Sealing cracks

I was browsing a second hand shop today and I came across a wooden recorder. It had two large cracks in the headjoint and it was impossible to get a not out of it - presumably due to air leaking out of the head.

This has got me thinking, how can cracks on wooden instruments be sealed? What is needed to seal it and how should the sealing be done?

I know this isn’t a flute question, but I assume many people with wooden flutes will need to deal with similar problems, so I thought I would ask here… :smiley:

A qualified repairer will glue and pin major cracks. Minor cracks just glue. There is often clamping involved to pull the instrument back to its correct size and shape. If a crack goes through a tonehole that is keyed, the key pad won’t seal properly, and the tonehole will have to be replaced.

If you search YouTube for clarinet crack repairs you should find a few videos showing the process. I found the pinning process especially interesting.