Latex Painting System for Industrial and Marine Atmospheres
PAINTING SPECIFICATION NO. 24.00 – Latex Painting System for Industrial and Marine Atmospheres
1. Scope
1.1 This specification covers a painting system for steel surfaces based on multiple coats of air-drying, single-component latex paints having a total dry film thickness of a minimum of six mils (152 micrometers).
1.2 A painting system is categorized according to its performance level over blast-cleaned steel, the intended substrate (See Note 11.1).
1.3 The system is suitable for exposure in Environmental Zones IA (interior, normally dry), IB (exterior, normally dry), 2A (frequently wet by fresh water), 2B (frequently wet by salt water), 3A (chemical exposure, acidic), 3B (chemical exposure, neutral), 3C (chemical exposure, alkaline) and 3D (chemical exposure, mild solvent).
1.4 The system is not intended for immersion service.
2. Description
2.1 SYSTEM COMPOSITION: The painting system is comprised of paints based on pigmented emulsion (latex) binders.
2.2 VOC CONTENT:
2.2.1 The painting system may or 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. The manufacturer shall provide VOC information about the paints as supplied (in the container) and as applied in the field after recommended thinning (See Notes 11.2 and 11.3).
2.3 PERFORMANCE LEVELS
2.3.1 Painting systems shall be classified according performance achieved as follows:
Level 1: Accelerated Laboratory Testing Level 2: Test Fence and Laboratory Evaluation Level 3: Long-Term Exterior Exposure
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.
3.2 If there is a conflict between the requirements of any of the cited referenced standards and this specification, the requirements of this specification shall prevail.
3.3 SSPC STANDARDS:
PA 1 Shop, Field, and Maintenance Painting of Steel
SP 5/NACE No. White Metal Blast Cleaning
VIS 2 Standard Method of Evaluating
Degree of Rusting on Painted Steel Surfaces
3.4 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS:
B 117 Standard Practice for Operating Salt
Spray (Fog) Apparatus
D 523 Standard Test Method for Specular Gloss
D 562 Standard Test Method for Consistency of Paints Using the Stormer Viscometer
D 610 Standard Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces
D 714 Standard Test Method for Evaluating Degree of Blistering of Paints
D 1200 Standard Test Method for Viscosity by Ford Viscosity Cup
D 1211 Standard Test Method for Temperature-Change Resistance of Clear Nitrocellulose Lacquer Films Applied to Wood
D 1475 Standard Test Method for Density of Liquid Coatings, Inks, and Related Products
D 1654 Standard Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environment
D 2369 Standard Test Method for Volatile Content of Coatings D 3359 Standard Methods for Measuring Adhesion by Tape Test
D 3925 Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings
D 3960 Standard Practice for Determining Volatile Organic Content (VOC) of Paints and Related Coatings
D 4417 Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel
D 4587 Standard Practice for Conducting Tests on Paint and Related Coatings and Materials Using a Fluorescent UV Condensation Light- and Water-Exposure Apparatus
G 53 Operating Light- and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) For Exposure of Non-Metallic Materials (Withdrawn 2000; Replaced with ASTM G 155.)
G 92 Standard Practice for Characteristics of Atmospheric Test Sites
G 151 Standard Practice for Exposing Non-Metallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
3.6 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD:
Z129.1 Hazardous Industrial Chemicals— Precautionary Labeling
3.7 FEDERAL STANDARDS:
EPA Method 24 Determination of Volatile Matter Content, Water Content, Density, Volume Solids and Weight Solids of Surface Coatings (40 CFR Ch1, Part 60, Appendix A)
4. Composition
4.1 VEHICLE: The vehicle for the paints in this painting system is based on a stable polymer emulsion in an aqueous medium.
4.2 PIGMENT: The primer may contain environmentally compliant corrosion-inhibiting pigments. This does not preclude use of a non-inhibitive pigment-containing primer as long as the requirements of this specification are met.
4.3 GENERAL: The manufacturer is given latitude in the selection of other compositional ingredients provided that the paint and the painting system meet the requirements of this specification.
5. Performance Requirements
5.1 ACCELERATED LABORATORY TESTING (LEVEL 1): For Level 1 the painting system shall meet the requirements of Sections 6.2 through 6.4.
5.2 TEST FENCE AND LABORATORY EVALUATION (LEVEL 2): For Level 2 the painting system shall meet the requirements of Sections 6.2, 6.3, and 6.5.
5.3 LONG-TERM EXTERIOR EXPOSURE (LEVEL 3): For Level 3 the painting system shall meet the requirements of Sections 6.2, 6.3, and 6.6. (See Note 11.4.)
6. Testing Procedures
6.1 STANDARD LABORATORY TESTING CONDITIONS: For purposes of this specification, standard temperature shall be 73.5 ± 3.5°F (23 ± 2°C) and standard relative humidity shall be 50% ± 5%. The standard substrate shall be 4 inch x 12 inch x 1/8 inch (10 cm x 31 cm x 3.2 mm) thick ASTM A 569 hot-rolled steel abrasive blasted in accordance with SSPC-SP 5 to a profi le of 1.7 ±0.5 mils (43 ± 13 micrometers). Measure blast profile in accordance with ASTM D 4417.
