A device is provided for applying and/or finishing viscous materials along at least one adjoining surface or a bead along a corner, while simultaneously effecting all of the surfaces substantially free of any excess of the viscous material. The device includes a reinforcing portion (24), at least one operative extension (34R), (34L) with a working edge (56R), (56L) that protrudes beyond the termination (out of view) of the reinforcing portion, and a forward working edge (36), (38). The viscous material is formed with the forward edge. The angle of the operative extension edge to the forward edge is variable and resilient, which conforms to irregularities of the corner and variations in the position of the reinforcing portion and the forward working edge in relation to the adjoining surface, while sidewardly force is maintained against the adjoining surface. A seal is produced and maintained between the extension edge and the adjoining surface. The seal continuously prevents the viscous material from oozing between the extension edge and the adjoining surface, whereby a uniform clearly defined junction of the smooth applied surface and the clean unscathed adjoining surface is easily and efficiently produced.