How to Fix Loose Tuning Pins

Here’s what to do when the tuner complains you have a bad pin block and she tells you your piano’s dying because the pinblock –  due to fluctuating humidity – is so dried out the pins got so loose that the strings pop out of tune, or that they’re impossible to fine tune.
Don’t worry.
Get some 2-oz bottles of thinnest superglue with an applicator cap.  You’ll probably use two, maybe even three.  And borrow a brute or two to help tilt the piano on its back.  
Call around piano shops and see if one will rent you a piano tilt truck.  Probably they won’t!  You’ll have to lay the piano flat on its back, which means letting the top end rest on a 2×4 so you can get your hands under the piano when it’s ready to stand back up.  
Borrow or buy a respirator good enough to keep superglue fumes from clogging ye lungs.  
Important: 1) clean the pinblock thoroughly before applying glue, otherwise you’ll be permanently gluing old dog hairs and dust to the block.  2) super important: go back over the pins until they don’t soak up any more glue, and do not spray the NCF accelerator.  If you let the glue dry before it has a chance to wick into the holes you’ll seal the holes prematurely and no glue will get in far enough to make enough difference. 
Take a bottle, snip the applicator cap and apply several drops of glue around the base of the tuning pin until the capillary action stops.  Try not to make a mess of it, but it does dry clear so you can be a bit generous with the application.  Do this in groups of 15 pins. Go back a second time and add a few more drops proceeding onto a new group.  Let it soak in an hour or two before standing it up. This is a smelly and time-consuming process but it will very likely save your piano’s ass.