1、6-135SSPC-Paint 34May 1, 1996Editorial Revisions November 1, 2004SSPC: The Society for Protective CoatingsPAINT SPECIFICATION NO. 34Water-Borne Epoxy Topcoat for Steel Surfaces1. Scope1.1 This specifi cation covers an ambient-cured, two-component water-borne epoxy coating that is intended for use as
2、 a fi nish coat in multicoat water-borne epoxy systems for steel.1.2 Topcoats are categorized according to performance levels (Sections 2.3, 6, and 7). 1.3 Topcoats meeting this specifi cation, when used with an appropriate primer, are suitable for exposures in Environmental Zones 1A (interior, norm
3、ally 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 specifi ed topcoat is intended for application by brush, spray, or roller over primed surfaces prepared in accordance with the manufacturers re
4、commendations. It is suitable for use as a water-borne epoxy topcoat in a two-coat system or as an intermediate coat and topcoat in a three-coat system, to be applied in accordance with the manufacturers recommendations.2. Description2.1 COMPOSITION2.1.1 The topcoat specifi ed is based on a reactive
5、 oxirane (epoxy) functional resin with amine or acid functional curing agents.2.1.2 The major volatile component by weight is water. Refer to ASTM D 3792 or ASTM D 4017 for determination of the water content of paints.2.2 VOLATILE ORGANIC COMPOUND (VOC) CONTENT: Consult applicable government regulat
6、ions to determine maximum allowable VOC content and the proper VOC test method for a particular application. The supplier should provide VOC information on the coating as supplied (in the container) and as applied (in the fi eld after recommended thinning).2.3 PERFORMANCE LEVEL: The fi nish coat sha
7、ll be classifi ed according to exposure performance achieved as follows, based on testing of primed systems as specifi ed. Level 1 Accelerated Testing (Section 6) Level 2 12-Month Exterior Exposure (Section 7.2)Level 3 36-Month Exterior Exposure (Section 7.3)2.3.1 If no performance level is specifi
8、ed, Level 2 is assumed.3. Referenced Standards3.1 The latest issue, revision, or amendment of the referenced standards in effect on the date of invitation to bid shall govern unless otherwise specifi ed.3.2 If there is a confl ict between the requirements of any of the cited reference standards and
9、this specifi cation, the requirements of this specifi cation shall prevail.3.3 SSPC SPECIFICATIONS:SSPC Guide 13 Guide for the Identifi cation and Use of Industrial Coating Material in Computerized Product DatabasesPaint 28 Water-Borne Epoxy Primer for Steel SurfacesPA 1 Shop, Field, and Maintenance
10、 Painting of SteelPA 2 Measurement of Dry Coating Thick-ness with Magnetic GagesSP 10 Near-White Blast CleaningVIS 2 Guide and Reference Photographs for Evaluating Degree of Rusting on Painted Steel Surfaces3.4 ASTM INTERNATIONAL STANDARDS:A 36 Specifi cation for Carbon Structural SteelB 117 Practic
11、e for Operating Salt Spray (Fog) ApparatusD 523 Test Method for Specular GlossD 562 Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using a Stormer-type ViscometerD 609 Practice for Preparation of Cold-Rolled Steel Panels for Testing Paint, Varnish, Conversion Coatings, and
12、 Related Coating ProductsD 610 Test Method for Evaluating Degree of Rusting on Painted Steel SurfacesD 714 Test Method for Evaluating Degree of Blis-tering of PaintsD 823 Practices for Producing FIlms of Uniform Thickness of Paint, Varnish, and Related Products on Test PanelsD 1200 Test Method for V
13、iscosity by Ford Viscosity Cup6-136SSPC-Paint 34May 1, 1996Editorial Revisions November 1, 2004D 1475 Test Method for Density of Liquid Coatings, Inks, and Related ProductsD 1654 Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive EnvironmentsD 2243 Test Method for Freez
14、e-Thaw Resistance of Water-Borne CoatingsD 2244 Test Method for Calculation of Color Differ-ences from Instrumentally Measured Color CoordinatesD 2369 Test Method for Volatile Content of CoatingsD 2574 Test Method for Resistance of Emulsion Paints in the Container to Attack by Micro-organismsD 3359
15、Test Methods for Measuring Adhesion by Tape TestD 3363 Test Method for Film Hardness by Pencil TestD 3792 Test Method for Water Content of Water-Reducible Paints by Direct Injection into a Gas ChromatographD 3924 Specifi cation for Standard Environment for Conditioning and Testing Paint, Varnish, La
16、cquer, and Related MaterialsD 3925 Practice for Sampling Liquid Paints and Related Pigmented CoatingsD 3960 Practice for Volatile Organic Compound (VOC) Content of Paints and Related CoatingsD 4017 Test Method for Water in Paints and Paint Materials by Karl Fischer MethodD 4060 Test Method for Abras
17、ion Resistance of Organic Coatings by the Taber AbraserD 4417 Test Methods for Field Measurement of Surface Profi le of Blast Cleaned SteelD 4585 Practice for Testing the Water Resistance of Coatings Using Controlled CondensationG 92 Practice for Characterization of Atmospheric Test Sites3.5 AMERICA
