFT, non-destructive methods 10.1.2
DFT, eddy current, non-ferrous base 10.1.2.1 D7091, E376
DFT, magnetic flux, ferrous base 10.1.2.2 D7091, E376
DFT, ruggedized optical interference 10.1.2.3 D8331
Color: 10.2
Glossary of color 10.2.1 E284
Preparation and control of color standards 10.2.1 D5531
Color and gloss tolerances 10.2.1 D3134
Conducting visual experiments 10.2.1 E1808
Color differences by visual evaluation 10.2.2
Visual evaluation of color and color difference 10.2.2.1 D1729
Color differences by instrumental evaluation 10.2.3
Color matching, color curve system 10.2.3 E1541
CIE color difference 10.2.3 E308
Obtaining special data 10.2.3 E1164
Calculation of color differences 10.2.3 D2244
Specular gloss measurement 10.3 D523
Hardness: 10.4
Pencil hardness 10.4.1 D3363
Indentation hardness 10.4.2 D1474
Flexibility: 10.5
Impact resistance 10.5.2 D2794
Mandrel bend 10.5.3 D522
T bends 10.5.4 D4145
Ball punch deformation 10.5.5 E643
Draw test 10.5.6 D4146, D7093
Adhesion: 10.6
Cross hatch tape adhesion 10.6.2 D3359
Scrape adhesion 10.6.3 D2197
Degree of Cure: 10.7
Glass transition, TMA 10.7.2 E1545
Glass transition, DMA 10.7.2 E1640
Glass transition, DSC 10.7.2 E1356
Solvent resistance 10.7.3 D5402
Solvent resistance, mechanical rub machine 10.7.3 D7835
Dry heat test 10.7.4 D6491
Boiling water test 10.7.5 D6665
Other tests: 10.8
Pressure mottling/blocking resistance 10.8.1 D3003
Effect of overbaking 10.8.2 D2454
D3794 − 22
TABLE 1 Continued
Section ASTM Standard
Detergent resistance 10.8.3 D2248
Effect of household chemicals 10.8.4 D1308
Abrasion and mar resistance 10.8.5
Taber abraser 10.8.5.1 D4060
Falling (sand) abrasive 10.8.5.2 D968
Mar resistance 10.8.5.3 D5178
Flame spread 10.8.6 E84
Chip resistance 10.8.7 D3170
Coefficient of friction 10.8.9 D4518
Resistance to thermal cycling 10.8.10 D6944
Graffiti resistance 10.8.11 D6578
Radiative Properties of Cured Coil Coating Systems: 11
Solar Reflectance: 11.1
Measuring solar reflectance of horizontal and low-slope surfaces in the field 11.1.1.1 E1918
Measuring solar reflectance in laboratory and field 11.1.1.2 C1549
Method for solar absorbance, reflectance, and transmittance 11.1.1.3 E903
Practice for calculating solar reflectance index of horizontal and low-sloped opaque 11.1.1.4 E1980
surfaces
Laboratory soiling test to simulate natural exposure 11.1.1.5 D7897
Thermal emittance: 11.2
Measuring hemispherical emittance 11.2.1.1 C1371
Measuring total normal emittance 11.2.1.2 E408
Weathering and Corrosion Resistance Properties of a Cured Coil Coating System: 12
Real-time weathering: 12.1
Conducting exterior weathering tests 12.1.1 D1014, D7893, G7
Chalk resistance 12.1.2.2 D4214
Degree of rusting 12.1.2.5 D610
Degree of blistering: 12.1.2.1 D714
Checking 12.1.2.3 D660
Cracking 12.1.2.4 D661
Corrosion creepage 12.1.2.6 D1654
Wet storage resistance 12.1.3.1 D7376
Accelerated corrosion and environmental resistance characteristics: 12.2
Salt spray 12.2.1 B117
Water fog 12.2.2 D1735
100 % Relative humidity 12.2.2 D2247
Condensation humidity 12.2.3 D4585
Water immersion 12.2.4 D870
Cyclic salt spray 12.2.5 G85
Cyclic salt fog/UV condensation: 12.2.5 D5894
Cyclic humidity 12.2.5 G60
Moist SO testing (Kesternich) 12.2.6 G87
Copper-accelerated salt spray (CASS) 12.2.7 B368
Filiform corrosion 12.2.8 D2803
Specification for reagent water 12.2.9 D1193
Accelerated weathering tests: 12.3
Dew cycle (Unfiltered open-flame carbon arc) 12.3.2 D3361, G151
Filtered, open-flame carbon arc 12.3.3 D822, G151, G152
Fluorescent UV-condensation 12.3.4 D4587, G151, G154
Enclosed carbon arc 12.3.5 D5031, G153, G151
Xenon arc 12.3.6 G151, G155, D6695, D7869
Accelerated outdoor tests (black box, heated black box, Fresnel) 12.3.7 D4141, G90
7.1.6 Cone and Plate Viscometer—Determine the viscosity 7.7 pH—Controllingthelevelofacidityoralkalinity(pH)in
using a cone and plate viscometer in accordance with Test the pretreatment section of a coil line, as well as that of
Method D4287. waterbornecoatings,isimportant.DeterminepHinaccordance
with Test Method E70.
