I'm just about finished building my darkroom sink. I'm basing my design on one I found in an old darkroom book. Basically, it is made of plywood then, waterproofed with epoxy paint. I've got the sink built, and am ready to caulk the seams again just to be safe, before applying the epoxy paint. Has anyone built a similar sink and have any tips or suggestions? The joints already have caulk in them, and the instructions call for more caulk to be applied prior to the painting. You paint it, then apply caulk again just in case. Sounds pretty straightforward, and so far everything has gone pretty well.