An adjustable sander comprising: a body; a flexible base having a first end and a second end spaced apart from one another, and wherein the first end and second end is each pivotally attached to the body, and wherein the flexible base is configured to move between a concave configuration, a neutral configuration, and a convex configuration relative to the body; a removable sanding surface affixed to a surface of the flexible base that is distal from the body; a locking mechanism configured to selectively hold the flexible base in a desired concave, neutral or convex configuration; and characterized in that the locking mechanism comprises: an axial including a head and a shaft, and wherein the shaft includes a series of shaft notches; a sleeve configured to be positioned around the shaft; a selector having an operator surface and a holder coupled to the selector, wherein the operator surface is accessible from outside the body and the holder includes an engagement surface having at least one holder notch configured to selectively engage at least one of the shaft notches, and wherein said selector is selectively movable between an engaged position wherein the at least one holder notch is engaged to one of the shaft notches, and a disengaged position, wherein the at least one holder notch is disengaged from the shaft notches. a body; a flexible base having a first end and a second end spaced apart from one another, and wherein the first end and second end is each pivotally attached to the body, and wherein the flexible base is configured to move between a concave configuration, a neutral configuration, and a convex configuration relative to the body; a removable sanding surface affixed to a surface of the flexible base that is distal from the body; a locking mechanism configured to selectively hold the flexible base in a desired concave, neutral or convex configuration; and characterized in that the locking mechanism comprises: an axial including a head and a shaft, and wherein the shaft includes a series of shaft notches; a sleeve configured to be positioned around the shaft; a selector having an operator surface and a holder coupled to the selector, wherein the operator surface is accessible from outside the body and the holder includes an engagement surface having at least one holder notch configured to selectively engage at least one of the shaft notches, and wherein said selector is selectively movable between an engaged position wherein the at least one holder notch is engaged to one of the shaft notches, and a disengaged position, wherein the at least one holder notch is disengaged from the shaft notches. an axial including a head and a shaft, and wherein the shaft includes a series of shaft notches; a sleeve configured to be positioned around the shaft; a selector having an operator surface and a holder coupled to the selector, wherein the operator surface is accessible from outside the body and the holder includes an engagement surface having at least one holder notch configured to selectively engage at least one of the shaft notches, and wherein said selector is selectively movable between an engaged position wherein the at least one holder notch is engaged to one of the shaft notches, and a disengaged position, wherein the at least one holder notch is disengaged from the shaft notches.