I'm building a mobile cabinet with flip-up wings for my miter saw. The wings are connected to the cabinet body with piano hinges. Based on my limited experience with piano hinges and the fact that no matter how much effort and time I put into connecting the hinges, I'm worried the top of the wing and the top of the cabinet won't line up. Maybe I'm being pessimistic, but piano hinge alignment hasn't been an easy task (nor has connection, the screws provided with the hinges suck). Any suggestions? Is there a jig or fixture that makes the piano hinge installation foolproof (for fools like me)?
I agree with you the screws that come with most of the packaged hinges are junk. I use a #4 or #5 FH phillips x 1/2" screws I buy in bulk. The difference in size depends on the size of the hinge and the countersink provided.
If you can lay out both members receiving the hinge at the same time, to get the hinge leaves aligned properly, that will set where the knuckle (barrel) will be. I use a fine point pencil and mark out the holes and use an awl to pinpoint the screw point. Piloting the hole is necessary. After piloting, I use a countersink to slightly chamfer the hole. This makes for easy and clean seating of the screw through the hinge.
I don't use a combo countersink/drill, as they aren't precise enough. Using an awl to center punch the marked hole works better than the spring loaded punches or Vix bits.
When installing the hinge, I usually only put in a screw near the ends and in the middle to just check alignment, fit, and movement. If all is well, I'll mark, punch, and drill the rest of the holes. It's necessary to pilot a straight hole, as any cant to the screw when installing may allow the edge of the head to hit the opposing hinge leaf.