Bare spots, uncoated areas on the steel surface, can occur because of inadequate surface preparation. Bare spots may be caused by welding slag, sand embedded in castings, excess aluminum in the galvanizing kettle, or lifting devices that prevent coating formation in a small area. To avoid bare spots, (left) the galvanizer must ensure surfaces are clean and rust-free after pretreatment. Small bare spots can be repaired, but if the size of the bare spot or total number of spots causes rejection, the parts may be stripped, regalvanized, and then re-inspected for compliance to the specifications.
© 2019 American Galvanizers Association. The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. 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 the AGA. Anyone making use of this information assumes all liability arising from such use.