Water-Borne Epoxy Primer
PAINT SPECIFICATION NO. 28 – Water-Borne Epoxy Primer for Steel Surfaces
1.1 This speciﬁcation covers an ambient temperature curing, two-component water-borne epoxy coating for steel that is intended for use as a primer of a multicoat water-borne epoxy or other coating system.
1.2 Primer coatings are categorized according to performance levels (Sections 2.3, 6, and 7).
1.3 Properly topcoated primers meeting this speciﬁcation are suitable for exposures in Environmental Zones 1A (interior, normally dry), 1B (exterior, normally dry), 2A (frequently wet by fresh water), 2B (frequently wet by salt water) and 3C (chemical exposure, alkaline).
1.4 The speciﬁed primer is intended for application by brush, spray, or roller over steel surfaces prepared in accordance with the manufacturer’s recommendations. It is suitable as a shop primer, ﬁeld primer, maintenance primer, or intermediate coat and is to be applied in accordance with SSPC-PA 1. Manufacturer’s recommendations should be followed when the primed steel is to be weathered prior to topcoating.
2.1.1 The primer speciﬁed is typically based on a reactive oxirane (epoxy) functional resin with amine or acid functional curing agents (see Section 4.1).
2.1.2 The major volatile component by weight is water. Refer to ASTM D 3792 or ASTM D 4017 for determining water content of paints.
2.2 VOC LEVEL: The speciﬁed primer may or may not comply with all air pollution regulations. Consult applicable government regulations to determine maximum allowable volatile organic compounds (VOC) and proper VOC test method for a particular application. Supplier should provide VOC information on the coating as supplied (in the container) and as applied (in the ﬁeld after recommended thinning). See Notes 12.2 and 12.3.
2.3 PERFORMANCE LEVEL: Primers shall be classiﬁed according to the exposure performance achieved as follows based on testing of two coats of primer:
Level 1: Accelerated Testing (Section 6) Level 2: Exterior Exposure (Section 7)
2.3.1 If no performance level is speciﬁed, Level 2 is assumed.
3. Referenced Standards
3.1 The latest issue, revision, or amendment of the referenced standards in effect on the date of invitation to bid shall govern unless otherwise speciﬁed. Standards marked with an asterisk (*) are referenced only in the Notes, which are not requirements of this speciﬁcation.
3.2 If there is a conﬂict between the requirements of any of the cited reference standards and this speciﬁcation, the requirements of this speciﬁcation shall prevail.
3.3 SSPC STANDARDS AND JOINT STANDARDS:
SSPC Guide 13
Guide for the Identiﬁcation and Use of Industrial Coating Material in Computerized Product Databases
Shop, Field, and Maintenance Painting of Steel
Measurement of Dry Coating Thickness with Magnetic Gages
SP 10/NACE No. 2
Near-White Blast Cleaning
Guide and Standard Reference Photographs for Evaluating Degree of Rusting on Painted Steel Surfaces
3.4 ASTM INTERNATIONAL STANDARDS:
A 569 (Withdrawn) Speciﬁcation for Steel, Carbon (0.15 Maximum Percent), Hot-Rolled Sheet and Strip, Commercial Quality
B 117 Practice for Operating Salt Spray (Fog) Apparatus
D 562 Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using a Stormer-type Viscometer
D 609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and Related Coating Products
D 610 Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces
D 714 Test Method for Evaluating Degree of Blistering of Paints
D 1210 Test Methods for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-type Gage
D 1296 Test Method for Odor of Volatile Solvents and Diluents
D 1475 Test Method for Density of Liquid Coatings, Inks, and Related Products
D 1654 Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments
D 1849 Test Method for Package Stability of Paint
D 2243 Test Method for Freeze-Thaw Resistance of Water-Borne Coatings
D 2247 Practice for Testing Water Resistance of Coatings in 100% Relative Humidity
D 2369 Test Method for Volatile Content of Coatings
D 2574 Test Method for Resistance of Emulsion Paints in the Container to Attack by Microorganisms
D 3363 Test Method for Film Hardness by Pencil Test
D 3792 Test Method for Water Content of Water Reducible Paints by Direct Injection into a Gas Chromatograph
D 3924 Speciﬁcation for Standard Environment or Conditioning and Testing Paint, Varnish, Lacquer, and Related Materials
D 3925 Practice for Sampling Liquid Paints and Related Pigmented Coatings
* D 3960 Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings
D 4017 Test Method for Water in Paints and Paint Materials by Karl Fischer Method
D 4417 Test Methods for Field Measurement of Surface Proﬁle of Blast Cleaned Steel
D 4585 Practice for Testing the Water Resistance of Coatings Using Controlled Condensation
G 92 Practice for Characterization of Atmospheric Test Sites
3.5 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD:
Z129.1 Hazardous Industrial Chemicals— Precautionary Labeling
3.6 FEDERAL STANDARD:
•40 CFR 60, Appendix A, Method 24—Determination of Volatile Matter Content, Water Content, Density, Volume Solids, and Weight Solids of Surface Coatings
4.1 The manufacturer is given latitude in the selection of materials and process of manufacture, provided that the paint meets the requirements of this speciﬁcation.
