Here is my humble attempt at making my own folding goban. It is extremely cheap (okay, I got the board for free), relatively easy to make (if I was able to do it, it must have been easy) and the end result is quite passable.
It all started when I found this locker door literally on the street. I was thinking of making a folding goban for some time and was looking for a suitable board. When I saw this one, I knew it would be perfect.
As you can see there are holes for mounting hinges on the back side, which was trully a pity, as it was smooth, while the other one had water-damaged semi-peeled paint and very rough surface.
Yea and verily, 'twas a hard cutting job with this little makeshift saw. What's worse, it turned out that the board is not made of pressed particles, but of slaths of solid wood glued together and covered with several thin plywood strata.
The next step (which remained undocumented) was to peel of the paint and try to smooth the surface with rough sanding paper. It was a very hard job and not entirely successful, as the removal of the paint left some ugly craters on the board.
On the left side you can notice the holes that once held the handle. I hammered some toothpicks to fill them, before applying the wood imitation folio.
Here you can see the hinges on the already cut board. As the cut was not regular, after some trial and error, I managed to mount the hinges bent in such special way, as to have a stable surface while the board is unfolded.
The places where the hinges are fixed on the side of the boards were slightly carved (actually I did this with sand paper) so the two halves don't get separated too much by the thickness of the hinges when the board is unfolded.
Here is the unfolded board, with the wood imitation folio applied so that the grains 'connect' the two players. I forgot what tree this is an imitation of, just go at the store and choose the most appropriate texture.
Be careful not to leave air bubbles and fold the folio over the edges so the sides of the board are also covered. I've left the inner surface as it was, but maybe at some point I will fill those ugly hinge-holes and paste another sheet of folio, maybe to have a 13x13 board on the other side or something.
Here is the board folded, you can see how the bent hinges makes the two halves misalligned. Who cares, they're prefect when unfolded ;)
Here is the poorly shot other side, but at least you can see that the folio covers well the sides of the board. You have to be very careful when folding the folio over the short edges of the board, where it has to be cut with a sharp model knife as not to leave and edge, otherwise it may later get unglued and ugly.
After several hours of work (most of which were rests, it is a hell of an unnerving task) and with the help of a long ruler and permanent marker pen for CDs I managed to draw the grid.
All this should convince you that you need absolutely no woodworking skills or special instruments to make your own goban, be it folding or not, just a little patience and some very cheap materials.