Last week I posted on several online forums that I was looking for a couple of threaded stems to fit two bowls that I had here. Both needed threaded tenon stems. No one seemed to have any that would fit. So I set them aside thinking it might be a long wait before I came across any stems. This afternoon I was sitting at my desk and picked up the two pipes and turned them over in my hands to look them over. They both were pretty decent bowls, each having only one fill that would not be an issue. I made a decision to drill out the threads on the bent pipe and see if I could fit a push stem to the shank. I have done that before and it worked quite well so there was no reason to think that it would not work this time. You just have to start with a drill bit roughly the same size as that mortise and work slowly upward until the mortise is ready for the push stem tenon.
I set up my cordless drill, inserted the appropriate bit and began the process of drilling out the insert. I worked through three drill bits slowly turning them into the aluminum insert. I notice at one point that the insert seemed to shift when I reversed the drill bit out of the shank. That got me wondering about the way the insert was held in place in the shank. The odds were very high that the inserts were reverse-threaded into the shanks of the pipes. I decided to stop drilling and test my hypothesis.
I positioned a pair of pliers on the aluminum end of the shank, being careful to only put them on the metal and not the briar. I did not want to damage the briar of the shank and make more work for myself. Once I had them positioned I carefully turned the insert counterclockwise. I was careful to hold the briar shank tightly in hand so as not to create stress on the shank and snap the briar (having experienced that in the past). After initial resistance the insert turned slowly and gradually I was able to turn it out of the shank.
I followed the same procedure with the second bowl – a straight shank billiard style with a metal mortise insert. It came out even more easily. I had two bowls that could now be restemmed with push tenon replacement stems. This was yet another great trick to add to the tool kit as it provides a new way of dealing with these bowls with threaded mortise inserts.