18、N NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD: Z129.1 Hazardous Industrial Chemicals Precautionary Labeling3.6 NACE INTERNATIONAL STANDARD:RP 0287 Field Measurement of Surface Profi le of Abrasive Blast Cleaned Surfaces Using Replica Tape3.7 U.S. ENVIRONMENTAL PROTECTION AGENCY:40 CFR Chapter 1, Pa
19、rt 60, Appendix A, Method 24Determination of Volatile Matter Content, Density, Volume Solids and Weight Solids of Surface Coatings4. Composition4.1 The manufacturer is given latitude in the selection of materials, provided the topcoat system meets the require-ments of the specifi cation. Materials s
20、hall be those used in good commercial practice and entirely suitable for the purpose intended under normal conditions.4.2 The coating shall comply with applicable state and local VOC regulations as measured by EPA Method 24, ASTM D 3960, or other required methods. If no method is specifi ed, use EPA
21、 Method 24. The supplier should provide information on the coating as supplied in the container and as thinned for application if VOC is to be added in thinning.5. Standard Testing Conditions5.1 The standard testing conditions shall be in accor-dance with the standard atmosphere in ASTM D 3924, unle
22、ss indicated otherwise. Standard temperature shall be 23 2 C (73.5 3.5F), and standard relative humidity 50 5%.5.2 The standard substrate shall be 3.2 mm (1/8 in.) thick ASTM A 36 hot rolled steel abrasive blasted in accordance with SSPC-SP 10 to a profi le of 50 13 micrometers (2.0 0.5 mils) unless
23、 indicated otherwise. Measure blast profi le in accordance with ASTM D 4417 or NACE RP0287. Sealed and primed chart paper may be used to perform the fi lm irregularity test discussed in Section 6.10.5.3 The substrate shall be primed with a compatible water-borne epoxy primer, as defi ned in SSPC-Pai
24、nt 28, Section 5.3.5.4 The topcoat shall be applied following the manu-facturers recommendations for cure times and method of application.6. Laboratory Performance Testing Requirements6.1 For Level 1 (Accelerated Testing), the coating shall meet the requirements of Sections 6.2 through 6.13. For Lev
25、el 2 and Level 3 (Exterior Exposure), the coating shall meet the requirements of Section 7 in addition to the requirements in Section 6.6.2 RESISTANCE TO MICROORGANISMS IN CONTAINER: The coating shall be resistant to attack by micro-organisms when tested in accordance with ASTM D 2574.6.3 FREEZE-THA
26、W RESISTANCE: Test each of the components separately in accordance with ASTM D 2243. At the end of three cycles there shall be no gelling, coagulation, lumps, coarse particles, or viscosity change in excess of 10 Krebs Units per ASTM D 562.6-137SSPC-Paint 34May 1, 1996Editorial Revisions November 1,
27、 20046.4 PACKAGE STABILITY: Perform the following tests: Place each component in an appropriate closed container (i.e., a lined metal or plastic can) in an oven for one month at 52 1C (125 2F). There shall be no viscosity change in excess of 10 Krebs Units when tested in accordance with ASTM D 562.
28、The cured fi lm shall produce a uniform appearance when applied at recommended fi lm thicknesses.6.5 MECHANICAL STABILITY: Test each component separately by fi lling a one-quart friction top can three-quarters full and closing the can tightly. Rotate on a jar roller for one week at 120-170 rpm. Ther
29、e shall be no indication of separa-tion, coagulation, or changes in viscosity greater than 10 Krebs Units (per 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 pot life of mix
30、ed components of water-borne epoxies cannot be determined simply by measuring changes in viscosity. Thoroughly mix together both components of the coating to yield one quart of mixed material. Allow this mixture to stand at the standard conditions specifi ed in Section 5.1 for the pot life specifi e
31、d by the manufacturer. At the end of this time period, the mixed coating shall show no evidence of gelation and must meet the requirements of Sections 6.7 through 6.13. The cured fi lm shall show no signifi cant change in color or gloss as measured by ASTM D 2244 and D 523, respectively. These metho
32、ds contain defi nitions of the degree of difference between original color or gloss and fi nal color or gloss deemed to be signifi cant by visual observation.6.7 LABORATORY APPLICATION PROPERTIES: Thoroughly mix together both components of the coating. Allow the mixed material to stand for the manuf
33、acturers specifi ed induction time (if any). Apply the coating in accordance with the manufacturers recommendations to a primed, vertical steel substrate under the standard conditions specifi ed in Sections 5.1 through 5.4. Allow the coating to dry in a well-ventilated room or chamber free from draf
34、ts and dust in diffuse light. There shall be no runs, sags, streaks, laps, pinholing, or cratering.6.8 ADHESION: Apply one coat of the coating to a primed panel prepared as specifi ed in Section 5.2. Condition the panel for seven days at standard temperature and humidity (Section 5.1). Evaluate adhe
