An adhesive melter includes a melter tank with an interior communicating with a top opening, a sealing flange surrounding the top opening, and a lid assembly. The lid assembly includes guide rails and a lid for sliding on the guide rails between an open position exposing the top opening a closed position over the top opening. The lid includes a closure surface that slides generally along a plane of the sealing flange when the lid slides on the guide rails, and the closure surface also moves in a direction transverse to the plane defined by the sealing flange simultaneous to this sliding movement. The sliding movement of the lid enables an operator to grasp the handle and control the lid movement over the full range of lid movement, while the transverse movement of the closure surface avoids stiction forces from preventing sliding movement.