Three-Coat Latex Painting System

Applying Three-Coat Latex Painting System

PAINTING SYSTEM NO. 18.01 – Three-Coat Latex Painting System

1. Scope

1.1 This specification covers a complete latex painting system for structural steel.

1.2 This painting system is suitable for use on parts or structures exposed in Environmental Zones 1A (interior, normally dry), and 1B (exterior, normally dry), and high humidity or mild chemical atmospheres.

1.3 The finish paint is semi-gloss, chalk resistant, and allows for a choice of colors.

2. Description

2.1 This painting system consists of surface preparation by commercial blast, two coats of latex primer, and one latex semi-gloss finish coat.

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 AND JOINT STANDARDS:

PA 1  Shop, Field, and Maintenance Painting of Steel
PA 2  Measurement of Dry Coating Thickness With Magnetic Gages
PA Guide 4  Guide to Maintenance Repainting with Oil Base
Paint 23     Latex Primer for Steel Surfaces
Paint 24     Latex Semigloss Exterior Topcoat
SP 5/NACE No. 1  White Metal Blast Cleaning
SP 6/NACE No. 3  Commercial Blast Cleaning
SP 8  Pickling
SP 10/NACE No. 2  Near-White Blast Cleaning

3.4 AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) STANDARDS:

D 3925     Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings

4. Surface Preparation

4.1 SSPC-SP 6, “Commercial Blast Cleaning,” or SSPC­SP 8, “Pickling.” If specified in the procurement documents, a better degree of cleaning shall be substituted (SSPC-SP 5, “White Metal Blast Cleaning,” or SSPC-SP 10, “Near-White Blast Cleaning”).

5. Paints

5.1 PRIMER: SSPC-Paint 23, “Latex Primer for Steel Surfaces.”

5.2 INTERMEDIATE: SSPC-Paint 23, “Latex Primer for Steel Surfaces,” tinted to a color contrasting with the primer and the finish coat.

5.3 FINISH COAT: SSPC-Paint 24, “Latex Semi-Gloss Exterior Topcoat.” The color must be specified.

6. Paint Application

6.1 PAINT APPLICATION: Follow the requirements SSPC­PA 1, “Shop, Field, and Maintenance Painting of Steel.”

6.2 TOUCH-UP PAINTING: In accordance with specifica­tion SSPC-PA 1, “Shop, Field, and Maintenance Painting of Steel” and in particular with the section thereof entitled “Field Painting.”

6.3 MAINTENANCE PAINTING: For maintenance painting procedures, see SSPC-PA Guide 4, “Guide to Maintenance Repainting with Oil Base or Alkyd Painting Systems.”

6.4 NUMBER OF COATS: Minimum of three.

6.5 DRY FILM THICKNESS OF PAINT SYSTEM: Not less than the following as measured in accordance with SSPC­PA 2, “Measurement of Dry Coating Thickness with

Magnetic Gages”: primer 64 micrometers (2.5 mils); intermedi­ate coat 50 micrometers (2.0 mils); finish coat 38 micrometers (1.5 mils); for the three-coat painting system 150 micrometers (6.0 mils).

7. Inspection

7.1 All work and materials supplied under this specifica­tion are subject to timely inspection by the purchaser or his authorized representative. The contractor shall correct such work or replace such material as is found defective under this specification (See Note 9.1.). 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.

7.2 Samples of paints under this painting system may be requested by the purchaser and shall be supplied upon request along with the manufacturerʼs 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. Disclaimer

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 specifi ed 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 insuring compliance with all governmental regulations.

9. Notes

Notes are not a requirement 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 It is not recommended to expose steel to the weather with less than two coats of water borne coating. Therefore, the intermediate coat should be applied before any exposure and the finish coat within three months for maximum performance of this painting system.