About six months ago, I acquired an older estate Peterson 4S Deluxe System pipe from Chuck Levi at Iwan Ries. He knows that I collect Petersons and when I walked in, he showed me a tray of unrestored Petes. This was one of three that I brought home with me. Two were system pipes and both lacked their condensers. I had a couple different sizes of condensers in my repair kit and both were too small. The larger of the two condensers was a current model which has M6 1.0 threads and was just barely too small. The stem seemed to have 1/4-28 threads.
I first tried writing to Peterson and was told that they no longer had any of those older condensers and, no, I couldn't buy a new stem without sending the pipe to them. I thought about enlarging the socket, gluing in a piece of Delrin, then tapping M6 1.0 threads but then came up with a simpler solution...a threaded insert. I landed on a variation of a threaded insert called a helicoil. These are mostly intended for thread repair or reinforcement, but since the diameter of an M6 thread is so close to the 1/4"-28 threads in the stem, it seemed like the perfect solution. At $12 USD, these kits are pretty inexpensive, especially compared to buying a whole new stem. It took me longer to select the kit to buy than to install the helicoil, which was about five minutes.
The kit includes the drill bit, a very slightly oversized M6-1.0 tap, a couple simple helicoil-specific tools and 30 helicoils, which are much less bulky than a regular threaded insert. I barely enlarged the hole with the drill, cut the new threads (VERY easy in Vulcanite), inserted the helicoil with the included tool, then snapped off the portion of the helicoil that's used only during insertion. And voila, the condenser fit perfectly.
P.S. This 4S is stamped with an upside-down 7 in front of the "4S". It could it be an "L"? I understand from Mark Irwin that he has seen a few other such stamps, but does not know what it signified.
Also, this older stem is very comfortable and noticeably thinner at the button. My suspicion is that it was hand cut, and is influenced by the fact that the hole in the p-lip is obviously off-center.
I first tried writing to Peterson and was told that they no longer had any of those older condensers and, no, I couldn't buy a new stem without sending the pipe to them. I thought about enlarging the socket, gluing in a piece of Delrin, then tapping M6 1.0 threads but then came up with a simpler solution...a threaded insert. I landed on a variation of a threaded insert called a helicoil. These are mostly intended for thread repair or reinforcement, but since the diameter of an M6 thread is so close to the 1/4"-28 threads in the stem, it seemed like the perfect solution. At $12 USD, these kits are pretty inexpensive, especially compared to buying a whole new stem. It took me longer to select the kit to buy than to install the helicoil, which was about five minutes.
The kit includes the drill bit, a very slightly oversized M6-1.0 tap, a couple simple helicoil-specific tools and 30 helicoils, which are much less bulky than a regular threaded insert. I barely enlarged the hole with the drill, cut the new threads (VERY easy in Vulcanite), inserted the helicoil with the included tool, then snapped off the portion of the helicoil that's used only during insertion. And voila, the condenser fit perfectly.
P.S. This 4S is stamped with an upside-down 7 in front of the "4S". It could it be an "L"? I understand from Mark Irwin that he has seen a few other such stamps, but does not know what it signified.
Also, this older stem is very comfortable and noticeably thinner at the button. My suspicion is that it was hand cut, and is influenced by the fact that the hole in the p-lip is obviously off-center.
