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. ASTM Designation: A (American Standard Testing Method). Standard Practice for Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings.
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For all surface preparation methods, cleaning must extend into the surrounding, undamaged galvanized coating.
Historical Version s – view previous versions of standard. Always check for visible contaminants on the surface of the repair area just prior to mechanical cleaning.
Finally, a visual inspection to confirm the level of cleanliness must be carried out to ensure the standard is met.
Repairing HDG Steel
Zinc-rich paint is applied to a clean, dry steel surface by either a brush or spray. Effective May 1st Where such contaminants are found, the surface preparation standards associated with all repair materials require aastm removal of visible dirt, oil and grease deposits using a solvent cleaning method such as SSPC-SP1 Solvent Cleaning.
Inspector Listing – Non-U. The videos provide highly beneficial visual aids to those needing assistance with touch-up and repair, whether in the plant or the field.
Ensuring Conformance to ASTM A780
The specification explains how to use the various repair methods as well as the required coating thickness for the repaired area. Galv What does the cold galvanizing process consist of? Inorganic binders are particularly suitable for paints applied in touch-up applications of undamaged hot-dip galvanized areas. 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.
When it comes to repairing galvanized steel in the field, there is no limitation to the size that can be repaired. Zinc spray, or metallizing, is done a70 melting zinc powder or zinc wire in a flame or electric arc and projecting the molten zinc droplets by air or gas onto the surface to be coated.
Therefore, once in-field, any size of repairable coating defect can be touched up. Ensure a blotter test is performed prior to using a compressed air source in accordance with ASTM D Brite Zinc meets and exceeds this percent. Hand tool cleaning with a stiff-bristle or nylon brush does not meet specification.
Topics will include proper equipment and materials to use while performing the process, explanation of the specifications to follow, and examples of best zstm during aztm of the repair materials.
Galv Touch Up Methods Dr. For less critical field exposure conditions, blast clean the surface to near-white metal, in accordance with SSPC-SP10 1 to 2 mil 25 to 50 m anchor patternas a minimum.
In order to ensure strict adherence to the specification ASTM A when performing repairs at the galvanizing plant, the galvanizer should be well versed in the equipment, materials and surface preparation standards required of each repair method. Do not immediately apply repair materials over a freshly cleaned surface. Call for more s780. The six-part video series will provide highly beneficial visual aids to those needing assistance with meeting the requirements of ASTM A At the galvanizing facility, the maximum allowable repair size for iron and steel products per ASTM A is no more than 1 inch [2.
ASTM AZinc Dust in Paint | American Galvanizer’s Association
Authored by Alana Hochstein. The area being repaired needs to be preheated to approximately F C.
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. Referenced Documents purchase separately The documents listed below are ast, within the subject standard but are not provided as part of the standard. ASTM A contains three acceptable methods of touch-up and repair of hot-dip galvanized steel: Although some of the requirements within ASTM A are relatively straightforward, other requirements related to surface preparation often astj clarification.
If replica tape is utilized, two readings are to be taken z780 each location and averaged to get one “measurement” of the profile of the surface. This abstract is a brief summary of the referenced standard. Where circumstances do not allow blast cleaning, it a80 permissible to power disk sand areas to be repaired to bright metal. Galv Touch-Up and Repair Dr. 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 areas remaining after initial hot-dip galvanizing.
Brite Zinc is an organic zinc compound.