WhiteScythe

I've heard a lot of things when it comes to trying to waterlog a chiseled block, but the best I've got is chiseling out a block so it only has 1 pixel thick walls and an open top, I try waterlogging it and it doesn't work, but as soon as I put a big enough hole in the bottom it lets me. What's up with that? I want a basin, not a vertical pipe.