Step 4: Step 2: Modifying the Propane Regulator
The existing bernzomatic propane torch doesn't provide enough flow for a tube of this size. I have found that boring the nozzle out to 1/16" with the drill press adequately increases the flow.
(As of note... we finally happened upon this method after numerous failures. Building your own propane regulator we found out is a VERY BAD idea.)