Waterborne Epoxy Coating
PAINT SPECIFICATION NO. 37 – Waterborne Epoxy Coating for Cementitious Substrates Performance-Based
1.1 This speciﬁcation covers the requirements for an ambient temperature cure, two-component waterborne epoxy coating that is intended for use as a coating for concrete.
1.2 Coatings 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).
1.3 The speciﬁed epoxy coating is intended for application by brush, roller, and spray over surfaces prepared in accordance with the manufacturer’s written recommendations.
2.1.1 This epoxy coating is typically based on a reactive epoxy functional resin with an amine or acid functional curing agent effective for anti-corrosion (see Section 4.2).
2.1.2 The major volatile component by weight is water (see Section 4.3).
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. Those documents marked with an asterisk (*) are referenced only in the Notes or the Appendix, 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:
Guide for the Identiﬁcation and Use of Industrial Coating Material in Computerized Product Databases
Procedure for Applying Thin Film Coatings to Concrete
SP 13/NACE No. 6
Surface Preparation of Concrete
* TU 2/NACE 6G197
Informational Report and Technology Update on Design, Installation, and Maintenance of Coating Systems for Concrete Used in Secondary Containment
3.4 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS:
2D 523 Test Method for Specular Gloss
D 562 Test Method for Consistency of Paint Measuring Krebs Unit (KU) Viscosity Using a Stormer-type Viscometer
D 660 Test Method for Evaluating Degree of Checking of Exterior Paints
D 661 Test Method for Evaluating Degree of Cracking of Exterior Paints
D 714 Test Method for Evaluating Degree of Blistering of Paints
D 968 Test Methods for Abrasion Resistance of Organic Coatings by Falling Abrasive
* D 1296 Test Method for Odor of Volatile Solvents and Diluents
D 1308 Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes
* D 1475 Test Method for Density of Liquid Coatings, Inks, and Related Products
* D 1535 Practice for Specifying Color by the Munsell System
* D 1640 Test Methods for Drying, Curing, or Film Formation of Organic Coatings at Room Temperature
D 1734 Practice for Making Cementitious Panels for Testing Coatings
D 2196 Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational (Brookﬁeld) Viscometer
D 2243 Test for Freeze-Thaw Resistance of Waterborne Coatings
D 2244 Test Method for Calculation of Color Differences from Instrumentally Measured Color Coordinates
D 2369 Test Method for Volatile Content of Coating
* D 2371 Test Method for Pigment Content of Solvent-Reducible Paints
D 2574 Test Method for Resistance of Emulsion Paints in the Container to Attack by Microorganisms
* D 2621 Test Method for Infrared Identiﬁcation of Vehicle Solids from Solvent-Reducible Paints
D 3359 Test Methods for Measuring Adhesion by Tape Test
D 3363 Test Method for Film Hardness by Pencil Test
D 3723 Test Method for Pigment Content of Water-Emulsion Paints by Low-Temperature Ashing
D 3792 Test Method for Water Content of Water-Reducible Paints by Direct Injection into a Gas Chromatograph
D 3925 Practice for Sampling Liquid Paints and Related Pigmented Coatings
D 4017 Test Method for Water in Paints and Paint Materials by Karl Fischer Method
D 4585 Practice for Testing the Water Resistance of Coatings Using Controlled Condensation
D 6132 Test Method for Nondestructive Measurement of Dry Film Thickness of Applied Organic Coatings Over Concrete Using an Ultrasonic Gage
3.5 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD:
Z129.1 Hazardous Industrial Chemicals— Precautionary Labeling
3.6 FEDERAL SPECIFICATIONS AND STANDARDS:
FED-STD-141: Paint, Varnish, Lacquer and Related Materials: Methods of Inspection, Sampling, and Testing
Method 3011 Condition in Container
Method 4321 Brushing Properties
Method 4331 Spraying Properties
Method 4541 (canceled) Working Properties and Appearance of Dried Film
4. Composition Requirements
4.1 The manufacturer is given wide latitude in the selection of materials and manufacturing processes (see Note 12.1).
4.2 EPOXY RESIN REQUIREMENT: The epoxy resin together with the curing agent, as described in Section 2.1.1, shall constitute at least 40% by weight of total solids. Determine the weight percent nonvolatile solids (TS) in accordance with ASTM D 2369. Determine the weight percent pigment (P) of the mixed coating in accordance with ASTM D 3723. Allow the mixed epoxy coating to air dry for 24 hours prior to ashing. Calculate the percent vehicle solids (VS) as follows:
TS – P
VS = • 100%
4.3 WATER REQUIREMENT: Water shall constitute at least 70% of the weight and volume of volatile solvent. The water content shall be determined in accordance with ASTM D 3792 or ASTM D 4017.
5. Standard Testing Conditions
5.1 SUBSTRATE: The concrete test panels shall conform to ASTM D 1734. Surface preparation shall conform to “Light Service” as described in Table 1 of SSPC-SP 1 (see Note 12.2).
