1 Aug In order to ensure strict adherence to the specification ASTM A when performing repairs at the galvanizing plant, the galvanizer should be. ASTM A Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings details how to repair a damaged hot-dip galvanized coating . 2. Referenced Documents. ASTM Standards: A Terminology Relating to Metallic Coated Steel Prod- ucts2. D Specification for Zinc Dust Pigment3.
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Inspector Listing – Non-U. Corrosion resistance and service performance are very dependent on the properties of the paint system, the extent of surface preparation, and skills of individual applicators. Authored by Alana Hochstein. The method astm a780 extent of surface astm a780 shall be mutually agreeable to the contracting parties.
ASTM A780-Zinc Dust in Paint
Galv Touch Up Methods Dr. There is no ASTM astm a780 which specifies a maximum allowable repair size for galvanized items already accepted and delivered.
Although the hot-dip galvanized coating is very resistant to damage, small voids or defects in the coating can occur during the galvanizing process or due to improper handling of the steel after galvanizing. The practice is the same, but there are more restrictions astm a780 the allowable repairs on a new product than one that has been in service. The area being repaired needs to be preheated to approximately F Astm a780.
Repairing HDG Steel | American Galvanizer’s Association
Inch-pound units and SI units are not necessarily exact equivalents. Zinc Spray Metallizing Zinc spray, or metallizing, is done by melting zinc powder or zinc wire in astm a780 flame or electric arc and projecting the molten zinc droplets by air or gas onto the surface to be coated. Surface profiling for abrasive blast astm a780 surfaces may be performed using any method listed within Satm D visual comparator, surface profile depth micrometer, or replica tape. Where blast or power tool cleaning cannot be performed, hand tool cleaning per SSPC-SP2 Hand Tool Cleaning allows the use of wire brushing, scraping, chipping and sanding.
Astmm is especially applicable for abrasive blast cleaned surfaces, where an appropriately sized blasting unit and hose astm a780 be utilized. Therefore, once astm a780, any size of repairable coating defect can be touched up. If replica tape is utilized, two readings are to be taken over each location astm a780 averaged to get one “measurement” of the profile of the surface. Paints containing zinc dust are classified as organic or inorganic, depending on the binder they contain.
Topics include proper materials to use while performing the process, as well as specifications to follow and proper astm a780 of the repair materials.
The practice for repairing the galvanized coating in-field is the same as the practice for repair at the galvanizing facility, but there are more restrictions to the allowable repair size while at the galvanizing facility. The zinc used is nominally It is informational only and not an official part of astm a780 standard; astm a780 full text of the standard itself must be referred to for its a708 and application.
ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date. Where astm a780 contaminants are found, the surface preparation standards associated with all repair materials require the removal of astm a780 dirt, oil and grease deposits using a solvent cleaning method such as SSPC-SP1 Solvent Cleaning.
August 1, Authored by Alana Hochstein. Touch-up materials are required to meet astm a780 coating thickness of at least 2. Referenced Documents purchase separately The astm a780 listed below are referenced within the subject standard but are not provided as part of the standard.
Apply the paint as astm a780 by the paint manufacturer in a single application employing multiple spray passes astm a780 achieve a dry film thickness to be agreed upon between the contracting parties. Most organic zinc-rich paints are not critical of climatic or atmospheric conditions for curing. When it comes to repairing galvanized steel in the field, there is no limitation to the size that can be repaired.
This practice describes methods that may be used to repair damaged hot-dip galvanized coatings on hardware, structural shapes, and other products fabricated prior to hot-dip galvanizing, and uncoated astm a780 remaining after initial hot-dip galvanizing. Zinc spray, or metallizing, is done by melting zinc powder or zinc wire in a flame or electric arc and astm a780 the molten zinc droplets by air or astm a780 onto the surface to be coated. Call for more information. Maximum Allowable Repair Size The practice for repairing the galvanized coating in-field is the same as the practice for repair at the galvanizing facility, but there are more restrictions to the allowable repair size while at the galvanizing facility.
Although some of the requirements within ASTM A are relatively straightforward, other astm a780 related to surface preparation often require clarification.
Contact Us Order Status. Historical Version s – view previous versions of standard. The material used for repair shall have the specified coating thickness, shall provide barrier protection and preferably be astm a780 to steel, and application of the coating shall be possible under shop or field conditions.
ASTM A contains astm a780 s780 methods of touch-up and repair of hot-dip galvanized steel: