@Sime:
I recently upgraded to a bigger board, but before that I was thinking about using those thin business card sized fridge magnets (the kind that some businesses give away for free) to hold the board in place. I was going to cut 6 of them in half and glue them to the back of the boards like in this diagram (the black rectangles are the magnet halves in case it wasn’t obvious).
I was then going to use 6 more (uncut) magnets as joiners, connecting the boards.
I think would help stop warping at the edges where the magnets are so you can easily slide navies or armies over those sections without having to pick up the navies/armies and place them on the other side of the edge.
Although I didn’t have a pretty picture, I had essentially the same idea.
http://www.axisandallies.org/forums/index.php?topic=12827.15
I’m not exactly sure how refrigerator magnets work, but in general when you break a magnet with a north and south pole into two pieces you get two new magnets (each with their own north and south pole). This is because there are no magnetic monopoles as a result of one of Maxwell’s equations $\nabla\cdot\vec{B}=0$. If refrigerator magnets work like this, then only half of each magnet that is cut in half will be attracted to the un-cut magnet holding the board together; the other half will repel. However, I don’t think this is how refrigerator magnets work. I think they’re made up of a bunch of little dipoles and your idea should work fine. However, might a rigid, thin strip of a ferromagnetic metal such as iron or steel serve as a better spine(s)?
