Careful planning must be a part of a successful end product. The biggest problem with casting resin is the heat build up. I constructed a mold for a 3" thick top by building a flowing water bath around it. This will help me cool it down and control the heat which can cause cracking and warping. I also am adding an extruded panel of polycarbonite to gain stability. Same with the pour for the legs that will support the top.