: Bike tube should work, but your tolerances might be a little tighter

Tolerances might be tighter? Mmm. 'Cause I'm farther North? No, no. Mm. Maybe the quality of my work is lacking, sounds more like it! Looks more like it, too! Sigh. But, I sealed up the final gaps with silicon sealant - that worked really well!

: How about a flat-bottomed PVC end cap?

Ah. Sure... I'll have to find a better/bigger hardware store. Oh! How I hate to have to frequent the Despot! It's just that the selection is really limited in the little stores around here!

: Cut it bigger with a jigsaw and file it to shape.

Hmm. I cut 'em bigger and then tried to sand them to shape with a belt sander. It didn't go as well as it could have... Method: I cut little pieces of dowel and then screwed the discs to these shafts which I then inserted in my drill. The shafts had a nasty habit of flying apart... Or the screws would come loose or any number of other silly problems. I'm sure I'd be better off with thinner plastic but I was just using what was on hand - 1/4" plexi. (The same plexi I used for making my seat. Now -that- worked really well!)

: I think you really want the plunger rubber disc to be bigger than the
: diameter for a seal...however, drilling holes in that disc is a
: super idea, and would really improve flow. In fact, I'm going to do that
: to my own pumps...it never really was the "Baker" pump as much
: as a small "Dave Carnell" pump...but now it has to be the
: Shawn/Charles pump!!!

Ah! I'm blushing! Anyway, I'm gonna have to work on it a bit more - after I find some lighter pipe!

: Sounds like a great ale to drink after a cold day's paddling!

We'll see! It's so different from anything I've ever made! In the meantime I'll just stick with my red ale (yum!).

cheers!
c