In 1970, a patent was awarded to NASA for a zinc silicate primer coating called K-Zinc 531, the name owing to the ratio of silicon/potassium to water being 5:3:1.
A patent was awarded to NASA for a zinc silicate primer coating. This was in 1970. This zinc silicate primer coating was called K-Zinc 531/potassium to water. This zinc silicate primer coating was being 5:3:1. Zinc 531 was the name. This name was owing to the ratio of silicon.