A system of wax tubes (sprues) is then attached to the wax pattern to create channels through which the bronze will eventually flow.

 

Sprues are attached by heating the ends with a hot tool and affixing to the wax pattern at regular intervals.

 

The sprues rise up to a single point above the wax pattern, to which a funnel shaped wax cup is attached.

 

It is through this point that the bronze will be poured.