Single-Package Waterborne Alkyd Primer for Steel Surfaces, Performance-Based

Waterborne Alkyd Primer Application

PAINT SPECIFICATION NO. 31 – Single-Package Waterborne Alkyd Primer for Steel Surfaces, Performance-Based

1. Scope
1.1 This specification covers an air-drying, ready-mixed, pigmented, waterborne (i.e., water-reducible) alkyd or modified alkyd pigmented primer for blast cleaned steel. It is intended as the first coat of a waterborne coating system consisting of one or two coats of this primer and one or two coats of a waterborne topcoat.

1.2 This alkyd primer is suitable for exposures in Environmental Zones 1A (interior, normally dry), 1B (exterior, normally dry), 2A (frequently wet by fresh water [excluding immersion]) and 2B (frequently wet by salt water [excluding immersion]). See Note 11.1.

1.3 This primer is intended for brush, spray, or roller application over steel surfaces prepared in accordance with SSPC-SP 6, “Commercial Blast Cleaning.” 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, “Shop, Field, and Maintenance Painting of Steel.” If the primed part of the structure is to be exposed to the weather, it should be top-coated as soon as practical, according to the manufacturer’s published instructions.

1.4 This specification does not include primers based on latex polymers, which are described in SSPC Painting System 24.00.

2. Description
2.1 COMPOSITION
2.1.1 This alkyd primer is based on an ambient drying single-package vehicle which is rendered water-reducible via ionic solubility of the resin and appropriate pigments.
2.1.2 The polymer types are alkyds and copolymer alkyds (see Note 11.2). Latex polymers are excluded from this speci­fication.
2.1.3 The major volatile component by weight shall be water; however, volatile organic compounds may be present.
2.2 VOLATILE ORGANIC COMPOUND (VOC) CONTENT:
2.2.1 The VOC content of the primer shall be determined from the coating as applied, after recommended thinning. (See Section 4.2 and Note 11.4.)
2.3 PERFORMANCE LEVELS:
2.3.1 Primers shall be classified according to the perfor­mance achieved as follows:

• Level 1: Laboratory Testing (Section 5)
• Level 2: Exterior Exposure (Section 6)

2.3.2 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.
3.3 If there is a conflict between the requirements of any one of the cited reference standards and this specification, the requirements of this specification shall prevail.

3.4 SSPC STANDARDS AND JOINT STANDARDS:

3.5 ASTM INTERNATIONAL STANDARDS:
A 569 (Withdrawn) Specification for Steel, Carbon (0.15 Maximum Percent), Hot-Rolled Sheet and Strip, Commercial Quality Practice for Operating Salt Spray (Fog) Apparatus
B 117 Test Methods for Mandrel Bend Test of Attached Organic Coatings
D 522 Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using a Stormer-type Viscometer
D 562 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish,Conversion Coatings, and Related Coating Products
D 609 Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces
D 610 Test Method for Evaluating Degree of Blis­tering of Paints Test
D 714 Methods for Fineness of Dispersion of Pigment-Vehicle Systems by Hegman-type Gage
D 1210 Test Methods for Measurement of Wet Film Thickness of Organic Coatings
D 1212 Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes
D 1308 Test Method for Density of Liquid Coatings, Inks, and Related Products
D 1475 Test Methods for Drying, Curing, or Film Formation of Organic Coatings at Room Temperature
D 1640 Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments
D 1654 Test Method for Package Stability of Paint Test Method for Freeze-Thaw Resistance of Water Borne Coatings
D 1849 Practice for Testing Water Resistance of Coatings in 100% Relative Humidity
D 2243 Test Method for Volatile Content of Coatings
D 2247 Test Method for Resistance of Emulsion Paints in the Container to Attack by Micro­organisms
D 2369 Test Methods for Measuring Adhesion by Tape Test
D 2574 Test Method for Film Hardness by Pencil Test
D 3359 Practice for Sampling Liquid Paints and Related Pigmented Coatings
D 3363 Practice for Determining Volatile Organic Compound (VOC) Content of Paints and Related Coatings
D 3925 Test Method for Sag Resistance of Paints Using a Multinotch Applicator
D 3960 Test Methods for Field Measurement of Surface Profile of Blast-Cleaned Steel
G 92 Practice for Characterization of Atmospheric Test Sites

3.6 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD:
Z129.1 Hazardous Industrial Chemicals— Precautionary Labeling
3.7 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. Composition
4.1 The manufacturer is given latitude in the selection of materials and process of manufacture, provided that the primer meets the requirements of this specification. Materials shall be those used in good commercial practice and entirely suitable for the purpose intended under normal conditions of use.
4.2 The VOC content shall be measured by EPA Method 24, ASTM D 3960, or other approved methods. If no method is specified, use EPA Method 24. Supplier should provide information on the VOC content of the coating as supplied (in the container) and as applied (in the field after recommended thinning).
4.3 Pigments and other primer components shall contain a maximum of 0.06% by weight of lead or chromate in the dry film.

