The owner must also ensure the paint systems

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quately cover the regulatory requirements that the bidders will be asked to cover by their proposal. The owner must also ensure the paint system(s) specified is compatible with existing coatings, if applicable, and the system(s) is proper for the site environment in which it will be located. EXISTING PAINT TO BE COATED KNOWN INCOMPATIBLE COATINGS SYMPTOM OF INCOMPATIBILITY Zinc Alkyds Blisters or Delaminates Oil/Alkyd Solvent Based Vinyls; Epoxies Softening, Lifting or Shriveling Vinyl Epoxies Softens or Dissolves Coating Table 3 Coating Incompatibility Note: with the proper formulations, even the above incompatibilities may be overcome.
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SYSTEMS PAGE 50 The contractor is responsible for properly preparing the surface, supplying only acceptable materials and trained workers, supplying properly maintained equipment whether the paint is applied in a shop or the field, and full compliance with the regulatory requirements contained in the contract documents. The paint manufacturer is responsible to supply only the level of quality of materials that meet the contract requirements, including ade- quate instructions to the contractor and owner of the environmental and application requirements to safely obtain a long-lasting coating. EVALUATION OF PERFORMANCE REQUIREMENTS FOR COATING SYSTEMS The key to selecting paint is to know the performance criteria. For maintenance paint, whether painting the walls of a home or the I-beams of a bridge, there are test methods available whose results can guide in the selection of the paint. Performance data are available from paint suppliers. A comparison of the different types of paint performance, the cost and the years of service will lead to the best economical decision. During paint development, performance is measured on paint that is applied under standard conditions. For example, laboratory conditions are held closely around 77° Fahrenheit and 50 percent relative humidity. In addi- tion, surface preparation of the substrate, film thickness, spray conditions, etc. can be very carefully controlled. This leads to very reproducible results and the possibilities of good comparisons between generic types of paint and even between formulations within a type of paint. Paint is seldom applied in the field under the same carefully controlled conditions used during laboratory cure and testing. This means that field performance may not duplicate exactly laboratory performance. Although the same performance trends seen in the laboratory between generic types of paint and formulations of the same type usually are seen in the field, most researchers will admit that it is very difficult to predict field life expectan- cies from laboratory data. There are several ways in which performance information can be gathered: ! Case histories ! Outdoor panel exposures ! Accelerated laboratory tests SYSTEM NO. GENERIC COATING TYPE 1 Waterborne Acrylic (3 Coats) 2 Moisture-Cured Urethane (3 Coats) 3 Epoxymastic/Aliphatic Urethane 4 Surface Sealer Epoxy/Urethane/Urethane 5 Surface Sealer Urethane/Urethane/Urethane 6 Low VOC Alkyd Primer (2 Coats) Low VOC Silicone Alkyd Topcoat
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