If you can get your hand on a bundle of plaster lathe you can nail them to a 2 x 2 at both the top and bottom. Use small galvanized nails and predrill the lathe at the top and bottom to keep from splitting. Use one edge of a lathe as a spacer. Make your legnth and your width to suit your need. Use to make mine 4'x8' but 3'x5' will work fine. Once you have all four sides made and fastened together by nailing the 2x2s then nail 1x6s across the top to form the bottom using a lathe again as a spacer. Flip it over. About 1/3 of the way down from the top, nail a 1x4 around the outside perimeter making sure the ends overlap each other. This forms a ledge that you can attach some floats to keep it floating. You now have a live box. You can even make a divider to slide in to keep your peelers seperated.