5. Laboratory Testing
5.1 For Level 1, the paint shall meet the requirements of Table 1 and Sections 5.2 through 5.12.
5.2 RESISTANCE TO MICROORGANISM ATTACK IN THE CONTAINER: The paint shall be resistant to attack by microorganisms when tested according to ASTM D 2574.
5.3 LABORATORY APPLICATION PROPERTIES: The primer shall be readily applied to a smooth steel vertical surface by brush, spray, or roller. A minimum of 4 mils (100 micrometers) wet film thickness shall be applied as measured by ASTM D 1212. Drying shall be done in a ventilated room or chamber free from drafts and dust and in diffused light, not in direct sunlight. The temperature of the air shall be between 70 and 77°F (21 and 25°C) and the relative humidity 50% ± 5%. There shall be no runs, sags, streaks, laps, pinholing, fisheyeing, or cratering. The dry film thickness of one coat as measured by SSPC-PA 2 shall not be less than 1.5 mils (38 micrometers). The primer shall be recoated at 24 and 48 hours according to the manufacturer’s recommendations. There shall be no picking-up, rolling-up, or lifting of the primer during recoat at 24 and 48 hours. Twenty-four hours after recoating, the film shall be smooth and uniform.
5.4 CONDITION IN CONTAINER: The primer as received shall show no evidence of skinning, or hard settling of the pigment. The inside of the container shall not be corroded. Any settled material shall be easily dispersed in the liquid portion by hand stirring to form a smooth, homogeneous consistency. The primer shall show a minimum of foaming and be free of grit, seeds, or lumps.
5.5 FREEZE/THAW RESISTANCE: The primer shall pass three cycles when tested according to the procedure described in ASTM D 2243. After cycling, there shall be no gelation or excessive thickening, coagulation, lumps, or coarse particles. The maximum allowable increase or decrease in viscosity shall not exceed 15 Krebs units. After being subjected to the above test, the primer shall also pass the tests outlined in Sections 5.3 and 5.4.
5.6 PACKAGE STABILITY: Perform the following tests in accordance with ASTM D 1849. When stored for one month at 124 to 127°F (51 to 53°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. After being subjected to the above test, the primer shall also pass the tests outlined in Sections 5.3 and 5.4.
5.7 MECHANICAL STABILITY: Fill a one-quart (one-liter) friction top can three-quarters full with the primer and close the can tightly. Rotate on a jar roller for 168 hours (one week) at 120 to 170 rpm. At the end of 168 hours, there shall be no indication of separation, coagulation, excessive foaming, exces­sive thickening, or loss in mechanical stability. The maximum allowable increase or decrease in viscosity shall not exceed 15 Krebs units. After being subjected to the above test, the primer shall also pass the tests outlined in Sections 5.3 and 5.4.
5.8 WATER INSENSITIVITY: Apply one coat of the water­borne primer by the drawdown method to a 4 x 8 inch (100 mm x 200 mm) cold-rolled steel panel (ASTM D 609, Type 2) to produce a dry film thickness of 2.0 ± 0.5 mils (50 ± 13 micrometers). Allow to dry at 70 to 77°F (21 to 25 °C) and 50% ± 5% relative humidity. After 24 hours drying time, subject the coating to a water spot test for four hours in accordance with ASTM D 1308. No blistering shall occur. The film may soften, but film integrity shall return after a 24 hour recovery period. Film integrity is defined as losing no more than one pencil hardness unit (ASTM D 3363) compared to the unexposed film (see Note 11.5).
5.9 SALT SPRAY AND HUMIDITY TESTING
5.9.1 Prepare six 4 x 8 x 1/8 inch (100 x 200 x 3.2 mm) ASTM A 569 hot rolled steel panels abrasive blasted in accor­dance with SSPC-SP 5 with a profile of 2.0 ± 0.5 mils (50 ± 13 micrometers) measured in accordance with ASTM D 4417. Apply one coat of primer to produce a dry film thickness of
2.0 ± 0.5 mils (50 ± 13 micrometers) on all eight panels. Four panels shall dry 48 hours before a second coat of primer is applied so as to obtain a total thickness of 3.5 ± 0.5 mils dry (90 ± 13 micrometers). These panels and the single prime coat panels shall be allowed to dry for an additional 14 days. Coat and seal all edges and the back side with a suitable protective coating.
5.9.2 Scribe two single prime and two double prime panels to produce a 5 inch (13 mm) vertical cut exposing the underlying metal. Conditions of making the scribe shall be as described in ASTM D 1654.

