Abstract: Gunning apparatus adapted to be carried by a mobile device such as a fork lift truck and inserted in a side door of a furnace such as an electric furnace and used to gun refractory material onto the inside surface of the furnace lining comprises a boom with one end adapted to be attached to the mobile device and the other end carrying a spray nozzle which can be rotated about a vertical axis, the boom also carrying channels to convey, separately, refractory and water to a mixer where the refractory and water are admixed, a channel to carry the admixture to the spray nozzle, and a motor to rotate the spray nozzle.