The purpose of this apparatus is to join split panels which have warped without first having to straighten the warps, even along the line of the join. The apparatus is adaptable enough to be useful for any other gluing operations. It consists of a trestle table to which the two parts of the panel are clamped so as to lie horizontally; and a separate vertical frame with beams above and below the table, onto which adjustable clamps can be made to bear.