Inside a Sealed Container A piece of steel wool (very thin steel fibers, made mostly of iron) is placed on a scale. Electric current is passed through the steel wool. the steel wool is in a container with a metal bottom and plastic sides. The container is placed on a small scale, which has been zeroed so it shows just the mass of the steel wool. Then, the small scale is placed on a large scale which shows the mass of the steel wool, the container, and the small scale. Describe what happened to the scale readings