Man, I REALLY hate to make my first post a negative one. But, take that pipe outside and stomp on it until its pulverized. I am a sculpter/ artist. I mainly do F/X work and automotive/motorcycle sculpting.

The clay that you are using is a Polymer clay, Polymer=PVC=Plastic.
This stuff will do long term permanent damage.

Nice attempt, but please do some research on clays. Take a ceramics class and learn the right way behind your teachers back!!!

GOOD LUCK