What is it?
This defect usually appears during the pickling process. It is typically a dark red, brown, or yellow stain. It can appear in patches (photo 1), linear marks (photo 2) or a combination (photo 3). This defect is also called rust, red rust, or pickle stain. The defect is caused by worn wringer rolls, or a malfunction in the rinse sections of the pickle line. In addition, problems in the drying section of the pickle line or a line-stop can cause rinse stains.