5. Standard Testing Conditions
5.1 The standard testing conditions shall be in accordance with the standard atmosphere in ASTM D 3924, unless indicated otherwise. Standard temperature shall be 73.5 ± 3.5°F (23 ± 2°C) and standard relative humidity 50 ± 5%.
5.2 The standard substrate shall be 1/8 inch (3.2 mm) thick ASTM A 569 hot rolled steel abrasive blasted in accordance with SSPC-SP 10 to a proﬁ le of 2.0 ± 0.5 mils (50 ± 13 micrometers) unless indicated otherwise. Measure blast proﬁle in accordance with ASTM D 4417.
5.3 The standard dry ﬁlm thickness of the primer shall be 2.5 ± 0.5 mils (64 ± 13 micrometers) per coat unless indicated otherwise. Measure dry ﬁlm thickness in accordance with SSPC-PA 2.
6. Laboratory Performance Testing Requirements
6.1 For Level 1, the paint shall meet the requirements of Sections 6.2 through 6.13. For Level 2, the paint shall meet the requirements of Sections 6.2 through 6.13 and Sections 7.1 and 7.2.
6.2 RESISTANCE TO MICROORGANISMS IN CONTAINER: The paint shall be resistant to attack by microorganisms when tested according to ASTM D 2574.
6.3 FREEZE-THAW RESISTANCE: Test each of the components separately in accordance with ASTM D 2243. At the end of three cycles there shall be no gelling or excessive thickening, coagulation, lumps or coarse panicles. The maximum allowable increase or decrease in viscosity shall not exceed 10 Krebs units.
6.4 PACKAGE STABILITY: Perform the following tests in accordance with ASTM D 562. Place each component in closed containers in an oven for one month at 25 ± 2°F (52 ± 1°C). The maximum allowable increase or decrease in viscosity shall not exceed 10 Krebs Units. After brushing out, the ﬁlm shall be free from grains, lumps, or streaks.
6.5 MECHANICAL STABILITY: Test each component separately by ﬁlling a one-quart friction top can three-quarters full and closing the can tightly. Rotate on a jar roller for one week at 120 to 170 rpm. At the end of one week, there shall be no indication of separation, coagulation, excessive thickening or
loss in mechanical stability. The maximum allowable increase or decrease in viscosity shall not exceed ten Krebs Units when tested according to ASTM D 562.
6.6 POT LIFE: The term pot life, as used for solvent-borne or solventless epoxies, generally does not have the same meaning for water-borne epoxies. The usable life of mixed components of water-borne epoxies cannot be determined simply by measuring changes in viscosity.To determine usable pot life of water-borne epoxies, thoroughly mix together both components of the primer to yield one quart of mixed primer. Allow the mixed primer to stand at standard conditions under Section 5.1 for the pot life time speciﬁed by the manufacturer. At the end of this time period, the mixed primer shall show no evidence of gellation and must meet the requirements of Sections 6.7, 6.8, 6.10, 6.11, and 6.13.
6.7 LABORATORY APPLICATION PROPERTIES: Thoroughly mix together both components of the primer. Allow mixed primer to stand for manufacturer’s speciﬁed induction time (if any). Apply (brush, roll, or spray) the primer in accordance with the manufacturer’s recommendations to a vertical steel substrate under the standard conditions speciﬁed in Sections 5.1, 5.2, and 5.3. Allow to dry in a well-ventilated room or chamber free from drafts and dust in diffuse light (not in direct sunlight). There shall be no runs, sags, streaks, ﬂashes, laps, pinholing, eyeing, or cratering.
6.8 ADHESION: Condition a primed panel for seven days at standard temperature and humidity (Section 5.1). Evaluate adhesion in accordance with ASTM D 3359 Method B, “Cross Cut Tape Test” using one mm spacing of cuts. A rating of 5B is required.
6.9 RECOAT TESTS: Apply a second coat following the manufacturer’s recommendations. There shall be no picking-up or rolling-up of the ﬁrst coat during applications. After 24 hours, the ﬁlm shall be smooth and uniform.