5.2 APPLICATION: Thoroughly mix together both components of the epoxy coating following the manufacturer’s written instructions. Allow the mixture to stand for the manufacturer’s speciﬁed induction time, if stated. Apply the epoxy coating in accordance with manufacturer’s written instructions.
5.3 DRY FILM THICKNESS: The dry ﬁlm thickness (DFT) shall be within the manufacturer’s written recommended range. If there is no recommended ﬁlm thickness, then the minimum thickness shall be 50 micrometers (2.0 mils). The ﬁlm thickness shall be measured in accordance with ASTM D 6132.
5.4 CURE: All coated panels to be tested will be allowed to cure for a minimum of seven days under ambient laboratory conditions before physical testing is to begin.
6. Requirements for the Liquid Coating
6.1 RESISTANCE TO MICROORGANISMS IN CONTAINER: The liquid coating shall be resistant to attack by microorganisms when tested in accordance with ASTM D 2574.
6.2 FREEZE-THAW RESISTANCE: Test both components of the two-pack system separately in accordance with ASTM D 2243. At the end of three cycles there shall be no gelling, coagulation, lumps, or coarse particles. The change in viscosity shall not exceed 10% of original viscosity as run by ASTM D 562 or ASTM D 2196.
6.3 PACKAGE STABILITY: Measure the viscosity of both components of the two-pack epoxy coating separately in accordance with ASTM D 562 or ASTM D 2196. Then place each component in an appropriate closed container (i.e., a lined metal or plastic can) in an oven at 52 ± 1˚C (125 ± 2˚F). After 30 days, remove the epoxy coating from the oven and measure the viscosity of each component of the coating. The change in viscosity shall not exceed 10% of original viscosity. After mixing the aged components according to the manufacturer’s written instructions and brushing out, the ﬁlm shall be free from grains, lumps, or streaks.
6.4 MECHANICAL STABILITY: Test both components of the two-pack system separately. Fill a one-liter (approximately one quart) friction top can three-fourths full and secure tightly. In an environment at 75˚ ± 5˚F (24˚ ± 3˚C), rotate the can on a jar roller for one week at 120 to 170 rpm. At the end of one week, there shall be no separation, coagulation, excessive thickening, loss in mechanical stability, or changes in viscosity greater than 10% of the original viscosity.
6.5 POT LIFE: Mix the epoxy coating per Section 5.2 to yield one liter (approximately one quart) of prepared coating. Allow the mixed coating to stand at ambient laboratory conditions for the pot lifetime speciﬁed by the manufacturer. At the end of this time period, the coating shall show no evidence of gelation and still meet the requirements of Sections 7.1 and 7.3.
7. Laboratory Tests of Applied Films
7.1 APPLICATION PROPERTIES: Prepare the liquid paint per Section 5.2. The paint shall be easily applied by brush, roller, and spray when tested in accordance with FEDSTD-141, Methods 4321, 4331, and 4541. The paint shall show no streaking, running, or sagging during application or while drying.
7.2 RECOAT TESTS: Coat a test panel in accordance with Section 5. Apply one additional coat in accordance with Sections 5.2 and 5.3. There shall be no picking-up or rolling-up of the previous coat during application. Twenty-four hours after application of the second coat, the ﬁlm shall be smooth and uniform. Twenty-four hours after application of the second coat, adhesion shall be 4A, 5A, 4B, or 5B when tested in accordance with ASTM D 3359.
7.3 FILM INTEGRITY: Mix coating per Section 5.2. Apply one coat by brush or roller application in accordance with Sections 5.3 and 5.4. Evaluate for checking and cracking in accordance with ASTM D 660 and D 661, respectively. Any checking or cracking rating less than 10 is cause for rejection.
7.4 ABRASION RESISTANCE: Evaluate abrasion resistance in accordance with ASTM D 968. Liters of abrasive material per mil of ﬁlm loss shall be greater than 20.
7.5 CHEMICAL RESISTANCE: Apply the coating to two replicate panels in accordance with Section 5. Test chemical resistance in accordance with the closed spot test of ASTM D 1308 using a mixture of n-octane (80%) and toluene (20%). (See Note 12.3.) After 4 hours exposure, for each replicate panel the coating shall exhibit:
- a blister rating of 10 (no blisters) per ASTM D 714;
- no discoloration per ASTM D 2244;
- a change of gloss less than 10 percent per ASTM D 523;
- no softening per ASTM D 3363.
7.6 ADHESION EVALUATION: When tested in accordance with ASTM D 3359, adhesion shall be 4A, 5A, 4B, or 5B.
7.7 CONDENSING HUMIDITY CABINET TEST: Two replicate panels prepared per Section 5 shall be exposed for 500 hours in a condensation cabinet in accordance with ASTM D 4585. After 500 hours, the blister rating of each replicate panel shall be 10 (no blistering) per ASTM D 714.