5.9.3 Expose the four scribed panels (two single prime and two double prime) in the salt fog cabinet operated according to ASTM B 117. After the specified number of hours, the panels shall be removed, dried, and rated for blistering according to ASTM D 714. After rating for blistering, immediately remove the paint film with the aid of a spatula or razor blade. Examine the steel substrate for corrosion and rust creepage according to ASTM D 1654. The condition may be preserved by applying a clear varnish.
The ratings of the panels shall be:

• one coat primer exposed 240 hours will give corrosion of 8 or better, scribe 7 or better and a blister  rating 2F or better.
• two coat primer exposed 500 hours will give corrosion of 8 or better, scribe of 7 or better, and a  blister rating of 2F or better.

5.9.4 The remaining two double prime panels shall be exposed on the Cleveland Condensing Humidity Cabinet operated according to ASTM D 2247 and should be rated by ASTM D 714 and ASTM D 1654 Method B — double prime exposed 96 hours will give corrosion of 8 or better and blistering of 2F or better.

5.10 ADHESION: The coating, when applied and dried in accordance with the conditions in Section 5.11, and subjected to the “Cross-Cut Tape Test” (ASTM D 3359, Method B) shall have an adhesion rating no less than “4B” grading.
5.11 EARLY RUST RESISTANCE TEST
5.11.1. Prepare two 4 x 8 x 1/8 inch (100 x 200 x 3.2 mm) hot rolled steel panels by blast cleaning to white metal according to SSPC-SP 5. Allow brush, paint, and panels to equilibrate in a controlled environment chamber maintained at 48 to 52°F (9 to 11°C) and 75 to 80% relative humidity for at least 30 minutes. Apply the paint by brushing to a dry film thickness of 1.5 ± 0.5 mils (38 ± 13 micrometers) and allow to cure for 16 hours in the controlled environment.
5.11.2 Remove the panels from the chamber and support them facing up about 1/2 inch (13 mm) above a water trough containing 1 inch (25 mm) of cold (48 to 52°F [9 to 11°C]) water. Place a piece of cheesecloth over the panels and sprinkle cold (48 to 52 °F [9 to 11°C]) water on it. Make sure the cheesecloth is always totally wet during the complete test period. At the end of 24 hours no sign of early rusting shall be allowed.
5.12 FLEXIBILITY: Flexibility shall be determined in accordance with ASTM D 522 Method B. Apply a 2 inch (50 mm) wide film of the paint with a film applicator that will give a dry film thickness of 2.0 ± 0.5 mil (50 ± 13 micrometers) on a smooth finish steel panel, prepared in accordance with ASTM D 609, paragraph 5.3 Method C, using the aliphatic naphtha propylene glycol monomethyl ether mixture. The panel shall be new, cold rolled, rust-free carbon steel No. 22 gage as defined by Type No. 1 in Table 1 of ASTM D 609. The coated panel shall air dry for 24 hours at a temperature of 70 to 77°F (21 to 25°C) and then shall be put in an oven at 98 to 102°F (37 to 39°C) for four days. Condition the panel at 70 to 75 °F (21 to 25°C) for two hours. Bend panel over a 1/4 inch (6.4 mm) mandrel. Examine the bend for paint cracking visible to the unaided eye. There shall be no visible cracking.

6. Test Fence Performance Requirements
6.1 For Level 2, the paint shall meet the requirements of Sections 6.2, 6.3, and those of Level 1.
6.2 Three “double prime” panels shall be prepared as described in 5.9.1. The dry film thickness shall be 3.5 ± 0.5 mils (90 ± 13 micrometers). A set of solvent alkyd control panels using SSPC-Paint 25 must be exposed concurrently. The panels shall be scribed as described in Section 5.9.2.
6.3 EXTERIOR EXPOSURE: Triplicate test panels shall be exposed for a minimum of 18 months at a test fence at an industrial or marine exposure site with a minimum annual mean precipitation of 25 inches (625 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 minimum mean annual temperature, may also be required when agreed to between contracting parties. (See Note 11.6.) Each specimen shall meet the following requirements:

• Minimum rust rating of 8 in accordance with SSPC-VIS 2/ASTM D 610
• Maximum scribe undercutting of 1/16 inch (0.8 mm)

7. Material Quality Assurance
7.1 The manufacturer should measure and record batch testing information that would allow certification that a batch of paint meets the necessary standards established by the manufacturer for the alkyd primer as tested per Sections 5 and 6.
7.2 COLOR: The color shall be as specified in the procure­ment documents.
7.4 VISCOSITY: The viscosity of the mixed primer shall be determined in accordance with ASTM D 562. Variance shall be within ± 5 Krebs Units, or equivalent units of another viscometer, of the viscosity of the previously qualified primer.
7.5 DENSITY: 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.
7.6 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 (see Note 11.7).

