A method of controlling the formation of crocodile skin surface roughness on thin cast strip of plain carbon steel forming a casting pool of molten metal of plain carbon steel of less than 0.065% carbon supported on a casting surfaces above a nip, assembling a rotating brush to contact the casting surfaces in advance of contact with the molten metal, and controlling the energy exerted by rotating brushes against the casting surfaces of the casting rolls to clean and expose a majority of the projections of the casting surfaces of the casting rolls by provide wetting contact with the molten metal of the casting pool. The cleaning step may be done by controlling the energy of the rotating brush against the casting rolls based on the difference between the measured heat flux and the initially measured heat flux when the casting surfaces are clean, and automating the method.