Lots of people think that the double-chambered pipe is new; either a new fad or function. 'Tain't so. The traditional calabash is a double-chambered pipe. One of the best smokers in my opinion. It is unfortunately cumbersome to carry and smoke - definitely a sit-in-a-chair kind of pipe. What I attempt with this design of the double-chambered pipe is a new application of an old idea. I want to marry the convenience of the standard briar pipe with the smoking characteristics of the calabash.
If you examine the engineering of a calabash, you find a tobacco chamber, followed by a short draft hole, then a large air chamber, and finally another draft hole. The key is the large air chamber. I suspect that there is an upper limit, but for practical purposes, the larger the chamber the better it functions. The double-chambered pipes offered here are structured the same as the calabash.
The air chamber serves three functions.
First, it provides time and space for the smoke to cool. I measured the size of the air chamber in several calabash and found that 50 to 80 cubic centimeters (3.6 to 5 cubic inches) was typical. It is the internal surface area, and sometimes the material used, which cools the smoke. 65 cubic centimeters is equal to a 205 centimeter long church warden.
Second, moisture precipitates out of the smoke while in the air chamber. The turbulence of the smoke's passage through the second chamber and the drop in temperature causes moisture to precipitate. Pipes with small chambers, like the Peterson, precipitate some moisture due to the air turbulence, but lack the surface area for cooling.
Lastly, the moisture precipitated from the smoke has to go somewhere. The caviler or hunter shapes probably collect moisture about as well as any pipe. In the double-chambered pipe, the draft holes are well off the bottom of the chamber. Truth be told, when I was first making the pipe, I was VERY careful to keep the draft holes high because I was afraid of the "gurgle." Turns out that rarely more than a light dew forms on the inside of the chamber during a smoke.
A final consideration to the design is the method for attaching a stem. Wood moves in response to moisture and temperature. That means that any friction joint, or glue joint between different materials, is likely to fail over time. I use a threaded cap on the end of the air chamber. A thread can be used when the pipe is hot or wet. All that happens is the cap will thread on further or a little less far in response to changes in the wood. A well made threaded joint will last as long as the pipe will.
However, because the cap at the end of the chamber may change how far it tightens, the cap and stem can not be made as one piece. Thus, the cap screws into the pipe, and the stem is attached to the cap with an adjustable mortice and tenon joint.
Cleaning the pipe
I wind a paper towel into the chamber, spin the pipe around a couple of times, and pull the paper towel back out. Wipe off the inside of the cap, and then put a pipe cleaner through the draft hole and stem.
If you examine the engineering of a calabash, you find a tobacco chamber, followed by a short draft hole, then a large air chamber, and finally another draft hole. The key is the large air chamber. I suspect that there is an upper limit, but for practical purposes, the larger the chamber the better it functions. The double-chambered pipes offered here are structured the same as the calabash.
A final consideration to the design is the method for attaching a stem. Wood moves in response to moisture and temperature. That means that any friction joint, or glue joint between different materials, is likely to fail over time. I use a threaded cap on the end of the air chamber. A thread can be used when the pipe is hot or wet. All that happens is the cap will thread on further or a little less far in response to changes in the wood. A well made threaded joint will last as long as the pipe will.