“Measurement of Dry Coating Thickness with magnetic Gages” HOW MUCH IS ENOUGH? Statistical method to determine the minimum number of readings required. SSPC-PA 2 – Measurement of Dry Paint Thickness with Magnetic Gauges Procedures to Measure Dry Film Thickness of Nonmagnetic Coatings over Magnetic Substrates…
Category: GALVANIZING
ADDITIONAL TEST IN GALVANIZED STEEL
Every hot-dip galvanized steel part is inspected for coating thickness and visually for appearance and finish. However, there are a few additional tests that may be conducted on certain types of parts or when there is a question or concern about a specific item. Adherence…
GALVANIZED COATING THICKNESS REQUIREMENT ASTM A123
ASTM A123/A123M covers individual steel pieces as well as assemblies of various classes of material. The six material categories covered in ASTM A123/A123M include structural shapes, plate, strip and bar, pipe and tubing, wire, and reinforcing bar. A fabrication can have more than one material category such as a frame assembly.…
Inspection of HDG
Similar to any manufacturing process, hot-dip galvanized steel requires an inspection of the finished product to ensure compliance with applicable specifications. The inspection process requires a clear understanding of galvanizing specification requirements and measurement techniques to make an accurate assessment. A key feature of hot-dip…
Steel + Zinc = Hot-Dip Galvanizing
Hot-dip galvanizing (HDG) is the process of coating fabricated steel by immersing it in a bath of molten zinc. There are three fundamental steps in the hot-dip galvanizing process; surface preparation, galvanizing, and inspection. Surface Preparation When the fabricated steel arrives at the galvanizing facility,…
HOT DIP GALVANIZING
Hot-dip galvanizing is the process of immersing iron or steel in a bath of molten zinc to produce a corrosion resistant, multi-layered coating of zinc-iron alloy and zinc metal. While the steel is immersed in the zinc, a metallurgical reaction occurs between the iron in…
Venting & Drainage in HDG
Box Sections The figure (right) shows the location of holes and clipped corners, which must be flush. Using the following formulas, the table below shows typical sizes of holes for square box sections only. For rectangular section, calculate the required area and check with your…
Venting & Drainage in HDG
In the hot-dip galvanizing process, steel is completely coated with corrosion-inhibiting zinc, which forms a highly abrasion-resistant metallurgical bond with the base steel. In order to ensure that all interior and exterior surfaces are protected from corrosion, entire steel fabrications are lowered into and raised…
Reasons for Duplex Coating
There are seven good reasons to paint or powder coat hot-dip galvanized steel: Extended Durability – in what is called the synergistic effect between galvanized steel and paint, the zinc of the galvanized coating is a barrier protection to the substrate steel, cathodically protects it,…
Weld Slag Clean Up Requirements for Galvanizing
When welded structures are hot-dip galvanized, the weld area cleanliness significantly affects the quality and appearance of the galvanized coating around the weld. If a coated electrode (i.e. a flux-coated welding wire/rod/stick) is used during welding, all welding flux and slag must be cleaned prior…