A brush assembly using a spacer and the spacer permit multiple brushes to be combined on a driveshaft that is driven in rotation. The use of multiple brushes allows one to vary the characteristics of the brush assembly along the assembly's length. This also permits one to change fewer than all brushes when needed, thereby saving the cost of replacing an entire brush assembly's brushes when worn. The spacer is a body with a central opening that is preferably polygonal in section, opposing ends that form shoulders and a radially extending gasket located intermediate the opposing ends.