Wow. Never thought of that. I just sent my first international order to Canada from here in Alabama.
Just a thought - cargo holds in aircraft flying at 30,000+ feet are always cold and the temperature probably isn't that much different in winter than summer.
Pressurized planes, even the cargo and baggage areas are pressurized - so that the cabin/cargo area is in the equivalent of 5000 - 6000 ft even when flying at 35,000 ft. Used to have a watch with an altimeter based on air pressure. It was great to see us flying along at 35,000 ft and the pressure listed as 6000. And, While I am not an expert on this, the Inside temps of these holds are certainly not below freezing nor should they be above 90° - 95° at the most in the summer.
That said, humidity changes can have just as much effect and greater - as wild temp changes such as in a closed up hot car in the summer sun, or the cold of an unheated shed in Canadian winter. Humidity is decreased dramatically in long flights compared to the outside. This change in humidity in the plane is more dramatic than the changes in the temp in the cargo holds, IMHO.
I too have questions - was the wood stabilized, or was it cross cut, or soft wood, or was it just air dried? Green wood and air dried along with cross cut woods can change size dramatically with humidity changes unless they are well stabilized. Thin CA, and other finishes, do not penetrate all woods as deep as one might think. I went back and read - cocobolo, - cocobolo can crack due to heat and or humidity changes. I have had some rather fresh and green, and I have had some that was obviously dryer.
I once tried to dye some 1/16 in balsa wood and put it in a pressure pot in the dye and held a vac for 24 hours. Then I put pressure to it and held it for 24 hours, Removed it, let it dry for a week, cut it and it was still white in the middle. Some woods but not all, are resistant to simple finishes penetrating the wood enough to prevent contraction and expansion due to humidity swings along with abnormal temps.
