Abstract: A sander for smoothing curvilinear surfaces includes a horizontal support surface having top and bottom sides. The support surface has two sets of inner and outer arcuate slots thereon. The inner arcuate slots each have idler rollers thereabove secured to a pivoting, spring biased circular plate therebelow. A continuous sanding belt encompasses the idler rollers and a drive roller and is moved along a substantially triangular path with a motor means. A section of the path defines a sanding portion immediately adjacent to which is a flexible plate. An adjustment mechanism is provided to bend the plate to a desired configuration to form a curved sanding portion. The plate has an anchoring post on each side that is received within an outer arcuate slot and is secured to the circular plate therebelow. The plates, idler rollers and anchoring posts maintain tension on the belt regardless of the orientation of the sanding surface.