Step 3: A safety note
The whole process of this build revolves around heating PVC pipe until it is pliable and then squishing it. PCV (That's Poly-Vinyl Chloride, for those impressed by big words), is pretty toxic stuff when you heat it. I don't actually know what is produced with it is heated, but it smells horrible and gives me a terrible headache. I don't know if there are any long-term effects, but i would be willing to bet that breathing the fumes for any length of time will definitely make you more stupid.
So, DO THIS IN AN EXTREMELY WELL VENTILATED AREA!!! Preferably outside in a windy area, and wearing a respirator for extra safety. Basically, if you smell the odor of heated PVC, go some where more ventilated.