Silicone Alkyd Paint Types I and II
PAINT SPECIFICATION NO. 21 – White or Colored Silicone Alkyd Paint Type I, High Gloss Type II, Medium Gloss
1.1 This speciﬁcation covers white or colored silicone alkyd paint suitable for the ﬁnish coat on primed structural steel.
1.2 INTENDED USE: The speciﬁcation covers a high grade air dry silicone alkyd type copolymer gloss and medium gloss enamels intended for use on primed metal but particularly on smooth exterior metal. It is highly weather resistant and is characterized by excellent color and gloss retention. This coating is primarily intended for spray application, but may also be applied by brush or roller. It is to be applied in accordance with SSPC-PA 1, “Shop, Field and Maintenance Painting of Steel.”
1.3 The color of the enamel speciﬁed in the procurement documents shall match that of the standard color chip in FEDSTD 595 or other colors agreed upon.
2.1 Two types of paint are available under this speciﬁcation: Type I covers high gloss and Type II covers medium gloss silicone alkyd white or colored paints. Twelve colors are described under each type in this speciﬁcation (see Tables 1 and 2).
2.2 This paint contains a minimum of 60 to 67% by volume of nonvolatile ﬁlm-forming solids (pigment and binder). The minimum theoretical spreading rate for a 1.5 mil (38 micrometers) dry ﬁlm thickness is 640 to 720 square feet/U.S. gallon (15.7 to 17.6 square meters/liter). Actual spreading rates can be signiﬁcantly lower.
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 referenced standards and this speciﬁcation, the requirements of this speciﬁcation shall prevail.
3.3 SSPC 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
3.4 ASTM INTERNATIONAL STANDARDS:
D 93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D 95 Test Method for Water in Petroleum Products and Bituminous Materials by Distillation
D 185 Test Method for Coarse Particles in Pigments, Pastes, and Paints
D 235 Speciﬁcation for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)
D 476 Classiﬁcation for Dry Pigmentary Titanium Dioxide Products
D 523 Test Method for Specular Gloss
D 562 Test Method for Consistency of Paints Measuring Krebs Unit (KU) Viscosity Using a Stormer-type Viscometer
D 600 Speciﬁcation for Liquid Paint Dryers
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 1306 Test Method for Phthalic Anhydride Content of Alkyd Resins and Esters Containing Other Dibasic Acids (Gravimetric)
D 1398 Test Method for Fatty Acid Content of Alkyd Resins and Alkyd Resin Solutions
D 1640 Test Methods for Drying, Curing, or Film Formation of Organic Coatings at Room Temperature
D 1729 Practice for Visual Evaluation of Color Differences of Diffusely-Illuminated Opaque Materials
D 1849 Test Method for Package Stability of Paint
D 2244 Test Method for Calculation of Color Differences from Instrumentally Measured Color Coordinates
D 2369 Test Method for Volatile Content of Coatings
D 2371 Test Method for Pigment Content of Solvent Reducible Paints
D 2698 Test Method for the Determination of Pigment Content of Solvent Reducible Paints by High Speed Centrifuging
D 2800 Test Method for Preparation of Methyl Esters from Oils for Determination of Fatty Acid Composition by Gas-Liquid Chromatography
D 2805 Test Method for Hiding Power of Paints by Reﬂectometry
D 3335 Test Method for Low Concentrations of Lead, Cadmium, and Cobalt in Paint by Atomic Absorption Spectroscopy
D 5486 Speciﬁcation for Pressure-Sensitive Tape for Packaging, Box Closure, and Sealing
E 97 (Withdrawn, replaced by E 1347) Test Method for Directional Reﬂectance Factor, 45°-0° of Opaque Specimens by Broad-Band Filter Reﬂectometry
3.5 FEDERAL STANDARDS:
TT-E-1593 (canceled) Enamel, Silicone Alkyd Copolymer, Gloss (for Exterior and Interior Use)
FED-STD-141: Paint, Varnish, Lacquer, and Related Materials: Methods of Inspection, Sampling, and Testing
Section 9 Routine and Referee Testing Conditions
Method 2011 Preparation of Steel Panels
Method 3021.1 (canceled) Condition in Container
Method 4061 Skinning (Partially Filled Container)
Method 4092 (canceled) Coarse Particles and Skins in Synthetic Vehicle Enamels, Lacquers, and Dopes (use ASTM D 185)
Method 4203.2 Reducibility and Dilution Stability
Method 4321 Brushing Properties
Method 4331 Spraying Properties
Method 6221 (canceled) Flexibility
Method 7014 (canceled) Analysis of Unsaponiﬁable Matter, Oil Acids, and Phthalic Anhydride in Alkyd Vehicles
FED-STD-595: Colors Used in Government Procurement
3.6 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD:
Z129.1 Hazardous Industrial Chemicals – Precautionary Labeling
4.1 The pigments listed in Table 1 (or Type I) or Table 2 (or Type II), or any combination thereof, shall make up the basic pigmentation for the color speciﬁed. Extender pigments, shading pigments, and titanium dioxide conforming to ASTM D 476, Type IV, may be used when necessary to match the color speciﬁed, provided the enamel complies with the requirements of this speciﬁcation.
