I just got off of the phone with a trombonist who had a stuck leadpipe. Since I’ve answered this question numerous times on the phone and in emails, I thought, “why not post this info in our new blog?”
The first step is to use your mouthpiece to get the leadpipe un-stuck. For many, this will be the end of the dilemma. However, it is possible to get the mouthpiece stuck in the leadpipe. If this happens, gently tap the leadpipe nut knurling away from the mouthpiece with a Delrin or Rawhide hammer. Hold the mouthpiece and leadpipe in your left hand so that when the pipe comes free it won’t fall to the ground. You will need to tap the leadpipe gently while rotating the mouthpiece/leadpipe in your left hand. It might take a few minutes, but the mouthpiece will always break free from the leadpipe.
For those really stuck leadpipes:
Take a set of adjustable pliers and wrap either cloth or tape around the jaws. This will prevent them from scoring the leadpipe or instrument. Hold only the slide and grip the leadpipe nut knurling with the covered jaws of the pliers. Turn firmly to the left and then remove the leadpipe.
Once the leadpipe is removed take a small amount of tuning slide grease and apply it to the leadpipe end and threads. This will help keep the pipe free from corrosion. If your leadpipe is perpetually stuck, consider purchasing a small rubber “o-ring” from a hardware store. Put the ring on the leadpipe just below the nut. This will definitely prevent the leadpipe from ever getting stuck again.