SML: Moldable Plastic

[jAckY89]

I remember hearing someone talk about a plastic which when warmed by water
will become soft so you can shape it into anything you want. I was wondering
where you can get those because I want to make prototype cais. Can someone
be so kind to please tell me where to get such things or if there are places
where I can have a shop custom make mandrel bent plastic pipes or carbon
fiber pipes for me.