4.2 The vehicle shall consist of silicone-modiﬁed medium oil soya alkyd copolymer of the air-drying type, together with suitable thinners, driers, anti-skinning agents, wetting agents, dispersing agents, and stabilizers combined, producing a material conforming to all requirements speciﬁed herein. The silicone intermediate used in the preparation of the copolymerized resin shall be hydroxy functional. The vehicle shall conform to the composition (analysis) requirements of Table 3.
4.3 SOLVENT: Shall be mineral spirits conforming to ASTM D 235.
4.4 DRIERS: Shall conform to ASTM D 600.
4.5 The paint shall conform to the composition (analysis) requirements of Table 4 (or Type I) or Table 5 (or Type II).
5.1 The alkyd paint shall meet the requirements of Table 6 and Sections 5.2 through 5.12.
5.2 ODOR: Shall be normal for the materials permitted (ASTM D 1296). The odor of the wet enamel and of the ﬁlm at any interval of drying shall not be obnoxious or objectionable.
5.3 COLOR: Draw down a coat of enamel on a white opaque glass panel using a doctor blade with a 6 mil (150 micrometer) gap clearance designed to deposit a wet ﬁlm thickness of approximately 3 mils (76 micrometers). After 48 hours drying, at 70 to 75 °F (21 to 24 °C) and 50% relative humidity, compare the dried ﬁlm with the standard chip (FED-STD-595) or other color agreed upon in accordance with ASTM D 1729 for compliance. If doubt exists as to the color match, an instrumental referee method may be used (ASTM D 2244).
5.4 DILUTION STABILITY: There shall be no evidence of incompatibility of any of the ingredients of the paint when one volume of the paint is slowly mixed with one volume of the mineral spirits (FED-STD-141, Method 4203). However, slight pigment settling shall be permitted.
5.5 BRUSHING PROPERTIES: The enamel, as packaged, shall be easily applied when tested in accordance with FED-STD-141, Method 4321. The enamel shall dry to a smooth, uniform ﬁlm, free from seeds, runs, sags, or streaks. The dried ﬁlm shall show no discernible brush marks.
5.6 SPRAYING PROPERTIES: Prepare a steel panel in accordance with FED-STD-141, Method 2011 using the petroleum napthaethylene glycol monoethyl ether mixture. Spray apply the enamel to this panel to a dry ﬁlm thickness of 0.9 to 1.1 mils (23 to 28 micrometers). The enamel shall be easily applied when tested in accordance with FED-STD-141, Method 4331. The enamel shall show no running, sagging, or streaking. The air dried ﬁlm shall show no seeding, dusting, ﬂoating, fogging, mottling, hazing, excessive orange peel, or other ﬁlm defects.
5.7 CONDITION IN CONTAINER: Determine package condition of the enamel in accordance with FED-STD-141, Method 3011. The enamel shall be free of grit, seeds, skins, lumps, thickening, or livering and shall show no more pigment settling or caking that can be readily reincorporated to a smooth homogeneous state. Reseal and then agitate the can for three minutes on a paint shaker. On reexamination of the contents, the disclosure of gel bodies, undispersed pigment, or unsatisfactory settling properties is cause for rejection.
5.8 STORAGE STABILITY, PARTIALLY FULL CONTAINER: Determine skinning after 48 hours in accordance with FED-STD-141, Method 3021 except use 3/4 ﬁlled, 1/2 pint (250 ml) multiple friction top can. The enamel shall show no skinning. Reseal and store for seven days at 140 °F (60 °C) and observe. The enamel shall show no livering, curdling, hard caking, or gummy sediment. It shall mix readily to a smooth homogeneous state.
5.9 STORAGE STABILITY, FULL CONTAINER: Determine the storage stability of the package enamel in accordance with ASTM D 1849 using a standard quart can allowed to stand undisturbed for 12 months. The enamel shall show no skinning, livering, curdling, hard-dry caking, or tough gummy sediment. Evaluate pigment settling or caking, but agitate the can for ﬁve minutes on the paint shaker prior to examination. The enamel shall mix readily to a smooth homogeneous state and must be usable. The consistency of the enamel after storage shall be 60 to 82 Krebs units (ASTM D 562).
5.10 ADHESION: Use the panel prepared in 5.6 by air drying for 18 hours, then baking for 2 hours at 220 ± 4 °F (105 ± 2 °C). Condition the panel for one hour under referee testing conditions (Section 9 of FED-STD-141), then score a line through to the metal across the width of the ﬁlm using a sharp pointed knife. The ﬁlm shall then be taped perpendicular to and across the score line with waterproof, pressure sensitive tape, 3/4 inch (2 cm) wide, conforming to ASTM D 5486. Press the tape in ﬁrm contact with pressure. Allow approximately 10 seconds for the test area to return to room temperature. Grasp the free end of the tape and at a rapid speed strip it from the ﬁlm by pulling back from the panel at an approximately 180 degree angle. The enamel shall show no removal of the ﬁlm and weigh to the nearest 0.1 mg. Weigh one of the 60 mm aluminum dishes with fourth-decimal place accuracy. Transfer a small sample that does not exceed 0.3 grams to the dish, and determine its exact weight by loss of weight of the bottle. Dissolve the sample in 2 ml of ACS reagent grade toluene and dry in a gravity convection oven at 105 ± 2°C for three hours. After cooling for 30 minutes, weigh the dish to the nearest 0.1 mg. From the weight of the residue in the dish and the weight of the sample taken, calculate the percent vehicle solids or loosening beyond 1/16 inch (2 mm) on either side of the score line.
