Alumacraft the alumacraft 12′ flat-bottom jon boat features 4 extruded aluminum ribs and pressed-in chines for strength and great tracking. alumacraft 12′ flat-bottom. Atkin & co boat plans, boat designs, boat building, william atkin, john atkin, billy atkin, small boats, good boats. Stephen pollard aluminum designs. glen-l is proud to offer designs by stephen pollard for welded aluminum construction complete with cad files. stephen pollard is the.