How to Make a Watertight Wood Joint, Without Using Glue or Sealants
This woodworker shows how to create a gasket with just wood! Using the expansion of the wood he is able to create a water tight box without modern materials. via core77:
Unless you have experience with traditional boatbuilding or making traditional Japanese sake cups, you may not realize you can join two pieces of wood together–with no glue or sealant–in such a way as to make the joint watertight. Here master woodworker Frank Klausz reveals the trick taught to him by his grandfather, fabricating a helpful tool out of materials you probably have lying around:
It is indeed a clever technique, exploiting the behavior of both wood and water, and this is the first time I’ve seen it demonstrated.