The bottom part of the forge, where the fire pan will be mounted on top of. This chamber allows the air to expand and distribute evenly, ensuring a uniform air flow. The hole for the air tube was not so much drilled as simply cut out.

A word of warning here; do NOT use galvanised steel in any part of this construction, as it can give off toxic fumes when exposed to extreme heat.. The pipe here is painted, not galvanised.