Hi, Love the blog!
I was wondering how you sealed the seams between the PVC sheets and the screw/rivet attachment points to the wall. You mention the gutter at the bottom but don't really say how it was made or what it looks like. These details would really help me.
The seams were sealed with silicone. So were the screws I believe. Just a dab on the screw head. Our basin was made from PVC ( a material I wouldn't use again due to it's environmental impact). It was glued together with special glue. The shape is quite unusual because it ducks under our cabinet at one point. Also it's curved to match the shape of the wall. Most basins will be much simpler.