8. Labeling
8.1 Labeling shall conform to ANSI Z129.1.
8.2 Technical data shall be provided for at least all data elements categorized as “essential” in SSPC-Guide 13.
8.2 MARKING OF CONTAINERS: Each container shall be legibly marked with the following information:
Name: Single Package Waterborne Alkyd Primer for Steel Surfaces, Performance-Based
Specification: SSPC-Paint 31
Color:
Lot No.:
Stock No.:
Date of Manufacture:
Quantity of Paint in Container:
Information and Warnings as may be required by
Federal and State Laws:
VOC Content (see section 4.2):
Manufacturer’s Name and Address:
Keep from Freezing

8.3: DIRECTIONS FOR USE: The directions for use should be supplied by the manufacturer with each container of paint. If no directions are furnished, the directions in Note 11.8 should be used.

9. Inspection
9.1 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 11.3). 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.
9.2 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.
9.3 Unless otherwise specified, the sampling shall be in accordance with ASTM D 3925.

10. Disclaimer
10.1 While every precaution is taken to ensure that all information furnished in SSPC standards and specifications are 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.
10.2 This specification of alkyd primer 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.

11. Notes
Notes are not requirements of this specification.
11.1 Environmental Zone Descriptions

• 1A –  Interior, normally dry (or temporary protection). Very mild (oil base paints now last six years or more).
• 1B  –   Exteriors, normally dry (includes most areas where oil base paints now last six years or more)
• 2A  –   Frequently wet by fresh water. Involves condensation, splash, spray, or frequent immersion (oil   base paints now last five years or less).
• 2B  –   Frequently wet by salt water. Involves condensation, splash, spray, or frequent immersion (oil base  paints now last three years or less).

11.2 Primers based on water-reducible epoxy esters may also meet the performance requirements of this specifica­tion.
11.3 The procurement documents should establish the responsibility for samples, testing, and any required affidavit certifying full compliance with the specification.
11.4 The primer may not comply with all air pollution regula­tions. Consult applicable government regulations to determine maximum allowable VOC and proper VOC determination test method for a particular application.
11.5 Pencil hardness units are as follows: 6B (softest), 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H (hardest).
11.6 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, with average bare steel corrosion rates of one to three mils (25 to 76 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.

11.7 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].

11.8 DIRECTIONS FOR USE OF SINGLE-PACKAGE WATERBORNE ALKYD PRIMER FOR STEEL SURFACES, PERFORMANCE-BASED:

This paint is intended for use as a primer over blast cleaned steel in atmospheric exposure. It is intended as the first coat of a waterborne coating system consisting of two coats of this primer and one or two coats of a waterborne topcoat. It may also be used over previously coated surfaces after compatibility has been established.

Mix paint thoroughly before use. If the pigment has settled, pour off most of the liquid. Thoroughly mix the pigment with the remaining liquid, taking care to scrape all the pigment off the bottom of the can. Gradually add the poured-off liquid and mix thoroughly. Mixing may be made easier by transferring contents to a larger container or by pouring the paint to and from another container. Examine the bottom of containers for unmixed pigment. Screen paint before applying.

Thin paint only if necessary, using only deionized or potable water. For brush application under normal conditions, no thinning should be necessary. For spray applications add up to one-half pint of water per gallon of paint (62 cc per liter) when necessary.

This paint may be applied by spray, brush, or roll. Cross-brushing or cross spraying application is highly desir­able. Application by spray tends to provide the best leveling. Apply to the specified film thickness, or, if none is specified, to at least 1.5 mils (38 micrometers) dry or approximately 6 mils (150 micrometers) wet. If the primed part of the structure is to be exposed to the weather, it should be top-coated as soon as practical.

The atmospheric conditions at the time this coating is applied are extremely important. This primer shall not be applied at a temperature below 40°F (4°C) or above 120°F (49°C). The manufacturer’s recommendations on humidity and dew point shall be followed.

The best conditions for storage of this coating are at temperatures between 40°F (4°C) and 75°F (24°C). This coating shall never be allowed to attain temperatures over 120°F (49°C) or subjected to repeated freezing and thawing. When stored at temperatures of 120°F and above (49°C and above), shelf life is decreased markedly.

Allow paint at least 24 hours drying time in good weather before re-coating.

Consult coating manufacturer regarding “dry to handle” times for shop-applied coatings.

PAINT SPECIFICATION NO. 31 – Single-Package Waterborne Alkyd Primer for Steel Surfaces, Performance-Based