Is galvanized metal tin?
Thereof, how can you tell if metal is galvanized?
Using a magnet or gauge will only determine if there is a zinc coating on top of the steel. And as a matter of fact, the gray coating she sees may be just paint. A film of paint would have a thickness to it. The only real way to determine if the coating is hot-dip galvanized would be to run laboratory testing.
Subsequently, one may also ask, will galvanized tin rust?
Zinc can't rust (although it can corrode into a white gummy or powdery corrosion product). So, no, you can't 'rust' galvanized steel sheet metal while it still has the zinc coating on it. Again, tin can't rust; only iron and steel can rust.
Galvanization is the process of applying a protective zinc coating to steel or iron in order to prevent premature rust and corrosion. The corrosion of zinc is very slow, which gives it an extended life while it protects the base metal. Due to the alloying of the Zinc to the iron, cathodic protection occurs.