These counter flap hinges I'm using for the flaps on the new cratch table are lovely, but what a pain they are to install. The idea is that they will allow the side table flaps to fold over flat against the main part of the table but will lie flush when the table is open. So to get them flush with the table surface I have to carefully cut out one layer of ply in the plywood. Well two actually because there is a wafer thin outer veneer layer. This veneer is very fragile and splits easily so the problem has been how to do the cutout without fraying the edges of the veneer.
Wisely, I worked on practice pieces first and eventually succeeded by using masking tape to protect the edges. However that was the least of the problems. After the first layer for the hinge plate, you have to do a further deeper step to accommodate the hinge pin barrels, then a hole to let the central bass joining piece swing.
Plywood, once you get inside it is nasty. It splits and cracks easily yet is quite hard because of the embedded glue. This test piece took me a couple of hours to get right and on the real thing I have to do eight of them, two for each of the four hinges. However they should be a lot quicker now I know what to do, but if I mess one up I'll have to cut a new piece of wood and start all over again.