1、6-97SSPC-Paint 27November 1, 1982Editorial Revisions November 1, 2004SSPC: The Society for Protective CoatingsPAINT SPECIFICATION NO. 27Basic Zinc Chromate-Vinyl Butyral Wash Primer11. Scope1.1 This specifi cation covers a two-component basic zinc chromate-vinyl butyral wash primer for structural st
2、eel surfaces prior to painting.1.2 It is intended that this coating be used primarily on clean steel free of rust and scale or on clean galvanized metal cleaned according to SSPC-SP 1, “Solvent Cleaning”; but it may be used, when specifi ed, on steel with very slight amounts of rust. It is to be app
3、lied by brush or spray in accordance with SSPC-PA 1, “Shop, Field, and Maintenance Painting of Steel.”2. Description2.1 Basic zinc chromate-vinyl butyral wash primer is a pretreatment for metals which reacts with the metal and at the same time forms a protective vinyl fi lm which contains an inhibi-
4、tive pigment to help prevent rusting. This coating is supplied as two components which are mixed together just prior to use. The base contains an alcohol solution of polyvinyl butyral resin pigmented with basic zinc chromate. The diluent contains an alcohol solution of phosphoric acid which reacts w
5、ith the vinyl resin, the pigment, and the steel. Details of the composition are given in Federal Specifi cation DoD-P-15328.2.2 This primer contains approximately 10% by volume of nonvolatile fi lm-forming solids (pigment and binder). The theoretical spreading rate for a 0.5 mil (13 micrometers) dry
6、 film thickness is 320 square feet/U.S. gallon (7.9 square meters/liter). Actual spreading rates can be signifi cantly lower.3. Referenced Standards3.1 The standards referenced in this specifi cation are listed in Sections 3.4 through 3.7 and form a part of this specifi ca-tion.3.2 The latest issue,
7、 revision, or amendment of the refer-enced standards in effect on the date of invitation to bid shall govern unless otherwise specifi ed.3.3 If there is a confl ict between the requirements of any of the cited reference standards and this specifi cation, the requirements of this specifi cation shall
8、 prevail.3.4 SSPC STANDARDS:SSPC Guide 13 Guide for the Identifi cation and Use of Industrial Coating Material in Computerized Product DatabasesPA 1 Shop, Field, and Maintenance Painting of SteelSP 1 Solvent Cleaning3.5 ASTM INTERNATIONAL STANDARD:D 3925 Practice for Sampling Liquid Paints and Relat
9、ed Pigmented Coatings3.6 FEDERAL STANDARD:DoD-P-15328 Primer (Wash), Pretreatment (Formula No. 117 for Metals)3.7 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARD.Z129.1 Hazardous Industrial ChemicalsPrecautionary Labeling4. Composition4.1 Ingredients, proportions, and analysis shall be as spec
10、ifi ed in Federal Specifi cation DoD-P-15328.5. Properties5.1 The paint shall meet the requirements of Federal Specifi cation DoD-P-15328.6. Labeling6.1 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
11、13.6.3 MARKING OF CONTAINERS: Each container of each component shall be legibly marked with the following information:1 This paint contains chromate pigments. Users are urged to follow all health, safety, and environmental requirements in applying, handling, and disposing of these materials.6-98SSPC
12、-Paint 27November 1, 1982Editorial Revisions November 1, 2004Name: Basic Zinc Chromate-Vinyl Butyral Wash PrimerSpecifi cation: SSPC-Paint 27Component: Lot Number: Stock Number: Date of Manufacture: Quantity of Paint in Container: Information and Warnings as may be required byFederal and State Laws:
13、 Manufacturers Name and Address: 6.3 DIRECTIONS FOR USE: The following directions use shall be supplied with each container of paint:Directions for Use of Basic Zinc Chromate-VinylButyral Wash PrimerThis paint is intended to be used primarily on clean steel free of rust and scale or on clean galvani
14、zed metal; but it may be used, when specifi ed, on steel with very slight amounts of rust bloom.Four volumes of base shall be mixed with one volume of diluent as follows: fi rst, break up the pigment settled in the base with a wooden paddle, mechanical stirrer, or mixer, and mix to distribute the pi
15、gment evenly throughout the base. After the base is thoroughly mixed, slowly pour one volume of the diluent into four volumes of the base with constant agitation. Do not pour off the liquid which has separated from the pigment and then add the diluent to the settled pigment to aid mixing. Material w
16、hich is not mixed properly may gel and be unfi t for use. The base shall be mixed with the diluent in quantities which will be applied within six to eight hours after mixing. Primer that cannot be used within a maximum of eight hours after mixing with diluent shall be discarded and not used. Screen
