Recently purchased this vessel type sink: http://www.signaturehardware.com/product14433
It is described as having an overflow hole, which it appears to have. The overflow hole leads to a "channel" within the wall of the sink which leads down to the drain hole in the bottom of the sink. However, on the very bottom of the sink there are two dime-sized hole (1 on either side of the drain hole) which allow any water entering the overflow hole to exit the overflow channel before reaching the drain. Am I supposed to plug these two holes with something and if so what? If I don't plug them, the overflow does not function as such. Or is the whole system only supposed to function as a venting system? Thanks in advance for any help.