7.2 Weight Solids—Determine the level of nonvolatile mass
in accordance with Test Method D2369. 7.8 Flash Point—Test the flash point of a coating in accor-
dance with Test Methods D3278.
7.3 Volume Solids—Determine the level of nonvolatile vol-
ume in accordance with Test Method D2697 or D6093.
8. Metal Pretreatment
7.4 Fineness of Dispersion—Determine the fineness of
8.1 Thesuccessfulperformanceofanycoil-coatedsystemis
grind of a coating in accordance with Test Method D1210.
dependent on metal substrate preparation. Metal preparation in
7.5 Density—Determine the density (weight per gallon) in
the coil coating industry usually consists of one of the
accordance with Test Method D1475.
followingmethodologies:clean,rinse,formationofconversion
7.6 VOC—Determine the VOC (volatile organic compo- coating, rinse, post-treatment of conversion coating, and dry;
nent) content in accordance with Practice D3960. or, clean, rinse, application of a roll-on pretreatment, and dry.
D3794 − 22
The metal pretreatment promotes maximum formability and 9.4.1.1 Drawdown Bars—Prepare drawdowns in accor-
adhesion of the organic coatings to the substrate, as well as dance with Practice D4147.
promoting environmental exposure resistance, including anti- 9.4.1.2 Blade Film Applicator—Prepare samples (at film
corrosive properties, of the coil coated system. Cleaners, thicknesses greater than >38 µ (>1.5 mils) in accordance with
conversion coating treatments, dried-in-place roll-on Practices D823.
pretreatments, and post-treatments vary with the performance
9.5 Wet Film Thickness—Determine the wet thickness of an
desired, the coating system used, and the metal substrate.
applied coating in accordance with Test Methods D1212.
Because there is an interdependency between the cleaning,
9.6 Bake Schedule—Bake the panel at a time and tempera-
pretreating, and post-treatment steps, in order to obtain accept-
ture to meet a metal temperature range agreed upon between
able performance, it is necessary that the reaction times,
the producer and user. The critical parameter in this baking
concentrations, temperatures, and application methods used in
process is the “peak metal temperature.”This term refers to the
the laboratory be as close as possible to those encountered
maximumtemperaturethatthesubstratehasreachedduringthe
under production condition, and that both laboratory and
baking cycle. In addition to peak metal temperature, other
production conditions be in strict accordance with the pretreat-
baking conditions, which influence the long-term performance
ment suppliers’ specifications.
of a coil coating, are the oven air temperature, and the time in
8.2 In the case of zinc coated steel surfaces, Guide D2092,
which the coated metal is exposed to the heat within the oven
Methods A, B, C, D, and F illustrate the variety of pretreat-
(also called “dwell time”).The peak metal temperature may be
ments available.
measured using infrared thermometry or a thermocouple, but
the most common method is to utilize “temperature tapes.”
8.3 Coating Weight of Metal Pretreatment—The one param-
These self-adhesive strips contain temperature-sensitive indi-
etertoensurethatasubstrateisproperlycleanedandpretreated
cators covering a range of temperatures.
is the measurement of the level of pretreatment and post-
treatment.
10. Physical Properties of Cured Coil Coating System
8.3.1 Determine the presence of hexavalent chromium on
zinc and zinc/aluminum alloy coated steel in accordance with 10.1 Dry Film Thickness (DFT)—Thereareseveralmethods
used for determining the dry film thickness of a coil coating.
Practice D6492.
The ability to measure the dry film thickness accurately is of
8.3.2 X-ray Fluorescence—Determine the chromium weight
utmost importance when one considers that the typical coil
in accordance with Practice D5723.
coating system (primer+topcoat) is often no more than 25-µ
8.3.3 X-ray Fluorescence—Determine the titanium weight
(1-mil) thick. It is always advisable to take at least three DFT
in accordance with Test Method D6906.
measurements to obtain an average value of DFT. There are
8.3.4 X-ray Fluorescence—Determine the zirconium weight
both non-destructive and destructive means of measuring film
or thickness with Test Method D7639.
thickness for ferrous or aluminum substrates. Coatings applied
to commercially available hot-dipped galvanized steel, zinc-
9. Panel Preparation
aluminum,andothernonferrousalloys,mayonlybemeasured,
9.1 Summary of Method—This method includes substrate
due to the uneven nature of the alloy layer, by destructive
and pretreatment selection for application of coatings by wire
means.
wound draw-down bars on laboratory panels.