6.10 FILM IRREGULARITY: Apply one coat of the primer by the drawdown method to a 4 inch x 8 inch (10 cm x 20 cm) cold-rolled steel panel to produce the standard dry ﬁlm thickness (Section 5.3). Allow to dry for 24 hours in accordance with the standard testing conditions speciﬁ ed in Sections 5.1. Examine the ﬁlm for mud-cracking, alligatoring, or other ﬁlm irregularity; there shall be none.
6.11 RUST AND BLISTER RESISTANCE: Spray apply two coats (allowing 24 hours drying time between coats) to four panels in accordance with the standard testing conditions speciﬁed in Sections 5.1, 5.2, and 5.3. Allow to dry for seven days after application of the second coat. Coat and seal all edges and the back side of each panel with a coating that will provide the necessary protection to these surfaces.
Scribe a two-inch (ﬁve cm) vertical line through the lower middle portion of the primed panels so as to expose the underlying metal before testing. The conditions of making the scribe shall be as described in ASTM D 1654.
6.11.1 SALT SPRAY: Expose duplicate panels in the salt fog cabinet for 600 hours according to ASTM B 117. At the end of 600 hours, immediately examine for rusting and blistering. The rusting shall not exceed 8 according to SSPCVIS 2 or ASTM D 610, and the blistering shall not exceed 8F according to ASTM D 714. After examining the panels for blistering, immediately remove the paint ﬁlm with a suitable organic solvent, for example chlorinated hydrocarbon or other solvent recommended by the paint manufacturer. If scraping of the paint ﬁlm is necessary to remove it, do not use a metal spatula or razor blade. Use a piece of soft wood. Examine the steel substrate. The rusting shall not exceed 8 as judged by SSPC-VIS 2 or ASTM D 610. The rust creep, as judged by the bare panel, shall not exceed 1/8 inch (3.2 mm) from the center of the scribe.
6.11.2 CONDENSATION: Expose the other pair of duplicate panels in a condensing cabinet according to ASTM D 4585 for 500 hours at 100°F (38°C). At the end of 500 hours, immediately examine for rusting and blistering. The rusting shall not exceed 8 according to SSPC-VIS 2 or ASTM D 610, and the blistering shall not exceed 8F according to ASTM D 714. After examining the panels for blistering, immediately remove the paint ﬁlm with a suitable organic solvent. If scraping of the paint ﬁlm is necessary to remove it, do not use a metal spatula or razor blade. Use a piece of soft wood. Examine the steel substrate. The rusting shall not exceed 9 as judged by SSPCVIS 2 or ASTM D 610. The rust creep, as judged by the bare panel, shall not exceed 1/8 inch (3.2 mm) from the center of the scribe.
6.12 FLASH RUST RESISTANCE TEST: Apply one coat of the paint in accordance with the standard testing conditions speciﬁed in Sections 5.1, 5.2, and 5.3 and allow to dry in a horizontal position for 24 hours. At the end of the drying period, examine for ﬂash rusting or rust bleeding. The paint shall show no rust bleed-through. After examining the panel for rust bleed-through, immediately remove the paint ﬁlm with a suitable organic solvent. If scraping of the paint ﬁ lm is necessary to remove it, do not use a metal spatula or razor blade. Use a piece of soft wood. Examine the steel substrate. There shall be no rusting of the steel substrate.
6.13 EARLY WATER RESISTANCE: Apply one coat of the primer in accordance with the standard testing conditions speciﬁed in Sections 5.1, 5.2, and 5.3. After six hours of drying, immerse one half of the panel into distilled water for ﬁve minutes. Remove and allow to condition for ten minutes at standard temperature (Section 5.1). The section exposed to the water shall have the same hardness as the unexposed section when checked with either the ﬁngernail or ASTM D 3363 pencil hardness.
7. Test Fence Performance Requirements
7.1 Triplicate panels shall be prepared as described in Section 6.11 except that the coating thickness shall be 3.5 ±
1.0 mils (89 ± 25 micrometers) as measured by SSPC-PA 2.
7.2 EXTERIOR EXPOSURE: Triplicate test specimens shall be exposed for a minimum of 18 months on a test fence at an industrial or marine exposure site having a minimum annual mean precipitation of 25 inches (635 mm) per year. Other criteria for classifying the environment such as corrosion rate of bare steel or bare zinc (in accordance with ASTM G 92), or mean annual temperature may also be required when agreed to between contracting parties. Each specimen shall meet the following requirements (Note 12.4):
- Minimum rust rating of 9 in accordance with SSPC-VIS 2/ASTM D 610
- Maximum scribe undercutting of 1/16 inch (1.6 mm)
8. Material Quality Assurance
8.1 The manufacturer should measure and record batch testing information that would allow certiﬁcation that a batch meets the necessary standards established by the manufacturer for the primer as tested per Section 6.
