Andy Florin, age 15, of Austin, Texas, for his question:

WHAT IS GALVANIZED IRON?

To prevent iron and steel from rusting, sometimes they are coated with zinc. Back in the 1800s, wrought iron coated with zinc became known as galvanized iron. Then later when steel items were also coated with zinc, the name "galvanized iron" was still used to describe them.

At the present time, a great deal more steel than iron is coated with zinc.

Before dipping the items into a bath of melted zinc, they must be thoroughly cleaned in an acid bath. This procedure is called hot dip galvanizing.

This process is used to galvanize steel sheets, pails, pipes, nails and wire.

A galvanized item has a mottled appearance because when the zinc cools, it leaves tiny drops of zinc on the surface of the iron or steel.

Sometimes iron or steel items are galvanized by putting them into a solution in which zinc or zinc salts are dissolved. Then electricity is used to transfer or plate the articles.

The first patent for galvanizing iron was issued in 1837 to an Englishman named H.W. Craufurd.