10.1.1 Destructive Determination of Dry Film Thickness:
10.1.1.1 Micrometer—Determine the DFT of a coil coating
9.2 Choice of Substrate—The substrate to be coated, sub-
withamicrometerinaccordancewithTestMethodD1005.The
strate size, gage, temper, alloy, and pretreatment to be used
micrometer must be capable of reading to ≤0.0005 in.
shall be agreed upon between the producer and user. Avoid
(0.05 mils).
using substrates that have been contaminated by handling.
10.1.1.2 Microscope (Tooke Gage)—Determine the DFT of
9.3 Degassing of Substrate—Some galvanized substrates
a coil coating with a microscope in accordance with Test
tend to absorb gasses on aging. To avoid blistering when the
Method D4138.
substrate is coated and baked it may be necessary to de-gas the
10.1.1.3 Boring Method—Determine the DFT of a coil
substrate by heating and cooling to room temperature prior to
coating with a boring device in accordance with Test Method
application of the coating. The time and temperature of the
D5796.
degassingcycleshallbeagreeduponbetweentheproducerand
10.1.2 Non-Destructive Determination of Dry Film Thick-
user.
ness:
9.4 Drawdowns, Apparatus: 10.1.2.1 Eddy-Current—Determine the DFT of a coil coat-
9.4.1 Stainless Steel Wire-wound Draw-down Bars, (prefer- ing on aluminum in accordance with Test Method D7091 and
ably 12.7 mm ( ⁄2 in. in diameter to prevent bowing during Practice E376.
application) are used to achieve dry film thickness up to 38 µ 10.1.2.2 Magnetic Flux—Determine the DFT of a coil
(1.5 mils). The choice of the specific drawdown bar is coating on a ferrous substrate in accordance with Test Method
dependent on the dry film thickness required, the rheological D7091 and Practice E376.
properties of the coating, and the volume solids of the coating 10.1.2.3 Ruggedized Optical Interference—Determine the
being tested. Other methods of applying thicker coating >38 µ film thickness over any metal substrate in accordance withTest
(>1.5 mils) are available, such as a blade applicator. Method D8331.
D3794 − 22
10.2 Color: “darkness” quality when used on white paper (since they are
10.2.1 The color difference between two homogeneously actuallydraftingpencils).Themanufacturersdonotcontrolthe
colored opaque films may be determined by visual evaluation pencils for any engineering properties that are associated with
or by instrumental means. The color standard used shall be the strength of material (a coil coating
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3794 − 18 D3794 − 22
Standard Guide for
Testing Coil Coatings
This standard is issued under the fixed designation D3794; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This guide covers procedures for testing coil coatings. The test methods included are listed in Table 1. Where more than one
test method is listed for the same characteristic, no attempt is made to indicate superiority of one method over another. Selection
of test methods to be followed must be governed by the requirements in each individual case, together with agreement between
the producer and user.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
B117 Practice for Operating Salt Spray (Fog) Apparatus
B368 Test Method for Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing (CASS Test)
C1371 Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers
C1549 Test Method for Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer
D522 Test Methods for Mandrel Bend Test of Attached Organic Coatings
D523 Test Method for Specular Gloss
D610 Practice for Evaluating Degree of Rusting on Painted Steel Surfaces
D660 Test Method for Evaluating Degree of Checking of Exterior Paints
D661 Test Method for Evaluating Degree of Cracking of Exterior Paints
D714 Test Method for Evaluating Degree of Blistering of Paints
D822 Practice for Filtered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
D823 Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels
D870 Practice for Testing Water Resistance of Coatings Using Water Immersion
D968 Test Methods for Abrasion Resistance of Organic Coatings by Falling Abrasive
D1005 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
This guide is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of Subcommittee
D01.53 on Coil Coated Metal.
