I am looking to build a snorkel to help protect from the dust but I have never worked with PVC pipe before. What is the easiest method to measure and figure out what bends and diameter I need without buying a bunch of random peices and trying them?
Not difficult at all really. 4 foot pc of 2" pvc. 2 90's and 1 22 degree elbows plus a 2" femco fitting and your good to go. Just twist fittings around till you get the right configuration, mark a line with magic marker on all connections so you know how to put it back together before gluing up.
Exactly what Hib said. 2" Fernco and you're off and running. Be sure to use 2" pipe and not 1 1/2", reducing the size will starve it for air. Black pantyhose on the tip will work as a prefilter too.