Code: HOT DIP GAVALNIZED REPAIR PROCEDURE DIM-22117 Rev: 00 Issued Date: 30/08/2023 TABLE OF CONTENTS 1. PURPOSE .........................................................................................................................................................2 2. SCOPE OF APPLICATION ..............................................................................................................................2 3. REFERENCE CODE & STANDARD................................................................................................................2 4. APPLICATION PRODUCT ...............................................................................................................................2 5. RESPONSIBILITIES .........................................................................................................................................2 6. REPAIR PROCEDURE .....................................................................................................................................2 7. INSPECTION.....................................................................................................................................................3 Code: HOT DIP GAVALNIZED REPAIR PROCEDURE DIM-22117 Rev: 00 Issued Date: 30/08/2023 1. PURPOSE - This procedure establishes various requirements and a method for the repair of damaged Zinc Coating of all hot dip galvanized structural steel shapes and other fabricated products to have a good protective system 2. SCOPE OF APPLICATION - This Procedure details the method for repair of damaged zinc coatings which can be used for hot dip galvanized structural steel shapes and other fabricated products on damaged areas caused by welding, cutting, drilling rough handling during shipping / erection at site 3. REFERENCE CODE & STANDARD 4. - EN ISO 1461: 2009 Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products - ASTM A780 Repair of Damaged and Uncoated Areas of Hot-Dip Galvanized Coatings APPLICATION PRODUCT - Applies to all general steel such as iron and steel tubes, steel, steel plates, scaffolding, beams, columns and assembling manufactured steel, reinforced, steel structure, ... and other steel components 5. RESPONSIBILITIES - Factory Manager: Overall in charge of the implementation of this procedure. Directs to relevant team for the proper actions required in terms of performance quality and safety. - Production Manager: ln charge for the supervisor of the entire process handling. - Quality Manager: Oversees the repair process and make sure that the standards of this procedure is being followed and implemented. Likewise, the acceptance tolerance and proper practice 6. REPAIR PROCEDURE - Damaged surfaces to be repaired shall be clean, dry, free of oil, grease, corrosion products. - If the damaged areas are greater than 2% of a member area they shall be blasted to Sa2 (SP6) and repaired by re-dipping the member in hot Zinc bath. - If the damaged areas are less than (or) equal to 2% of the total coated area of the member shall be Code: HOT DIP GAVALNIZED REPAIR PROCEDURE DIM-22117 Rev: 00 Issued Date: 30/08/2023 power tool cleaned to ST3 (SP3) or hand tool cleaning to SP2. Grinding cleaned surface should have an anchor profile minimum 25 microns. - To ensure a smooth re-conditioned coating that can be effected, surface preparation shall extend into the undamaged galvanized coating. - If the area to be reconditioned includes welds, first remove all flux residue and weld spatter of a size (or) type that can’t be cleaned by blasting.these shall be cleaned by mechanical means by chipping, etc. - Spray cold galvanized (or) Brush paints containing Zinc dust (minimum of 94% Zinc dust by weight) to the prepared area. Apply in single application employing multiple spray passes to achieve a dry film thickness of minimum 75 microns to maximum 125 microns according to ASTM A780. Then application for topcoat by Cold Galvanizing to achieve a dry film thickness of minimum 85 microns. 7. INSPECTION - Check that surface preparation is as specified. - Check the coating thickness with either magnetic (or) electromagnetic gauge to ensure that coating is as specified - Ensure this procedure is follow properly
