Answer:

When melting with the foot of bath the most frequent wear takes place in the bottom part of the furnace. This type of wear it is known as elephant leg. By adding a new load for melting and putting power, a part of this one warms the metal of the bottom doing that this raises its temperature favouring the natural chemical wear of the silicon lining.

What can happen?

Refractory wall gets lost and it must be controlled with regular inspections.

What to do?

If it is possible, avoid working with foot of bath.