Just a final question for now: once you finish manufacturing your tubs, do you run any kind of test to make sure they do not leak at all?
Actually, we never make tests filling up the tubs. And they never leak.
The reason is explained in this video:
The wood in the joints is compressed and once it absorbs water it will expand.
It is a kind of security seal. Once you start filling it for the first time, the corners planks will “melt” into one another.
I hope it is clear. Please let me know of any other questions.