7.8 EARLY WATER RESISTANCE: Apply one coat of the coating in accordance with Sections 5.1 through 5.3. Allow to dry in a horizontal position for 24 hours after coating. At the end of the drying period, immerse one-half of the panel in distilled water for one hour. Remove the panel and allow the system to condition for 30 minutes at 73.5 ± 3.5˚F (-23 ± 2˚C). The exposed section of coating shall have the same color, gloss, and hardness as the unexposed section when checked according to ASTM D 2244, D 523, and D 3363, respectively (see Notes 12.4 and 12.5.)
8. Material Quality Assurance
8.1 If the user chooses, tests may be used to determine the acceptability of a lot or batch of a qualiﬁed coating (see Note 12.6.)
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.
10.1 All materials supplied under this speciﬁcation are subject to timely inspection by the purchaser or an authorized representative. The purchaser shall have the right to reject any materials supplied, which are found to be defective under this speciﬁcation (see Note 12.7). In case of dispute, unless otherwise speciﬁed, the arbitration or settlement procedure established in the procurement documents shall be followed. If no arbitration procedure is established, then a procedure 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, and batch number 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 speciﬁed 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 VOC CONTENT: Each coating, after recommended thinning, must conform to published government regulations regarding volatile organic compound (VOC) content. VOC information should be supplied on the label or the technical data sheet. Various governmental agencies may have different VOC limits or use different methods of testing. The owner may modify this speciﬁcation as necessary to specify a particular VOC content limit consistent with local regulations. Coatings meeting the composition and performance requirements of this speciﬁcation usually have a VOC level less than 250 g/L (2.1 lb/gal).
12.2 Surface preparation is extremely important for the successful ﬁeld application of coatings to concrete. SSPC documents that pertain to coating concrete are SSPC-SP 13/NACE No. 6, SSPC-PA 7, and SSPC-TU 2/NACE 6G197.
12.3 For special applications, the contracting parties may agree to test with additional reagents and other exposure times.
12.4 The contracting parties may agree to change dry times and exposure times.
12.5 Epoxy systems will tend to chalk and lose gloss when exposed to ultraviolet light. Top-coating per the manufacturer’s written instructions may be desired where gloss retention and chalking resistance are required.
12.6 QUALITY ASSURANCE TESTS: The quality assurance tests are used to determine whether the supplied products are of the same type and quality as those originally tested and certiﬁed for acceptance. The selected tests should accurately and rapidly measure the physical and chemical characteristics of the coating necessary to verify that the supplied material is substantially the same as the previously accepted material. All of the quality assurance tests must be performed on the originally submitted qualiﬁcation sample. The results of these tests are used to establish pass/fail criteria for quality assurance testing of supplied products.
12.6.1 Establishing Quality Assurance Acceptance Criteria: Many ASTM test methods contain precision and bias statements. Speciﬁcation developers should be cognizant of the fact that these statements exist. Quality assurance test criteria should not be more stringent than the inter-laboratory precision of the test methods used.
Example: A common quality assurance test is density (weight per gallon) as measured by ASTM D 1475. The inter-laboratory reproducibility at the 95% conﬁdence level tells us that any two measurements that differ by more than 1.8% should be considered suspect. This only represents the precision of the measurement technique and does not account for normal variances in the manufactured product.
The acceptable range for paint density must be stated. For example, a composition speciﬁcation may state this requirement as 10.0 ± 0.2 lb/gal, 10.0-lb/gal ± 2%, or as a range from 9.8 to 10.2 lb/gal. The manufacturer of proprietary products should provide this information. Using these values, if the manufacturer’s lab measures the density to be 9.8 lb/gal, the product meets the speciﬁcation and the paint is shipped to the job. Because of the lab-to-lab variation of 1.8%, the user’s lab may measure the density of this sample to be as low as 9.8 less 1.8% of 9.8 (= 9.6 lb/gal). Similarly for the high end, the manufacturer may measure density of 10.2 lb/gal while the user measures 10.2 + 1.8% (= 10.4 lb/gal). The pass/fail criteria for the user to accept a batch of paint should therefore be 9.6 to 10.4 lb/gal.
Where precision and bias data are not available for a given test method, determine the standard deviation of a minimum of ﬁve measurements taken on the originally tested and certiﬁed material. The pass/fail criterion is that the measurement of the test sample shall fall within two standard deviations of the target value. The contracting parties must agree on a target value.
12.6.2 Recommended Quality Assurance Tests: Recommended quality assurance tests include, but are not limited to, infrared analysis (ASTM D 2621), viscosity (ASTM D 562), weight per gallon (ASTM D 1475), total solids (ASTM D 2369), dry time (ASTM D 1640), percent pigment (ASTM D 2371), gloss (ASTM D 523), color (ASTM D 1535), condition in container (FED-STD-141, Method 3011), and odor (ASTM D 1296).
12.7 The procurement documents should establish the responsibility for samples, testing, and any required afﬁdavit certifying full compliance with the speciﬁcation.
12.8 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. 37 – Waterborne Epoxy Coating for Cementitious Substrates Performance-Based