Bronze Casting - Setting Up the Shells

At this point we're stepping back before the crucible is lifted from the furnace. Before that step occurs you have to set up the molds - or "shells" - so they can receive the molten bronze.

This is a rather frenzied activity since 1) the shells are preheated to 1600 degress F so the bronze won't freeze before it fills the molds, and 2) the shells must be covered in sand so they will not cool significantly (which will also cause the bronze to freeze prematurely). As you may guess, setting up the shells in the supporting sand beds must be done quickly and with proper technique.

The oven for heating the shells is seen, partially opened, in the background. The workers wears protective leather gloves as always, but because the shells are so hot the gloves alone won't protect the hands from the heat. So you use another pair of water soaked (and old) leather gloves as padding between your gloves and the shell. The water evaporates and has a cooling effect. So if done quickly and properly the temperature at the surface of your gloves does not go beyond 212 degrees F. The water soaked pair of gloves are then thrown down and another fresh pair picked up. The technique, it must be emphasized, is to move quickly but orderly.

As one person holds the shell in place - with the opening covered with foil to keep out the dust - sand is poured around the mold to give additional support. The next picture shows that step more clearly.