Current edition approved June 1, 2018June 15, 2022. Published June 2018July 2022. Originally approved in 1979. Last previous edition approved in 20172018 as
D3794 – 17.D3794 – 18. DOI: 10.1520/D3794-18.10.1520/D3794-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3794 − 22
D1014 Practice for Conducting Exterior Exposure Tests of Paints and Coatings on Metal Substrates
D1193 Specification for Reagent Water
D1200 Test Method for Viscosity by Ford Viscosity Cup
D1210 Test Method for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-Type Gage
D1212 Test Methods for Measurement of Wet Film Thickness of Organic Coatings
D1308 Test Method for Effect of Household Chemicals on Clear and Pigmented Coating Systems
D1474 Test Methods for Indentation Hardness of Organic Coatings
D1475 Test Method for Density of Liquid Coatings, Inks, and Related Products
D1654 Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments
D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
D1735 Practice for Testing Water Resistance of Coatings Using Water Fog Apparatus
D1823 Test Method for Apparent Viscosity of Plastisols and Organosols at High Shear Rates by Extrusion Viscometer
D1824 Test Method for Apparent Viscosity of Plastisols and Organosols at Low Shear Rates
D2092 Guide for Preparation of Zinc-Coated (Galvanized) Steel Surfaces for Painting (Withdrawn 2008)
D2196 Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational Viscometer
D2197 Test Method for Adhesion of Organic Coatings by Scrape Adhesion
D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
D2247 Practice for Testing Water Resistance of Coatings in 100 % Relative Humidity
D2248 Practice for Detergent Resistance of Organic Finishes
D2369 Test Method for Volatile Content of Coatings
D2454 Practice for Determining the Effect of Overbaking on Organic Coatings
D2697 Test Method for Volume Nonvolatile Matter in Clear or Pigmented Coatings
D2794 Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact)
D2803 Guide for Testing Filiform Corrosion Resistance of Organic Coatings on Metal
D3003 Test Method for Pressure Mottling and Blocking Resistance of Organic Coatings on Metal Substrates
D3134 Practice for Establishing Color and Gloss Tolerances
D3170 Test Method for Chipping Resistance of Coatings
D3278 Test Methods for Flash Point of Liquids by Small Scale Closed-Cup Apparatus
D3359 Test Methods for Rating Adhesion by Tape Test
D3361 Practice for Unfiltered Open-Flame Carbon-Arc Exposures of Paint and Related Coatings
D3363 Test Method for Film Hardness by Pencil Test
D3960 Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings
D4060 Test Method for Abrasion Resistance of Organic Coatings by the Taber Abraser
D4138 Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-Sectioning
Means
D4141 Practice for Conducting Black Box and Solar Concentrating Exposures of Coatings
D4145 Test Method for Coating Flexibility of Prepainted Sheet
D4146 Test Method for Formability of Zinc-Rich Primer/Chromate Complex Coatings on Steel
D4147 Practice for Applying Coil Coatings Using Wire-Wound Drawdown Bars
D4212 Test Method for Viscosity by Dip-Type Viscosity Cups
D4214 Test Methods for Evaluating the Degree of Chalking of Exterior Paint Films
D4287 Test Method for High-Shear Viscosity Using a Cone/Plate Viscometer
D4518 Test Methods for Measuring Static Friction of Coating Surfaces (Withdrawn 2000)
D4585 Practice for Testing Water Resistance of Coatings Using Controlled Condensation
D4587 Practice for Fluorescent UV-Condensation Exposures of Paint and Related Coatings
D5031 Practice for Enclosed Carbon-Arc Exposure Tests of Paint and Related Coatings
D5178 Test Method for Mar Resistance of Organic Coatings
D5402 Practice for Assessing the Solvent Resistance of Organic Coatings Using Solvent Rubs
D5531 Guide for Preparation, Maintenance, and Distribution of Physical Product Standards for Color and Geometric
Appearance of Coatings
D5723 Practice for Determination of Chromium Treatment Weight on Metal Substrates by X-Ray Fluorescence
D5796 Test Method for Measurement of Dry Film Thickness of Thin-Film Coil-Coated Systems by Destructive Means Using
a Boring Device
D5894 Practice for Cyclic Salt Fog/UV Exposure of Painted Metal, (Alternating Exposures in a Fog/Dry Cabinet and a
UV/Condensation Cabinet)
D6093 Test Method for Percent Volume Nonvolatile Matter in Clear or Pigmented Coatings Using a Helium Gas Pycnometer
The last approved version of this historical standard is referenced on www.astm.org.
