Jami
In countries like Norway, Sweden and Finland, it should be easy to find a straight spruce tree for a mast.
Now I looked up the The Cambered Panel Junk Rig, Chapter six to find the needed diameter of a hollow wooden mast. First, I found the fake sale area to give a SA/disp =14:
Fake SA =18.38sqm.
Putting this and a LAP=8.3m into the PJR formula produced a resulting mast diametre
D=19.8cm.
Even by twisting the PJR formula, the masts come out on the heavy side.
Another method:
I also have another ‘home-made’ formula based one the estimated righting moment of the boat and the bending strength of a (hollow) wooden pole. Since wood varies in strength, I have put in a needed breaking strength 3 times the estimated righting moment of the boat.
The result was D=17.36cm, or say 18cm.
I know that Jester used a mast, which was about 18.2cm. This was much taller than this one and Jester was also heavier than the Gallion 22, so maybe a diameters of 17cm would be a better choice for the coastal waters around Finland. I surely would reckon 18cm to be plenty, even if you have the North Sea in mind.
Arne
PS: I haven’t double-checked my calculations.