and disappear without any apparent reason as well. The
appearance of these flaws is chaotic and probabilistic. How-
ever, as information continued to accumulate, a relationship
between the seasonal fluctuations in the hardness of the wa-
ter used in the process and the amount of flaws was estab-
lished. Next a relationship between the amount of salts in the
water, the rheological properties of the enamel coating, and
the properties of the melt was established , and this knowl-
edge made it possible to adopt certain measures to prevent
the appearance of the defects.