D3794 − 22
D6491 Practice for Evaluation of Aging Resistance of Prestressed Prepainted Metal In a Dry Heat Test
D6492 Practice for Detection of Hexavalent Chromium On Zinc and Zinc/Aluminum Alloy Coated Steel
D6578 Practice for Determination of Graffiti Resistance
D6665 Practice for Evaluation of Aging Resistance of Pre-stressed Prepainted Metal in a Boiling Water Test
D6695 Practice for Xenon-Arc Exposures of Paint and Related Coatings
D6906 Test Method for Determination of Titanium Treatment Weight on Metal Substrates by Wavelength Dispersive X-Ray
Fluorescence
D6944 Practice for Determining the Resistance of Cured Coatings to Thermal Cycling
D7091 Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals
and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals
D7093 Test Method for Formability of Thin Film Organic Coatings on Steel Over a Biaxially Stretched Dome
D7376 Practice for Outdoor Evaluation of Wet Stack Storage Conditions on Coil-Coated Metals
D7639 Test Method for Determination of Zirconium Treatment Weight or Thickness on Metal Substrates by X-Ray Fluorescence
D7835 Test Method for Determining the Solvent Resistance of an Organic Coating Using a Mechanical Rubbing Machine
D7893 Guide for Corrosion Test Panel Preparation, Testing, and Rating of Coil-Coated Building Products
D7869 Practice for Xenon Arc Exposure Test with Enhanced Light and Water Exposure for Transportation Coatings
D7897 Practice for Laboratory Soiling and Weathering of Roofing Materials to Simulate Effects of Natural Exposure on Solar
Reflectance and Thermal Emittance
D8331 Test Method for Measurement of Film Thickness of Thin-Film Coatings by Non-Destructive Means Using Ruggedized
Optical Interference
E70 Test Method for pH of Aqueous Solutions With the Glass Electrode
E84 Test Method for Surface Burning Characteristics of Building Materials
E284 Terminology of Appearance
E308 Practice for Computing the Colors of Objects by Using the CIE System
E376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy Current (Electromagnetic) Testing Methods
E408 Test Methods for Total Normal Emittance of Surfaces Using Inspection-Meter Techniques
E643 Test Method for Ball Punch Deformation of Metallic Sheet Material
E903 Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres
E1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation
E1356 Test Method for Assignment of the Glass Transition Temperatures by Differential Scanning Calorimetry
E1541 Practice for Specifying and Matching Color Using the Colorcurve System (Withdrawn 2007)
E1545 Test Method for Assignment of the Glass Transition Temperature by Thermomechanical Analysis
E1640 Test Method for Assignment of the Glass Transition Temperature By Dynamic Mechanical Analysis
E1808 Guide for Designing and Conducting Visual Experiments
E1918 Test Method for Measuring Solar Reflectance of Horizontal and Low-Sloped Surfaces in the Field
E1980 Practice for Calculating Solar Reflectance Index of Horizontal and Low-Sloped Opaque Surfaces
G7 Practice for Natural Weathering of Materials
G60 Practice for Conducting Cyclic Humidity Exposures
G85 Practice for Modified Salt Spray (Fog) Testing
G87 Practice for Conducting Moist SO Tests
G90 Practice for Performing Accelerated Outdoor Weathering of Materials Using Concentrated Natural Sunlight
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G152 Practice for Operating Open Flame Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
G153 Practice for Operating Enclosed Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
G154 Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials
G155 Practice for Operating Xenon Arc Lamp Apparatus for Exposure of Materials
3. Terminology
3.1 Definitions:
3.1.1 coil coating, n—application of coatings or films to continuous metal coil stock.
3.1.2 direct roller coat, n—coating with the applicator or coating roll revolving in the same direction as the strip.
3.1.3 metal pretreatment, n—chemical treatment normally applied to the metal substrate prior to prime or finish coating.
D3794 − 22
3.1.3.1 Discussion—
The treatment is designed to react with and modify the metal substrate to produce a surface suitable for coating or adhesive
bonding.
3.1.4 reverse roller coat, n—coating with the applicator or coating roll revolving in a direction opposite to that of the strip.
3.2 The definitions given in Terminology G113 are applicable to this guide.
4. Significance and Use
4.1 This guide represents a collection of pertinent ASTM test methods used within the coil coatings industry. In the past coil
coaters world wide depended on industry standards written by the National Coil Coating Association. That association, working
cooperatively with ASTM, will no longer issue new, nor update old, standards.
5. General Requirements
5.1 All standard tests shall be made at 25 6 3°C3 °C (77 6 25°F)25 °F) and 50 6 5 % relative humidity, immediately after baking
unless otherwise specified.
6. Sampling
6.1 The number of samples per unit of production shall be agreed upon between the producer and user.
7. Liquid Coating Properties
7.1 Viscosity:
7.1.1 It is common to measure the viscosity of coil coatings using an efflux technique (Ford or Zahn cup). This provides a simple,
rapid technique for controlling the viscosity of a product, either in a paint production facility, or on-line at a coil coating facility.
Coatings in the coil industry, however, cover a wide range of generic qualities, with many of them having non-Newtonian
rheological characteristics. It is important, therefore, to consider the behavior of these coatings under different shear conditions,
as well as measuring efflux viscosity. Some of the test methods require little expertise, where other test methods involve costly
equipment and a high level of experience to run and interpret the rheological data.
