Excess Aluminum in Galvanizing Bath
Another type of surface defect, shown in the image to the left, is caused by an excess amount of aluminum in the galvanizing bath. This creates bare spots, seen as black marks, on the surface of the steel. The part may be repaired only if small areas of bare spots are evident. If this condition occurs over the entire part, the part must be rejected, stripped, and regalvanized.
© 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.