35、sion in accordance with ASTM D 3359, Method B, using one mm spacing. A rating of 5B is required.6.9 RECOAT TESTS: Apply a second coat of topcoat to a panel prepared as defi ned in Section 6.7, following the manufacturers recommendations. There shall be no picking up or rolling up of the previous coa
36、t(s) during application. After 24 hours, the system should appear smooth and uniform.6.10 FILM IRREGULARITY: Apply one coat of the topcoat by the drawdown method to a 10 x 20 cm (4 x 8 in) primed panel, as prepared in Section 5.2, to produce the manufacturers recommended DFT. Sealed and primed chart
37、 paper may also be used as a substrate for this test. Allow to dry for 24 hours under the standard conditions specifi ed in Section 5.1. There shall be no mud-cracking, alligatoring, or other fi lm irregularities noted upon examination.6.11 RUST AND BLISTER RESISTANCE: 6.11.1 Sample Preparation: Spr
38、ay apply coat(s), per the manufacturers recommendation, to four primed panels prepared in accordance with the standard testing conditions specifi ed in Sections 5.1 through 5.4. Allow the system to dry for up to 14 days. Seal all edges and the back side of each panel with a coating that will provide
39、 the necessary protec-tion to these surfaces. Scribe a fi ve cm (two inch) vertical line through the lower middle portion of the panels to expose the underlying metal before testing. The conditions of making the scribe shall conform to ASTM D 1654.6.11.2 Salt Spray Test: Expose duplicate panels in t
40、he salt fog cabinet for 800 hours according to ASTM B 117. At the end of the 800 hours, immediately examine the panels for rusting, blistering, and creepage. The rusting shall not exceed 8 according to SSPC-VIS 2 or ASTM D 610. The blistering shall not exceed 8F according to ASTM D 714. Check creepa
41、ge from the scribe according to ASTM D 1654, Procedure A. A minimum rating of 7 (1.6 mm 1/16 in. or less) is required. After examining the panels, immediately remove the coating fi lm with a suitable organic solvent as recommended by the manufac-turer. If scraping is necessary to remove the coating
42、fi lm, do so using a piece of soft wood such as a tongue depressor. Do not use a metal spatula or a razor blade. Examine the bare steel substrate. Rusting shall not exceed 8 as judged by the criteria listed above, and rust creep shall not exceed 3.2 mm (1/8 inch) from the center of the scribe.6.11.3
43、 Condensation: Expose the other pair of duplicate panels in a Cleveland Condensing Cabinet for 750 hours at 38C (100F) according to ASTM D 4585. At the end of 750 hours, immediately examine the panels for rusting, blistering, and creepage. The rusting shall not exceed 8 according to SSPC-VIS 2 or AS
44、TM D 610. The blistering shall not exceed 8F according to ASTM D 714. Check creepage from the scribe according to ASTM D 1654, Procedure A. A minimum rating of 7 (1.6 mm 1/16 inch or less) is required. After examining the panels, immediately remove the coating fi lm, using a suit-able organic solven
45、t as recommended by the manufacturer. If scraping is necessary, do so using a piece of soft wood such as a tongue depressor. Do not use a metal spatula or a razor blade. Examine the bare steel substrate. Rusting shall not exceed 8 as judged by the criteria listed above, and rust creep shall not exce
46、ed 3.2 mm (1/8 in.) from the center of the scribe.6-138SSPC-Paint 34May 1, 1996Editorial Revisions November 1, 20046.12 ABRASION RESISTANCE: Apply two coats of the topcoat to three primed steel panels meeting the size require-ments noted in Section 6.1 of ASTM D 4060. Allow the panels to dry for up
47、to 14 days according to the standard testing condi-tions specifi ed in Sections 5.1 through 5.4. An average weight loss of no more than 140 mg is required when tested according to ASTM D 4060 with CS17 wheels for 1000 cycles.6.13 EARLY WATER RESISTANCE: Apply one coat of the topcoat in accordance wi
48、th the standard testing condi-tions specifi ed in Sections 5.1 through 5.3 within 24 hours after priming. After six hours, immerse one-half of the panel in distilled water for fi ve minutes. Remove and allow the system to condition for 10 minutes at standard temperature (see Section 5.1). The expose
49、d section of the panel shall have the same hardness, gloss, and color as the unexposed section when checked according to ASTM D 3363, D 523, and D 2244, respectively.7. Exterior Performance Requirements7.1 Two sets of triplicate panels shall be prepared as specifi ed in Section 6.11.1.7.2 LEVEL 2 EXTERIOR EXPOSURE: Triplicate test specimens shall be exposed for a minimum of 12 months on a test fence at an industrial or marine exposure site having a minimum annual mean precipitation of 635 mm (25 in.) per year. Other criteria for classifying the environme