7.1.2 Efflux Viscosity—Determine efflux viscosity in accordance with Test Method D4212 (Zahn cup) or D1200 (Ford cup).
7.1.3 High-Shear Extrusion Viscosity—Determine the high-shear extrusion viscosity for plastisols and organosols in accordance
with Test Method D1823.
7.1.4 Low-Shear Viscosity for Plastisols and Organosols—Test in accordance with Test Method D1824.
7.1.5 Rotational Viscosity—Determine the viscosity with a rotational viscometer in accordance with Test Method D2196.
7.1.6 Cone and Plate Viscometer—Determine the viscosity using a cone and plate viscometer in accordance with Test Method
D4287.
7.2 Weight Solids—Determine the level of nonvolatile mass in accordance with Test Method D2369.
7.3 Volume Solids—Determine the level of nonvolatile volume in accordance with Test Method D2697 or D6093.
7.4 Fineness of Dispersion—Determine the fineness of grind of a coating in accordance with Test Method D1210.
7.5 Density—Determine the density (weight per gallon) in accordance with Test Method D1475.
7.6 VOC—Determine the VOC (volatile organic component) content in accordance with Practice D3960.
D3794 − 22
TABLE 1 List of Test Methods and Recommended Practices
Section ASTM Standard
Liquid Coatings Properties: 7
Viscosity: 7.1
Ford cup viscosity 7.1.2 D1200
Zahn cup viscosity 7.1.2 D4212
High-Shear extrusion viscometer 7.1.3 D1823
Plastisol and organosol low-shear viscosity 7.1.4 D1824
Rotational viscometer 7.1.5 D2196
Cone and Plate viscometer 7.1.6 D4287
Weight Solids 7.2 D2369
Volatile Content 7.2 D2369
Volume Solids 7.3 D2697, D6093
Fineness of dispersion 7.4 D1210
Density (weight per gallon) 7.5 D1475
VOC Determination 7.6 D3960
pH 7.7 E70
Flash Point 7.8 D3278
Metal Pretreatment: 8
Preparation of galvanized steel for painting 8.2 D2092
Detecting Cr+6 8.3.1 D6492
X-ray fluorescence, chrome determination 8.3.2 D5723
X-ray fluorescence, titanium determination 8.3.3 D6906
X-ray fluorescence, zirconium determination 8.3.4 D7639
Panel Preparation: 9
Wire-wound drawdown bars 9.4.1.1 D4147
Blade film applicator 9.4.1.2 D823
Wet film thickness 9.5 D1212
Material Properties of a Cured Coil Coating System: 10
Dry film thickness (DFT) 10.1
DFT, destructive methods 10.1.1
DFT, micrometer 10.1.1.1 D1005
DFT, microscope 10.1.1.2 D4138
DFT, boring method 10.1.1.3 D5796
DFT, non-destructive methods 10.1.2
DFT, eddy current, non-ferrous base 10.1.2.1 D7091, E376
DFT, magnetic flux, ferrous base 10.1.2.2 D7091, E376
DFT, ruggedized optical interference 10.1.2.3 D8331
Color: 10.2
Glossary of color 10.2.1 E284
Preparation and control of color standards 10.2.1 D5531
Color and gloss tolerances 10.2.1 D3134
Conducting visual experiments 10.2.1 E1808
Color differences by visual evaluation 10.2.2
Visual evaluation of color and color difference 10.2.2.1 D1729
Color differences by instrumental evaluation 10.2.3
Color matching, color curve system 10.2.3 E1541
CIE color difference 10.2.3 E308
Obtaining special data 10.2.3 E1164
Calculation of color differences 10.2.3 D2244
Specular gloss measurement 10.3 D523
Hardness: 10.4
Pencil hardness 10.4.1 D3363
Indentation hardness 10.4.2 D1474
Flexibility: 10.5
Impact resistance 10.5.2 D2794
Mandrel bend 10.5.3 D522
T bends 10.5.4 D4145
Ball punch deformation 10.5.5 E643
Draw test 10.5.6 D4146, D7093
Adhesion: 10.6
Cross hatch tape adhesion 10.6.2 D3359
Scrape adhesion 10.6.3 D2197
Degree of Cure: 10.7
Glass transition, TMA 10.7.2 E1545
Glass transition, DMA 10.7.2 E1640
Glass transition, DSC 10.7.2 E1356
Solvent resistance 10.7.3 D5402
Solvent resistance, mechanical rub machine 10.7.3 D7835
Dry heat test 10.7.4 D6491
Boiling water test 10.7.5 D6665
Other tests: 10.8
Pressure mottling/blocking resistance 10.8.1 D3003
Effect of overbaking 10.8.2 D2454
D3794 − 22
TABLE 1 Continued
Section ASTM Standard
Detergent resistance 10.8.3 D2248
Effect of household chemicals 10.8.4 D1308
Abrasion and mar resistance 10.8.5
Taber abraser 10.8.5.1 D4060
Falling (sand) abrasive 10.8.5.2 D968
