It will also make it very difficult to fill unless you cut a hole in the top for that, which will let in more dirt/poop and like jmagill said - keep it from working properly.
I don't know what they call them but when I used to use a waterer like that, I used a pipe securing ring from the hardware store. They have a screw-in tightener on the side so I was able to make it very tight and it worked great. I tied wire to each side and it held up like a charm. I really...