I get questions about how to separate backbore lower shanks from upper backbores components, and tops from backbores, so I thought it might be helpful to post some info on how to do it with duct tape. There are other ways to do this, but this way will remove even stubborn tops, uses no tools, and cannot damage the mouthpiece. I keep a roll of tape in the woodshed for this.
To separate the lower shank from the upper backbore component in order to switch it to a different length for gap adjustment:
1. Apply duct tape to the shank as shown in the photo below. It must wrap in this direction.
2. Place 3 wraps of tape around it.
3. Place the taped shank along your fingers.
4. Place 3 wraps of tape around your fingers and the shank.
5. Grab the top segment of the backbore and twist it off. If you cannot get a good grip on the top segment of the backbore put a wrap of duct tape around it.
If the shank is really stuck instead of taping it to your fingers you can tape it to the handle of a screw driver for more leverage. This is shown in the photos of removing a stuck top below.
To remove a top from a backbore:
1. Attach duct tape to backbore as shown.
2. Place 3 wraps of tape around backbore. It must wrap in this direction, shown more clearly in the photo of the shank above.
3. Tape the backbore to your fingers as shown above, or to the handle of a screw driver if it is really stuck. Fingers are usually fine.
4. Place 3 wraps of tape around both.
5. For a better grip on the top you can place a wrap of tape around it. This is optional.
6. Grab the top and twist off.
If the tape tears you should put more wraps around the backbore and your fingers (or screw driver handle), or use better tape. What would we do without duct tape?