Mar resistance 10.8.5.3 D5178
Flame spread 10.8.6 E84
Chip resistance 10.8.7 D3170
Coefficient of friction 10.8.9 D4518
Resistance to thermal cycling 10.8.10 D6944
Graffiti resistance 10.8.11 D6578
Radiative Properties of Cured Coil Coating Systems: 11
Solar Reflectance: 11.1
Measuring solar reflectance of horizontal and low-slope surfaces in the field 11.1.1.1 E1918
Measuring solar reflectance in laboratory and field 11.1.1.2 C1549
Method for solar absorbance, reflectance, and transmittance 11.1.1.3 E903
Practice for calculating solar reflectance index of horizontal and low-sloped opaque 11.1.1.4 E1980
surfaces
Laboratory soiling test to simulate natural exposure 11.1.1.5 D7897
Thermal emittance: 11.2
Measuring hemispherical emittance 11.2.1.1 C1371
Measuring total normal emittance 11.2.1.2 E408
Weathering and Corrosion Resistance Properties of a Cured Coil Coating System: 12
Real-time weathering: 12.1
Conducting exterior weathering tests 12.1.1 D1014, D7893, G7
Chalk resistance 12.1.2.2 D4214
Degree of rusting 12.1.2.5 D610
Degree of blistering: 12.1.2.1 D714
Checking 12.1.2.3 D660
Cracking 12.1.2.4 D661
Corrosion creepage 12.1.2.6 D1654
Wet storage resistance 12.1.3.1 D7376
Accelerated corrosion and environmental resistance characteristics: 12.2
Salt spray 12.2.1 B117
Water fog 12.2.2 D1735
100 % Relative humidity 12.2.2 D2247
Condensation humidity 12.2.3 D4585
Water immersion 12.2.4 D870
Cyclic salt spray 12.2.5 G85
Cyclic salt fog/UV condensation: 12.2.5 D5894
Cyclic humidity 12.2.5 G60
Moist SO testing (Kesternich) 12.2.6 G87
Copper-accelerated salt spray (CASS) 12.2.7 B368
Filiform corrosion 12.2.8 D2803
Specification for reagent water 12.2.9 D1193
Accelerated weathering tests: 12.3
Dew cycle (Unfiltered open-flame carbon arc) 12.3.2 D3361, G151
Filtered, open-flame carbon arc 12.3.3 D822, G151, G152
Fluorescent UV-condensation 12.3.4 D4587, G151, G154
Enclosed carbon arc 12.3.5 D5031, G153, G151
Xenon arc 12.3.6 G151, G155, D6695, D7869
Accelerated outdoor tests (black box, heated black box, Fresnel) 12.3.7 D4141, G90
7.7 pH—Controlling the level of acidity or alkalinity (pH) in the pretreatment section of a coil line, as well as that of waterborne
coatings, is important. Determine pH in accordance with Test Method E70.
7.8 Flash Point—Test the flash point of a coating in accordance with Test Methods D3278.
8. Metal Pretreatment
8.1 The successful performance of any coil-coated system is dependent on metal substrate preparation. Metal preparation in the
coil coating industry usually consists of one of the following methodologies: clean, rinse, formation of conversion coating, rinse,
post-treatment of conversion coating, and dry; or, clean, rinse, application of a roll-on pretreatment, and dry. The metal
pretreatment promotes maximum formability and adhesion of the organic coatings to the substrate, as well as promoting
environmental exposure resistance, including anti-corrosive properties, of the coil coated system. Cleaners, conversion coating
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treatments, dried-in-place roll-on pretreatments, and post-treatments vary with the performance desired, the coating system used,
and the metal substrate. Because there is an interdependency between the cleaning, pretreating, and post-treatment steps, in order
to obtain acceptable performance, it is necessary that the reaction times, concentrations, temperatures, and application methods
used in the laboratory be as close as possible to those encountered under production condition, and that both laboratory and
production conditions be in strict accordance with the pretreatment suppliers’ specifications.
8.2 In the case of zinc coated steel surfaces, Guide D2092, Methods A, B, C, D, and F illustrate the variety of pretreatments
available.
8.3 Coating Weight of Metal Pretreatment—The one parameter to ensure that a substrate is properly cleaned and pretreated is the
measurement of the level of pretreatment and post-treatment.
