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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Do not average the readings, as this requirement was removed from the specifications in 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. The videos provide highly beneficial visual aids to those needing assistance with touch-up and repair, whether in the plant or the field.
For all surface preparation methods, cleaning must extend into the surrounding, undamaged galvanized coating. 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.
Galv Touch Up Methods Dr. The method and extent of surface preparation shall be mutually agreeable to the contracting parties. The specification wstm how to use the various repair methods as well as the required coating thickness for the repaired area. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. Requirements concerning the renovation of uncoated areas atm after initial hot-dip galvanizing are contained within the applicable material specification.
Finally, a visual inspection to confirm the level of cleanliness must be carried out to ensure the standard is met. Appropriate grinding tools include reciprocating sanders, orbital sanders, or grinding devices that utilize abrasive cloths, discs, asfm or flaps. 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.
Asfm Preparation Always check for visible contaminants on the surface of the repair area just prior to mechanical cleaning. Authored by Alana Hochstein.
Ensuring Conformance to ASTM A | American Galvanizer’s Association
Most organic zinc-rich paints are not critical of climatic or atmospheric conditions for curing. ASTM does not give any asym express or implied or make any representation that the contents of this abstract are accurate, complete or up to date. Link to A870 This link will always route to the current Active version of the standard.
The touch-up and repair of hot-dip galvanized steel coatings is important to maintain uniform barrier and cathodic protection as well as ensure longevity. However, do not clean excessively beyond the area of repair.
Repairing HDG Steel
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. The damage may be the result of welding or cutting flamein which case the coating will be damaged predominantly by burning.
Within the text of this specification and where appropriate, SI units are shown in brackets. Always check for visible contaminants on the surface of the repair area just prior to mechanical cleaning.
Do not immediately apply repair materials over a freshly cleaned surface. Brite Zinc meets and exceeds this percent. Effective May 1st Contact Us A80 Status. Although some of the requirements within ASTM A are relatively straightforward, other requirements related to surface preparation often require clarification.
The six-part video series will provide highly beneficial visual aids to those needing assistance with meeting the requirements of ASTM A Zinc-rich paint is applied to a clean, dry steel s780 by either a brush or spray.
Galv Touch-Up and Repair Dr. Correct for the additional tape thickness i. Inspector Listing – Non-U. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. The information provided herein is not intended as a representation or warranty on the part of asstm AGA.
Similarly, contracting parties shall agree to the repair method to be used. 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.
ASTM AZinc Dust in Paint | American Galvanizer’s Association
For power tool cleaned surfaces, a surface profile depth micrometer is the appropriate method for confirming profile, unless otherwise agreed. Paints containing zinc dust are classified as organic or inorganic, depending on the binder they contain. It is important to note that the size restrictions apply to the area s to be repaired prior to surface preparation. The practice sstm 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.
Therefore, once in-field, any size of repairable coating defect can be touched up. This practice can also be used to repair hot-dip galvanized coatings damaged by excessively rough handling during shipping or erection.
Apply the paint as recommended by the paint asmt in a single application employing multiple a7800 passes to achieve a dry film thickness to be agreed upon between the contracting parties. 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.
Watch the Videos 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: Zinc spray, or metallizing, is done by melting zinc powder or zinc wire in a flame or electric arc ashm projecting astmm molten zinc droplets by air or gas onto the surface to be coated.
Galv What does the cold galvanizing process consist of? Touch-up and repair of galvanized steel is simple whether newly galvanized or in service for years.