If the reason you are trying to build a sink is to help washing prints, I would like to suggest finding a used print washer. I am also in the situation where I can't have a proper sink, but that has not been an issue for me. In my case, I built a nice print washer, because a shop I used to work for gave me a bunch of Lexan sheets they were throwing away. From what I've seen, a used print washer is usually very close in price to the cost of new materials. My washer handles 11x14 and 8x10. On the grand occasion when I print 16x20 or 20x24, I use a tray with an old Kodak siphon. The tray sits on the washing machine with the siphon hanging over the laundry room sink.