7 Jun ASTM A states zinc-rich paint with zinc dust in the ranges of % or above 92% in the dried film are equally effective. Why is there a gap. 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 . 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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Color red A7880 10 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.
Home Tags Login Register Search. To ensure that a smooth reconditioned coating can be effected.
Ensuring Conformance to ASTM A780
Do not immediately apply repair materials over a freshly cleaned surface. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phone. Soldering is done with zinc-based alloys in either a stick or powder form. The area being repaired w780 to be preheated to approximately F C. Inspection of Cleaned Surfaces After surface preparation, the standards refer to points of inspection necessary to ensure proper adhesion of the repair material.
Finally, a visual inspection to confirm the level of cleanliness must be carried out to ensure the standard is met. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Each system shall be used independently of the other without combining values in any way. Inch-pound units and SI units are not necessarily exact equivalents.
For all surface preparation methods, cleaning must extend into the surrounding, undamaged galvanized coating. Inspector Listing – Non-U.
ASTM A – Free Download PDF Ebook
The zinc coating is difficult to damage, and field fabrication that requires removal of the coating should be minimized as much as possible. ASTM A contains three acceptable methods of touch-up and repair of hot-dip galvanized steel: The practice is the same, but there are more restrictions to the allowable repairs on a new product than one that has been in service. Authored by Alana Hochstein.
The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. Users of this standard are expressly advised that determination of the validity of any such patent rights.
Repairing HDG Steel
Although some of the requirements within ASTM A are relatively straightforward, other requirements related to surface preparation aa780 require clarification. Experience shows that in general organic zinc-rich systems are more tolerant of surface preparation.
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. Paints containing zinc dust are classified ast, organic or inorganic, depending on the binder they contain. The six-part video series will provide highly beneficial visual aids to those needing assistance with meeting the requirements of ASTM A Always check for visible contaminants on the surface of the repair area just prior to mechanical cleaning.
ASTM AZinc Dust in Paint | American Galvanizer’s Association
The main restriction in the specification for repairing newly galvanized material is the size of the area which is outlined in the product galvanizing specifications:. Mon Jun 3 Corrosion resistance and service performance are very dependent on the properties of the paint system.
Brite Zinc meets and exceeds this percent. For best results, thickness measurements for the metallized coating should be taken with either a magnetic or an electromagnetic gauge.
Similarly, contracting parties shall agree to the repair method to be used. No further reproductions authorized. Annex A2 describes the use of paints containing zinc dust. High Zinc Dust Content. If replica tape is utilized, two readings are to be taken over each location and averaged to get one “measurement” of the profile of the surface. The most common types of solders are zinccadmium, zinc-tin-lead, and zinc-tin-copper alloys.