5.11 FLEXIBILITY: Determine ﬂexibility in accordance with FED-STD-141, Method 6221. Apply a 2 inch (5 cm) wide ﬁlm of enamel on a smooth ﬁnish steel panel, prepared in accordance with FED-STD-141, Method 2011, using the petroleum naphtha ethylene glycol monoethyl ether mixture with a suitable ﬁlm applicator that will give a dry ﬁlm thickness of 0.9 to 1.1 mils (28 to 28 micrometers). The panel shall be prepared for new cold rolled rust-free carbon steel 10 ± 1 mils (250 ± 25 micrometers) thick with a Rockwell 15-T maximum hardness of 82 and a ﬁnish with surface toughness of 8 to 12 microinches (0.2 to 0.3 micrometers). Air dry in a horizontal position for 18 hours, and then bake for 168 hours at 220 ± 4 °F (105 ± 2 °C). Condition the panel for 1/2 hour under standard testing conditions (see Section 9 of FED-STD-141). Bend over a 1/4 inch (6 mm) mandrel. Examine the coating for cracks over the area of the bend in a strong light at seven diameters magniﬁcation. The enamel shall withstand the bending without cracking or ﬂaking.
5.12 HIDING POWER (CONTRAST RATIO): Determine the hiding power in accordance with ASTM D 2805. Draw down a ﬁlm using an applicator that will deposit a dry ﬁlm of 1 mil (25 micrometers) maximum thickness. Air dry for 72 hours, measure the thickness of the dry ﬁlm, then measure the reﬂectance. Calculate the contrast ratio. A dry ﬁlm thickness of 1 mil (25 micrometers) maximum of white enamel (minimum reﬂectance 84%) shall give a dry ﬁlm contrast ratio of 0.95. The minimum dry ﬁlm contrast ratio for tints applied at the same wet ﬁlm thickness in terms of apparent reﬂectivity shall be speciﬁed in Table 7.
6.1 Labeling shall conform to ANSI Z129.1.
6.2 Technical data shall be provided for at least all data elements categorized as “essential” in SSPC-Guide 13.
6.3 MARKING OF CONTAINERS: Each container shall be legibly marked with the following information:
Name: White or Colored Silicone Alkyd Paint
Speciﬁcation: SSPC-Paint 21, Type
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:
6.4 DIRECTIONS FOR USE: The following directions for use shall be supplied with each container of paint:
Directions for Use of White or Colored Silicone Alkyd Paint
This paint is intended for use as a ﬁnish coat over a rust inhibitive primer (or other suitable primers) and an intermediate coat on structural steel. Before applying, remove all moisture, oil, grease, dirt, and loose or non-adhering paint. Sound old coatings that are compatible with this silicone alkyd paint may remain, but damaged areas or areas of poor adhesion must be spot-cleaned and spot-primed.
Mix paint thoroughly before use. If simple stirring is inadequate, pour off most of the liquid into a clean container. 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 the container for unmixed pigment. Screen paint before applying.
Thin paint only if necessary, using only mineral spirits. For brush application under normal conditions, no thinning should be necessary. For spray applications, add up to one pint of thinner per gallon (130 ml/L) of unthinned paint when necessary.
Apply by brush or spray to the speciﬁed ﬁlm thickness or, if none is speciﬁed, to at least 1.5 mils (38 micrometers) dry or approximately 2.5 mils (64 micrometers) wet. The surface to be painted shall be dry; the surface temperature shall be at least 5 °F (3 °C) above the dew point; and the temperature of the air shall be over 40 °F (4 °C). Do not paint outdoors in rainy weather or if freezing temperatures are expected before the paint dries. Allow paint at least 24 hours drying time in good weather before recoating.
7.1 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 9.1). In case of dispute, unless otherwise speciﬁed, the arbitration or settlement procedures established in the procurement documents shall be followed. If no arbitration procedure is established, then a procedure mutually agreeable to the purchaser and material supplier shall be used
7.2 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.
7.3 Unless otherwise speciﬁed, the sampling shall be in accordance with ASTM D 3925.
8.1 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.
8.2 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.
9.1 The procurement documents should establish the responsibility for samples, testing, and any required afﬁdavit certifying full compliance with the speciﬁcation.
9.2 ASTM and Federal Standard Test Methods listed as “canceled” or “withdrawn” are no longer maintained, but still available as historical documents.
Paint Specification No. 21 – White or Colored Silicone Alkyd Paint Type I, High Gloss Type II, Medium Gloss