I spend an inordinate amount of time discussing this with my fellow painters. With the new security restrictions on airplanes and the airlines trying to squeeze more money out of passengers with weight limits, traveling with a large amount of painting equipment is getting harder and harder.
I’ve never traveled with turpentine, or anything I felt was dangerous, yet I have still had equipment taken from me at airports. Often in big American airports, when I would have difficulty getting through the screening, just changing to another x-ray station would get me through. It seems to often be just the decision of one individual whether or not tubed oil paint is dangerous. Once I had an agent take all my hand ground paint because the tubes were unlabeled. When I protested that I had made them myself he said that I should make my own labels too. So I did. I named my brand ‘Safety Series’ and had labels professionally printed to fit my tubes. That worked until the 100ml rule, and now its just easier to send them in my baggage. My (non-flammable) medium goes in a shampoo bottle, the Canada balsam smells like conditioner anyways.
Turpentine can be bought almost everywhere. The problem many people have is that they go looking for ‘art supply stores’ rather than the ‘chemical shops’ where most people buy turpentine in countries without large numbers of oil painters.
On this trip I was hit with massive overweight fees both going out and coming back. Luckily I was able to talk them down both times. The smart thing to do these days is what all of my fellow painters did, which is put everything heavy (including the box-easel) into the biggest carry-on that you get away with. One even filled his jacket pockets with books and cameras and other heavy objects.
Overall I’ve had good luck with Airport security. If you try to make things easy for them, they are usually accommodating to the fact that we are not the average traveler.