17、paint before applying.Apply the wash primer by spraying or brushing. Spray-ing is generally the preferred method, but brushing may be desirable over rough or poorly prepared steel. Roller coating may be used only if specifi ed. Paint brushes should be clean and dry, or wetted with alcoholic solvents
18、. When sprayed, the primer must be deposited on the surface wet; if dusting is encountered, move the gun closer to the surface; if already within six inches (15 cm) of the surface, decrease atomizing air pressure or increase the liquid pressure, or add thinner.Where thinning is desired isopropanol (
19、99% grade) or butanol (normal butyl alcohol) or denatured ethanol should be used. At least 25% thinning is usually necessary to get a uniform application. Use denatured ethyl or isopropyl alcohol to clean equipment.Apply to a dried fi lm thickness of 0.3 to 0.5 mils (8 to 13 micrometers) dry or appr
20、oximately 3 to 5 mils (75 to 125 mi-crometers) wet. Note that at this thickness, which should not be exceeded, the base metal will show through the coating as evidenced by uneven coloring. This is the normal appearance; do not attempt to hide the base metal completely.When spot treating, cover only
21、spots free of old paint. Slight overlap of existing paints is generally not harmful provided adherence of the wash primer to the old paint is satisfactory and the old paint is not lifted.The next coat of paint may be applied as soon as the wash primer is dry, usually from one half hour to four hours
22、 later, except when otherwise authorized by the inspector.This wash primer should be applied over clean, dry steel; however, a slightly damp surface may be painted over, provided adequate normal butyl alcohol is used in the thinner. If the surface is excessively wet, the vinyl butyral resin will be
23、thrown out of solution and form a gel, or the dried fi lm will turn white, become brittle, and lack adhesion to the steel.This wash primer is not intended for use as a shop coat for steel, and it should be recoated with the prime coat of paint before exposure, preferably within 24 hours.7. Inspectio
24、n7.1 All materials (coatings) supplied under this specifi ca-tion 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 specifi cation (see Note 9.1). In case
25、of dispute, un-less otherwise specifi ed, 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. 7.2 Samples
26、 of paints may be requested by the purchaser and shall be supplied upon request along with the manufac-turers name and identifi cation 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 sp
27、ecifi ed, the sampling shall be in accordance with ASTM D 3925.8. Disclaimer8.1 While every precaution is taken to ensure that all information furnished in SSPC standards and specifi cations is as accurate, complete, and useful as possible, SSPC cannot assume responsibility nor incur any obligation
28、resulting from the use of any materials, coatings, or methods specifi ed herein, or of the specifi cation or standard itself.8.2 This specifi cation does not attempt to address problems concerning safety associated with its use. The user of this specifi cation, as well as the user of all products or
29、 practices described herein, is responsible for instituting appropriate health and safety practices and for ensuring compliance with all governmental regulations.6-99SSPC-Paint 27November 1, 1982Editorial Revisions November 1, 20049. NotesNotes are not requirements of this specifi cation.9.1 The pro
30、curement documents should establish the responsibility for samples, testing, and any required affi davit certifying full compliance with the specifi cation.9.2 This wash primer is intended for use over clean, dry, descaled steel. It does not work over phosphate treated steel, and should not be used
31、over paint or wetting oils. It must be used on bare metal for best results. If used over mill scale, it may contribute to mill scale lifting.9.3 This wash primer may be used to bond conventional paints to galvanized surfaces or stainless steel. Solvent cleaning of such surfaces, even though apparent
32、ly clean, is advisable before applying the wash primer. Adhesion to some types of white rust preventives on galvanized steel is poor.9.4 Almost all paints will adhere well to this wash primer; exceptions are certain types of vinyl paints and some lacquers.These coatings may require an intermediate or bonding coat. Paints containing alcohol or ketone solvents generally show best bonding.