6.2 ADHESION: Apply the complete paint system to two panels according to the manufacturer’s suggested finishing schedule. After drying for 14 days at standard conditions, adhesion of the system to the steel shall be determined using the ASTM D 3359 cross-hatch adhesion test. Each of the specimens shall have a minimum adhesion rating of 3A.
6.3 EARLY RUST RESISTANCE OF SYSTEM:
6.3.1 Prepare and equilibrate a refrigerator at 50°F (10°C) and approximately 75 to 80% relative humidity. Condition the paints to be applied and the panels in the refrigerator for at least 45 minutes.
6.3.2 Remove panels from refrigerator and apply one coat of primer, 1.4 to 1.8 mils (36 to 45 micrometers) dry above the profile, and return panels to the refrigerator. Dry for four hours or until film is dry to touch (See Notes 11.5 and 11.6.). Again remove panels and apply one coat of topcoat (preferably white) at 1.4 to 1.8 dry mils (36 to 46 micrometers) and return panels to the refrigerator. Dry until film is dry to touch.
6.3.3 Expose panels under continuous wet or condensing conditions at ambient temperature for approximately 16 hours (See Note 11.7). At the end of 16 hours, immediately examine for rusting and blistering. The rusting shall not exceed 9 as judged by SSPC-VIS 2, and blistering shall not exceed 8F according to ASTM D 714.
6.4 ACCELERATED LABORATORY TESTING:
6.4.1 Accelerated Weathering Test: Apply the painting system to four panels, prepared as described in Section 6.1, according to the manufacturer’s recommendations. After drying for two weeks at standard conditions, expose panels in the apparatus described in ASTM G 53 (equipped with a UVA-340 Bulb) for 1,000 hours. (See Note 11.8.) The test cycle is four hours UV exposure (135°F, 57°C) followed by four hours of condensation (112°F, 44°C) (See Note 11.9). There shall be no cracking, rusting, or blistering (See Note 11.10).
6.4 .2 Thermal Shock Test:Allow panels tested in Section
6.4.1 to equilibrate at least 16 hours. Test panels in accordance with the painting system procedure of ASTM D 1211 for ten cycles. One cycle in this test constitutes a period of high temperature followed by exposure to low temperature and then a return to room temperature. Panels should be patted dry with cheesecloth if wet, taking care not to disturb the coated surface. There shall be no checking or cracking (See Note 11.11).
6.4.3 Salt Fog Test: Allow panels tested in Section 6.4.2 to equilibrate for at least 16 hours. Scribe a four-inch (100 mm) vertical line on the lower portion of the panel one inch (25 mm) from the bottom edge. The conditions of making the scribe shall be as described in ASTM D 1654. Expose panels in the salt fog cabinet according to ASTM B 117. Panels shall be examined for rusting and blistering at 96-hour intervals for a period of 500 hours. The rusting shall not exceed 8 according to SSPC-VIS 2 or ASTM D 610, and blistering shall not exceed 8F according to ASTM D 714. Undercutting at the scribe, according to ASTM D 1654, shall not exceed 1/8 inch (3.2 mm) from the center of the scribe.
6.5 TEST FENCE AND LABORATORY EVALUATION:
6.5.1 Apply the painting system to four panels and allow to dry for two weeks, in accordance with Section 6.1.
6.5.2 Expose panels for a minimum of 12 months on a test fence at an industrial or marine site having a minimum annual mean precipitation of 25 inches (635 mm) per year (See Note 11.12). 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 by the purchaser (See Note 11.13).
6.5.3 The rusting shall not exceed 9 as indicated by SSPC-VIS 2 or ASTM D 610, and there shall be no blistering as judged by ASTM D 714.
6.5.4 The panels shall then be subjected to the Thermal Shock Test (and rated as described in Section 6.4.2) followed by the Salt Fog Test (and prepared and rated as described in Section 6.4.3).
6.6 LONG-TERM EXTERIOR EXPOSURE: Test panels coated as described in Section 6.4.1 shall be exposed for a minimum of 36 months as described in Section 6.5 and examined for rusting and blistering. The rusting shall not exceed 9 as judged by SSPC-VIS 2 or ASTM D 610. There shall be no blistering (See Note 11.13).
7. Material Quality Assurance
7.1 The supplier of the painting system shall certify that the products furnished are essentially identical formulations to those used in qualification testing.
7.2 The paint shall meet the requirements of Sections 7.3 through 7.8.
7.3 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.
7.4 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 of the mixed paint shall be determined in accordance with ASTM D 1475. Variance shall be within ±0.4 pounds/gallon (50 g/l) of the density of the previously qualified paint.
7.6 Solids percent by weight of the mixed paint shall be determined in accordance with ASTM D 2369. Variance shall be within ±2% of the percent solids by weight of the previously qualified paint.
