Gashi mai ɗumi-ruwa wani nau'i ne na galvanization. Tsarin ƙarfe ne da baƙin ƙarfe tare da zinc, wanda keɓaɓɓen ƙarfe tare da farfajiyar ƙarfe na ƙarfe yayin nutsar da ƙarfe a cikin wanka na zinc mai ƙyalli a zazzabi kusan 840 ° F (449 ° C). Lokacin da aka fallasa ga yanayi, zinc (Zn) mai tsabta ta amsa tare da oxygen (O2) don samar da zinc oxide (ZnO), wanda ke sake haɗuwa da carbon dioxide (CO2) don samar da zinc carbonate (ZnCO3), yawanci mara nauyi ne, mai ƙarfin gaske. abu wanda ke kare baƙin ƙarfe a ƙarƙashin daga lalata a cikin yanayi da yawa. Galvanized steel ana amfani dashi sosai a cikin aikace-aikace inda ake buƙatar jure ƙarfin lalata ba tare da farashin ƙarfe na bakin karfe ba, kuma ana ɗauka mafi girma dangane da farashi da tsarin rayuwa.