– Make one type of frame for everything.
– Different types of surfaces can be placed on standard frames.
– In order to stack frames, there can be no overhang on the benchtop surface.
– Use 40x40x2.5
– Aim for a work surface height of about 780
– Frame outer dimensions 1800 x 1200
– Start with horizontal top frame using mitred corners
– Support strip in center to prevent Formply sagging
– This fits a FormPly sheet of 1800 x 1200 x 17
– Weld angle iron strips on corners for vertical stacking (close to flush with 17mm FormPly at 15mm)
– For welding table surface, make a press fit removable frame-inside-the-frame and weld on slats.
– Halfway down the frame you can weld a H brace to hold a shelf with 40×40 corner cutouts and enough leg room.