how is a fab perc made?

Fab percs are made very carfully.  It is made just like any doughnut in glass, but a lot of t

can ssv tubing go bad?

Like anything over time, the product can become worn out.  After a lot of use, it may be hard to clean it.  If left out in the sunlight UV can also cause degradation.

Can you put Kief Pucks in the SSV?

Yes, but the keif will have to break down for good air flow.  It is also helpful to turn the heat up when doing this.  Even adding a little flower to help hold the keif is also good.