That's actually not a bad idea. Build it sans feet, then glue it into a standard hex base, or another one with a recessed top. Fill it partially with some kind of liquid filler(I'd go for elmer's glue for cheapness), and let it dry completely while sitting at an angle. When that's done, add some more glue, put it back at an angle, and let it dry again. Lather, rinse, repeat, until the base is full. You'll end up with a smooth surface that has fluidlike ripples on it. O0