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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This practice can also be used to repair hot-dip galvanized coatings damaged by excessively rough handling during shipping astm a780 erection.
When ready to perform mechanical cleaning, check the surface preparation standard for clarity on the allowable tooling a708. Effective May 1st 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. Inspector Listing – Non-U.
At the galvanizing facility, the maximum allowable repair size astm a780 iron and steel products per ASTM A is astm a780 more aetm 1 inch [2.
Most organic zinc-rich paints are not critical of climatic or atmospheric conditions for curing. Experience shows that in general organic zinc-rich systems are more tolerant of surface preparation. A listing of various manufacturers and products for the maintenance and repair of hot-dip galvanized structures is available for download.
Zinc spray, or metallizing, is astm a780 by melting zinc powder or zinc wire in astm a780 flame astm a780 electric arc and projecting the molten zinc droplets by air or gas onto the surface to be coated. The damage may be the result of welding or cutting flamein which case the coating will be damaged predominantly by burning.
ASTM AZinc Dust in Paint | American Galvanizer’s Association
In order to ensure strict adherence to the specification ASTM A when performing repairs at the galvanizing a7780, the galvanizer should be well versed in the equipment, materials and surface preparation standards required of each repair method.
It is the responsibility astm a780 the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Although some of the requirements within ASTM A are relatively straightforward, other requirements related to surface preparation often require clarification. Astm a780 not average the readings, as this requirement was removed from the specifications in Soldering is done with zinc-based alloys in either a stick or powder form.
Although the hot-dip x780 coating is very resistant to damage, small voids or defects in the coating can astm a780 during the galvanizing process or due to improper handling of the steel after galvanizing.
Link to Active This link will always route to the current Active version of the astm a780. Galv Touch Up Methods Dr.
Hand tool cleaning with a asttm or nylon brush does not astm a780 specification. Inspection of Cleaned Surfaces After surface preparation, the standards refer to points of inspection necessary to ensure proper adhesion of the repair material.
Call for more information. 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. Zinc Spray Metallizing Zinc spray, or metallizing, is done by melting astm a780 powder or zinc wire in a flame or astm a780 arc and projecting the molten zinc droplets by air or gas onto the surface to be coated.
The practice is the same, but there are more restrictions to the allowable repairs on astm a780 new product than one that has been in service.
Inch-pound units and SI units are not necessarily exact equivalents. Each system shall be used independently of the other without combining values in any way. Touch-up materials are required to meet a coating thickness of at least 2. Any dust or loose residue astm a780 cleaning must be brushed away using a stiff-bristle brush or blown off astm a780 clean, dry air.
ASTM A780-Zinc Dust in Paint
The practice for repairing the galvanized a708 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. Ensure a blotter test is performed prior to astm a780 a compressed air source in accordance with ASTM D Similarly, contracting parties shall agree to the repair method to be used.
Within the astm a780 of this specification and where appropriate, SI units are shown in brackets. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. Authored by Alana Hochstein.
Repairing HDG Steel
The main restriction in astm a780 specification for repairing newly galvanized material is the size of the area which is outlined in the product galvanizing specifications:. Historical Version s – view previous versions of standard.
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.
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. Astm a780 power tool cleaned surfaces, a surface profile depth micrometer is the appropriate method for confirming profile, unless otherwise agreed. Brite Zinc meets and exceeds this percent. This is especially applicable for abrasive blast cleaned astm a780, where astm a780 appropriately sized blasting unit and hose should be astm a780.