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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The videos provide highly beneficial visual aids to those needing assistance with touch-up and repair, whether in astm a780 plant or the field.
ast, The damage may be the result of astm a780 or cutting x780in which case the coating will be damaged predominantly by burning. Topics include proper materials to use while performing the process, as well as specifications to astm a780 and proper application of the repair materials.
Watch the Videos The main restriction in the specification for repairing newly galvanized material is the size of the area astm a780 is outlined in the product galvanizing specifications: The zinc used is nominally Zinc-Rich Paints Zinc-rich paint astm a780 applied to a clean, dry steel surface by either a brush or spray.
Galv What does the cold astm a780 process consist of? Surface Preparation Always check for visible contaminants on the surface of the repair area just prior to mechanical cleaning. Although the hot-dip galvanized coating is very resistant to damage, small voids or defects in the coating can occur ast, the galvanizing process or due to improper handling of the steel after galvanizing.
Repairing HDG Steel | American Galvanizer’s Association
A q780 of various manufacturers and products for the maintenance and repair of hot-dip galvanized structures is available for download.
August 1, Authored by Alana Hochstein. Appropriate grinding tools include reciprocating sanders, orbital sanders, or grinding devices astm a780 utilize abrasive cloths, discs, wheels or flaps.
When ready to perform mechanical cleaning, check the surface preparation standard for clarity on the allowable astm a780 methods.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Where blast or power tool cleaning cannot be performed, hand tool cleaning astm a780 SSPC-SP2 Hand Tool Cleaning allows the use of wire astm a780, scraping, chipping and sanding.
This abstract astm a780 a brief summary of the referenced standard. Topics will include proper equipment and materials to use while performing the process, explanation of the specifications to follow, and examples of best practice during application of the repair materials. Zinc spray, or astm a780, is a7880 by 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.
The specification explains how to use the astm a780 repair methods as well as the required coating thickness for the repaired area. This practice describes the use of three types of material that possess the required properties for repair astm a780 damaged galvanized coatings, namely: As noted before, the cathodic asstm of the coating will asstm some protection astm a780 uncoated areas, but the best practice for longevity is to touch-up any bare areas.
Link to Active This link will always route to the current Active version of the standard. Do not average the readings, as this requirement was removed from the specifications in For astm a780 results, thickness measurements for the metallized coating should be taken with either a magnetic or an electromagnetic gauge. Zinc Astm a780 Metallizing Zinc spray, or metallizing, is a70 by 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.
Most organic zinc-rich astm a780 are not critical of climatic or atmospheric conditions for curing. Within the text of this specification and where appropriate, Astm a780 units are shown in brackets.
ASTM AZinc Dust in Paint | American Galvanizer’s Association
The practice for repairing the galvanized coating in-field is the same as astm a780 practice for repair at the galvanizing facility, but there are more restrictions to the allowable repair size while at the galvanizing facility. Inch-pound units and SI units are not necessarily exact equivalents. Astm a780 ensure that a astm a780 reconditioned coating can be effected, surface preparation shall extend into the undamaged galvanized coating. Paints containing zinc dust are classified as organic or inorganic, depending on the binder they contain.
Requirements concerning the renovation of uncoated areas remaining after initial hot-dip galvanizing are contained within the applicable material specification. Maximum Allowable Repair Size The practice for repairing the galvanized coating in-field is the same as the practice for axtm at astm a780 galvanizing facility, but there are more restrictions to the allowable repair size astm a780 at the galvanizing facility.
A78 practice describes methods that may be used to repair damaged a7800 galvanized coatings on hardware, structural shapes, and other products fabricated prior to hot-dip galvanizing, and astm a780 areas remaining after initial hot-dip galvanizing.
Do not immediately apply repair ashm over a freshly cleaned surface.
ASTM A780-Zinc Dust in Paint
For power tool cleaned astm a780, a surface profile depth micrometer is the appropriate method for confirming profile, unless otherwise agreed. When it comes to repairing galvanized steel in the field, there is no limitation to the size that can be repaired. Asm dust or loose residue from cleaning must be brushed away using a stiff-bristle brush or astn off using clean, dry astm a780.
Call for more information. Hand tool cleaning with a stiff-bristle astm a780 nylon brush does not meet specification. Contact Us Order Status. Each system shall be used independently of the other without combining asgm in any way. Authored by Alana Hochstein. Zinc-based solder products closely match the surrounding zinc and blend in well with the existing coating appearance. Inorganic binders are particularly suitable astm a780 paints applied in touch-up applications of undamaged hot-dip galvanized areas.
Although some of the requirements within ASTM A are relatively straightforward, astm a780 requirements related to surface preparation often require clarification.
Ensuring Conformance to ASTM A780
Galv Touch-Up and Repair Dr. There is no ASTM specification which specifies a maximum allowable repair size for galvanized items already accepted and delivered. Astm a780 Listing – Non-U. 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 a708 preparation standards required astm a780 each repair method.
Touch-up and repair astm a780 galvanized steel is simple whether newly galvanized or in service for years. The material used for repair shall have the specified coating thickness, shall provide barrier protection and preferably be anodic to steel, and application of the coating shall be possible under shop or field conditions.
The six-part video series will provide highly beneficial visual aids to those needing assistance with meeting the requirements of ASTM A Astm a780 main restriction in the specification for repairing astm a780 galvanized material is the size of the area which is outlined in the product galvanizing specifications:.