A Pipe’s Airflow Problems - Part 1

What do you do when your pipe, even after careful cleaning, doesn’t smoke as well as it did when you got it the first time.
There are a few techniques you can try at home to bring your new or old pipe to how it smoked before.
Before we begin there a few rules of thumb concerning any Do-it-yourself repairs. First, if you are not sure send it to a professional, inexperience may sometimes lead to disaster. Second, always use common sense, never use force and always doing a little at a time. And finally, start with the least invasive approach, like running pipe cleaners.

Checking for airflow problems : - Constriction of airflow in the draft hole from bowl to bit is one of the most common problem. Blow through the pipe to determine if the draw is constricted. Thin pitched sounds or whistled are indicators of blockage. Next, blow through stem and stummel separately. This will determine where there is a blockage. Running a pipe cleaner from the stummel (bowl and shank) to the mortise (exit at end of shank) and feeling where it catches will many times tell you where you problem lies.
The throat, where the bowl hole begins would be the first area to be examined. Because of the minimum size of the hole in the throat, when the cake built up, it can also build-up around the throat slowly closing the airflow, diminishing good airflow, which most of the time is not obviously noticeable.
The last solution for a choked throat, after bristled pipe cleaners, is a hand held drill, a dull one. Using the third rule of thumb, using the least invasive approach, start with a drill bit that is likely the smallest. This bit should slide through the shank. Increase the size of the bit until one will feel rather snug as you work it into the shank. Do not use this method if the bit feels tight in the air hole, you risk altering the original bore of the shank and even cracking it. In this case send it to a professional.
Having chosen the correct bit for the work ahead, carefully work it into the air hole toward the chamber. Do not apply pressure on the bit, it will work as you turn it. Observe the bit emerging inside the bowl , stop turning the moment it does. If you work the bit further into the bowl it can create an undesired trench into the floor of the chamber. As the bit appears inside the chamber, pieces from the cake should come out with it.
This technique will also work with shank that hasn’t seen proper cleaning for some time and re-establishes its original bore.

Next-Part 2: Problems with stems