8.2 CONDITION IN CONTAINER: Each component as received shall show no evidence of livering, skinning, or hard settling of the pigment. The inside of the container shall not be corroded. The material shall be easily dispersed in the liquid portion by hand stirring to form a smooth, homogeneous paint.
8.3 COLOR: The color shall be as speciﬁed in the procurement documents.
8.4 POT LIFE: Mix the primer as speciﬁed in Section 6.6. Allow the mixed primer to stand at standard conditions (Section 5.1) for the pot life speciﬁed by the manufacturer. At the end of this time period, the mixed primer shall show no evidence of gelation.
8.5 VISCOSITY: The viscosity of the mixed primer shall be determined in accordance with ASTM D 62. Variance shall be within ± 5 Krebs units or equivalent units of another viscometer of the viscosity of the previously qualiﬁed primer. For viscosities lower than 55 KU, a number 4 Ford Cup shall be used in accordance with ASTM D 1200. Variations shall be within ± 5 seconds of the viscosity of the previously qualiﬁ ed paint.
8.6 DENSITY: The density of the mixed primer shall be determined in accordance with ASTM D 1475. Variance shall be within ± 0.4 pounds per gallon (50 g/L) of the nominal density of the previously qualiﬁed primer.
8.7 SOLIDS BY WEIGHT: Solids by weight of the mixed primer shall be determined in accordance with ASTM D 2369. Variance shall be within ± 2% of the nominal percent solids by weight of the previously qualiﬁed primer (Note 12.5).
9.1 Labeling shall conform to ANSI Z129.1.
9.2 Technical data shall be provided for at least all data elements categorized as “essential” in SSPC-Guide 13.
9.3 MARKING OF CONTAINERS: Each container of each component shall be legibly marked with the following information:
Name: Water-Borne Epoxy Primer
Speciﬁcation: SSPC-Paint 28
Date of Manufacture:
Quantity of Paint in Container:
Information and Warnings as may be required by
Federal and State Laws:
Manufacturer’s Name and Address:
9.4 DIRECTIONS FOR USE: Directions for use of waterborne epoxy primer must include information on storage, surface preparation, mixing, thinning, application, and recoatability.
10.1 All materials (coatings) supplied under this speciﬁcation are subject to timely inspection by the purchaser or his authorized representative. The purchaser shall have the right to reject any materials supplied which are found to be defective under this speciﬁcation (see Note 12.1). In case of dispute, unless otherwise speciﬁed, the arbitration or settlement procedure established in the procurement documents shall be followed. If no arbitration or settlement procedure is established, then a procedure mutually agreeable to the purchaser and material supplier shall be used.
10.2 Samples of paints may be requested by the purchaser and shall be supplied upon request along with the manufacturer’s name and identiﬁcation for the materials. Samples may be requested at the time the purchase order is placed or may be taken from unopened containers at the job site.
10.3 Unless otherwise speciﬁed, the sampling shall be in accordance with ASTM D 3925.
11.1 While every precaution is taken to ensure that all information furnished in SSPC standards and speciﬁcations is as accurate, complete, and useful as possible, SSPC cannot assume responsibility nor incur any obligation resulting from the use of any materials, coatings, or methods speciﬁ ed herein, or of the speciﬁcation or standard itself.
11.2 This speciﬁcation does not attempt to address problems concerning safety associated with its use. The user of this speciﬁcation, as well as the user of all products or practices described herein, is responsible for instituting appropriate health and safety practices and for ensuring compliance with all governmental regulations.
Notes are not requirements of this speciﬁcation.
12.1 The procurement documents should establish the responsibility for samples, testing, and any required afﬁ davit certifying full compliance with the speciﬁcation.
12.2 VOC information may be supplied on the label or the technical data sheet.
12.3 ASTM D 3960 and EPA Method 24 are commonly used methods to determine VOC, but these methods may not be acceptable to all jurisdictions.
12.4 The 250 meter lot (800 ft lot) at the LaQue Center, Wrightsville (Kure) Beach, NC and the Neville Island and coke works sites in Pittsburgh, PA with average bare steel corrosion rates of one to three mils (25 to 75 micrometers) per year based on panels exposed for 12 months, have been shown suitable for this speciﬁcation’s exterior exposure. The test coatings used to establish the performance requirement were evaluated at these test sites.
12.5 The supplier should also furnish information on the volume solids and the theoretical spreading rate (square feet per gallon for one mil of dry paint) [square meters per liter for one micrometer of dry paint].
12.6 ASTM and Federal Standard Test Methods listed as “canceled” or “withdrawn” are no longer maintained, but are still available as historical documents.
PAINT SPECIFICATION NO. 28 – Water-Borne Epoxy Primer for Steel Surfaces