SOME SHEET-IRON ENAMEL DEFECTS TRACEABLE TO THE BASE METAL OR METAL FORMING OPERATION*

Cross sections through defects that were encountered in different plants were studied for the possible causes of the trouble. The defects that were traceable to some faulty condition in the iron are reported. It was found that hairlines, depressed lines, and blisters in the enamel may originate from some unusual condition in the metal before enameling.