The apparatus includes a pair of cooled, rotating casting rolls forming a nip between them. Molten metal is delivered into the nip between the casting rolls to form a casting pool of molten metal supported on the rolls. The cast strip produced is delivered downwardly from the nip and guided through a transit path which takes it away from the nip. An enclosure confirms the strip throughout the transit path and includes an enclosure wall including a movable section disposed beneath the casting rolls and formed to serve as a movable receptacle for scrap produced at any stage of the casting process, which enclosure is sealed to control ingress of oxygen containing atmosphere during operation of the apparatus, thereby controlling the formation of scale on the strip during operation of the apparatus.