a semi - cylindrical low - profile cantilevered paddle of refractory material is separably clamped to a cantilevered arm fastened to a movable boat - loader . a clamping mechanism is disclosed that preferably includes spaced brackets fastened to the arm defining retaining loops for slidably receiving the paddle . a flexible , stress - relief saddle portion is provided on one of the brackets . the rugged and breakage - resistant semi - cylindrical paddle is inexpensive to procure and replace , and its low profile makes it possible to adapt existing cvd furnaces for operation with larger semiconductor wafers .