DIY Condenser modification

If you’ve been companioning any of the high-grade Systems (DeLuxe, Premier, Pub & Handmade) for very long, you’ve undoubtedly run across a cleaning problem: getting your pipe cleaner all the way through the stem. I don’t have any Patent or IFS era high grades, so I don’t know if this was a problem way back then, but I do know that since the Éire era (c. 1937ff.) this has been the case: you push your pipe cleaner through the button and everything’s going fine until—wham!—it snags on the condenser (aka “chimney”). Typical Condenser Block I accepted the Condenser Block Situation as an opportunity to clean the tenon end of the stem so many years ago that I haven’t thought much about it until Stephen Wilson, CPG, began sending me emails last fall talking about a DIY fix. As he was still doing some R&D, I put off sharing his insights. Not long ago he wrote with his perfected technique, one that falls within the skill set of anyone who can hold and use a Dremel. Gary Hamilton, CPG, dropped by this week for coffee and a pipe, and as like Stephen he’s also an articulate and insightful science-minded Pete Geek, I shared Stephen’s DIY tutorial with him, asking him to help me understand and visualize the problem of how blockage at the System condenser arises in the first place.  Gary, you'll recall, already has quite a bit of experience thinking about tenons, as found in his work in Posts #322 and #290. Just to be clear--because like you I'm learning as I go-- we're not talking about the lengthened built-in tenon extension on the Standard System, which is technically not a condenser--that is, it doesn't condense moisture around it (as Shane Ireland explained several posts back).   THE PROBLEM Stephen: Nowadays I smoke Peterson bent System or DeLuxe System (including the Pub) pipes.  As you know, there is a bit of a challenge getting a pipe cleaner down the stem.  I have found that using Long’s Bristle cleaner works the best.  However, those pipes with the aluminum divertor screwed into the stem make it almost impossible to get the pipe cleaner past, due to the flat edge of the condenser [the part screwed up into the tenon airway] pointing away from the bowl. Taking a clue from Mark’s Post #236 post on reducing turbulence by chamfering the tenon into a cone, using a drill bit, I have done the same thing to the flat end of the aluminum condenser.  Now my pipe cleaners just glide right on in.  But first, some theory. What Mark has imprecisely called the “tenon extension” is  correctly understood as a “condenser.”  Yes, it does extend the tenon but that is not its primary purpose.  Over the last 130 years, many pipe makers have tried to incorporate something into their pipe to help control moisture and tongue bite.  Any scientist or engineer can report that one of the by-products of combustion (i.e. burning tobacco) is water. …