Thanks, Lee & Alan! I have both aluminum tape and 100% silicone caulk (leftover from assembling my ClearVue 1800). Sounds like sealing and tightening is a good task to do when everything is in place. Today/tonight's plan is to start on some blast-gates. After battling getting flex hose over the PVC trying various heat gun, soap & water, and clipping flex hose wire methods, I'm planning to go with Alan's approach of female connectors for end points (from the DC and into machine ports) and with male connections on the flex hose. That's a nice standard solution for a single shop and makes sense to me.

If I decide to make my own PVC "bell" creation plug, did you just glue up several pieces of MDF to get the 6" MDF blank for turning, Alan?