8.3.1 Determine the presence of hexavalent chromium on zinc and zinc/aluminum alloy coated steel in accordance with Practice
D6492.
8.3.2 X-ray Fluorescence—Determine the chromium weight in accordance with Practice D5723.
8.3.3 X-ray Fluorescence—Determine the titanium weight in accordance with Test Method D6906.
8.3.4 X-ray Fluorescence—Determine the zirconium weight or thickness with Test Method D7639.
9. Panel Preparation
9.1 Summary of Method—This method includes substrate and pretreatment selection for application of coatings by wire wound
draw-down bars on laboratory panels.
9.2 Choice of Substrate—The substrate to be coated, substrate size, gage, temper, alloy, and pretreatment to be used shall be agreed
upon between the producer and user. Avoid using substrates that have been contaminated by handling.
9.3 Degassing of Substrate—Some galvanized substrates tend to absorb gasses on aging. To avoid blistering when the substrate
is coated and baked it may be necessary to de-gas the substrate by heating and cooling to room temperature prior to application
of the coating. The time and temperature of the degassing cycle shall be agreed upon between the producer and user.
9.4 Drawdowns, Apparatus:
9.4.1 Stainless Steel Wire-wound Draw-down Bars, (preferably 12.7 mm ( ⁄2 in. in diameter to prevent bowing during application)
are used to achieve dry film thickness up to 38 μ (1.5 mils). The choice of the specific drawdown bar is dependent on the dry film
thickness required, the rheological properties of the coating, and the volume solids of the coating being tested. Other methods of
applying thicker coating >38 μ (>1.5 mils) are available, such as a blade applicator.
9.4.1.1 Drawdown Bars—Prepare drawdowns in accordance with Practice D4147.
9.4.1.2 Blade Film Applicator—Prepare samples (at film thicknesses greater than >38 μ (>1.5 mils) in accordance with Practices
D823.
9.5 Wet Film Thickness—Determine the wet thickness of an applied coating in accordance with Test Methods D1212.
9.6 Bake Schedule—Bake the panel at a time and temperature to meet a metal temperature range agreed upon between the producer
and user. The critical parameter in this baking process is the “peak metal temperature.” This term refers to the maximum
temperature that the substrate has reached during the baking cycle. In addition to peak metal temperature, other baking conditions,
which influence the long-term performance of a coil coating, are the oven air temperature, and the time in which the coated metal
is exposed to the heat within the oven (also called “dwell time”). The peak metal temperature may be measured using infrared
thermometry or a thermocouple, but the most common method is to utilize “temperature tapes.” These self-adhesive strips contain
temperature-sensitive indicators covering a range of temperatures.
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10. Physical Properties of Cured Coil Coating System
10.1 Dry Film Thickness (DFT)—There are several methods used for determining the dry film thickness of a coil coating. The
ability to measure the dry film thickness accurately is of utmost importance when one considers that the typical coil coating system
(primer+topcoat) is often no more than 25-μ (1-mil) thick. It is always advisable to take at least three DFT measurements to obtain
an average value of DFT. There are both non-destructive and destructive means of measuring film thickness for ferrous andor
aluminum substrates. Coatings applied to commercially available hot-dipped galvanized steel, zinc-aluminum, and other
nonferrous alloys, may only be measured, due to the uneven nature of the alloy layer, by destructive means.
10.1.1 Destructive Determination of Dry Film Thickness:
10.1.1.1 Micrometer—Determine the DFT of a coil coating with a micrometer in accordance with Test Method D1005. The
micrometer must be capable of reading to ≤0.0005 in. (0.05 mils).≤0.0005 in. (0.05 mils).
10.1.1.2 Microscope (Tooke Gage)—Determine the DFT of a coil coating with a microscope in accordance with Test Method
D4138.
10.1.1.3 Boring Method—Determine the DFT of a coil coating with a boring device in accordance with Test Method D5796.
10.1.2 Non-Destructive Determination of Dry Film Thickness:
10.1.2.1 Eddy-Current—Determine the DFT of a coil coating on aluminum in accordance with Test Method D7091 and Practice
E376.
10.1.2.2 Magnetic Flux—Determine the DFT of a coil coating on a ferrous substrate in accordance with Test Method D7091 and
Practice E376.
10.1.2.3 Ruggedized Optical Interference—Determine the film thickness over any metal substrate in accordance with Test Method
D8331.
10.2 Color:
10.2.1 The color difference between two homogeneously colored opaque films may be determined by visual evaluation or by
instrumental means. The color standard used shall be agreed upon between the producer and user. Terminology E284 provides a
glossary of terms relating to the field of color. It is common to compare a color sample to a standard. Guide D5531 desc
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