Vac Stack
From Melting Pot Wiki
A technique for making colored line tubing.
The vac stack is an evolved method of the stick stack. the setup is done while cold, and a clear tube which is sealed on one end is used as the core. the core is surrounded by colored rods, then sleeved with a larger clear tube. once hot, a vacuum pump or shop vac is connected to the outer sleeve and is used to suck out the air between layers.