7.7 The paint manufacturer and the purchaser shall agree on an acceptable shelf life for the painting system.
7.8 Other tests may be used to determine the acceptability of a lot or batch of a qualified product at the discretion of the purchaser.
8. Labeling
8.1 Refer to ANSI Z129.1. Other guidelines can be found in the National Paint and Coating Association (NPCA) “Paint Industry Labeling Guide.”
8.2 MARKING OF CONTAINER: Each container shall be legibly marked with the following information:
Name: Latex Painting System (Primer or Topcoat)
Specification: SSPC Painting System PS 24.00
Color:
Lot Number:
Batch Number:
Stock Number:
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:
8.3 DIRECTIONS FOR USE: The manufacturer shall supply complete instructions covering uses, surface preparation, mixing, thinning, volume solids, application methods, application conditions, pot life, wet and dry film thicknesses, temperature and humidity limitations, drying times, etc., with each container of paint.
9. Inspection
9.1All 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 11.14.). 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 purchaser, material supplier, and contractor 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 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.
10.2 This painting system 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 insuring compliance with all governmental regulations.
11. Notes
Notes are not requirements of this specification.
11.1 The painting system may also be applied over sound painted surfaces in multiple coats of lower dry film thickness (three mils [76 micrometers] minimum total thickness).
11.2 VOC information may be provided on the container label or the technical data sheet.
11.3 ASTM D 3960 and EPA Method 24 are the most commonly used methods to determine VOC content.
11.4 This specification describes a painting system designed to achieve long-term protection of the substrate. A detailed documentation of successful case histories of actual field performance may be used as an alternative to the specified testing regimen if agreed upon by the contracting parties. The paint supplier should furnish evidence of satisfactory long-term performance of the system in conditions similar to those of the specifier’s environment.
11.5 EARLY RUST RESISTANCE:
11.5.1 In a cool, damp application environment, proper development of water-borne products is inhibited and early rusting can result. The paint supplier should be required to furnish documentation verifying the ability of the system to meet the early rust resistance requirements of this specification. Documentation should include laboratory test data simulating application under the conditions described in Section 6.3 and sufficient field test work to confirm the laboratory test data.
11.5.2 The Early Rust Resistance Test has been designed to expose the system to an extremely harsh environment. In this test, paint is applied in thin coats to a cool, active metal surface which is subjected to conditions of dampness for an extended period. Although successful performance in the test virtually assures excellent early rust resistance of the system, failure is not necessarily indicative of early rusting failure in the field.
11.6 If the relative humidity in the laboratory area is 70% or greater at ambient room temperature (70°F, 21°C) or higher, the film will not dry to touch. If this condition occurs, the panel should be placed in a controlled environment meeting the conditions of Section 6.1.
11.7 A suggested procedure for this phase of the test is as follows. Use a pan of water in which the panels are suspended just above the water surface, horizontally face up. Cover the panels with wet cheesecloth, the ends of which are immersed in the water, to provide constant wicking and assurance that the panel surfaces are kept continually wet. Enclose the entire apparatus with a foil lid to insure constant humidity. Other apparatuses which provide these severe drying conditions can also be used.
11.8 Paints harden on aging via solvent loss, oxidation, or curing. Excessive hardening can lead to adhesion/cracking/flaking failures. This accelerated weathering step is an attempt to test laboratory films that are approaching ultimate hardness.
11.9 An alternative testing cycle, with eight hours UV exposure (140°F, 60°C) followed by four hours condensation (114°F, 45°C), can be used if agreed upon by the supplier and the purchaser. See ASTM D 4587.
11.10 The cosmetic characteristics of the final coat (gloss, color, gloss and tint retention, etc.) should be agreed upon by the contracting parties and evaluated in accordance with ASTM D 523.
11.11 The testing procedure in ASTM D 1211 is similar to that of a non-ASTM test used by the automotive coating industry and others. Because the equipment and procedure of ASTM D 1211 are more widely known, it is specified for use here. One cycle of the test consists of a period of seven hours at 140°F (60°C) followed by 16 hours at 10°F (-12°C) followed by one hour at room temperature (70°F, 21°C).
11.12 Choice of exposure direction (horizontal, face up—maximum UV light and weathering; horizontal, face down— maximum condensation; South vertical—typical weathering; or South 45°—accelerated natural weathering) and environment shall be made consistent with the weathering/environmental conditions expected at the location of use of the system. If no direction is specified by the purchaser, South 45° shall be used.
11.13 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, have exhibited average bare steel corrosion rates of one to three mils (25 to 76 micrometers) per year based on 12 months of exposure. Test systems used to establish performance requirements were evaluated at these sites, and the sites have been found suitable for the exterior exposure conditions of this specification.
11.14 The procurement documents should establish the responsibility for samples, testing, and any required affidavit certifying full compliance with the specification.
PAINTING SPECIFICATION NO. 24.00 – Latex Painting System for Industrial and Marine Atmospheres, Performance-Based
