These are PVC:
This is a Bad Azz Myzztic:
https://www.rocketryforum.com/showthread.php?52905-Bad-Azz-Myzztic&highlight=Myzztic
This one was inspired by the Myzztic:
https://www.rocketryforum.com/showthread.php?56720-Introducing-NUCLEAR-FALLOUT
The more I work with PVC, the more I like it. Its tough so smaller chutes will do the job. Its chemical resistant so if you mess up a paint job, you can wash it off with lacquer thinner and start over. It sands smooth, and its easy to get an outstanding finish.
Not all PVC is created equal. In the smaller diameters, the inside and outside texture of the pipe is fairly equal among the manufacturers. As you move up in size this is not the case. So, if youre going for a great finish, find smooth pipe. Yes PVC will sand, but its also abrasion resistant so it sands very slowly.
In addition, youll need the thin wall pipe. This pipe is not rated as a pressure pipe, and is commonly referred to as drain pipe. The pressure pipe is much thicker and far heavier.
Another thing to keep in mind is that PVC pipe is measured on the ID. As such, standard rocket parts will not adapt. So If youre going to work with PVC, its a good idea to have a lathe and a dividing head, or know someone who does. This will pay dividends when it comes to making retainers, nose cones, and centering rings.
Im thinking all of my scratch builds going forward will be PVC. Unfortunately, this restricts me to 3 inch, as this is the safe limit of my lathe.