Some notes on tuning

I got some basic tools in on Friday so I'm able to start messing with the piano a little more.  Tuning pins come in different sizes, and they only differ by a few thousandths of an inch.  I ordered a #2 size tuning wrench because #2 is "the most common size found on virtually all pianos produced worldwide over the last 100 years." The wrench worked but it wasn't a great fit.  This piano came with a broken (missing) treble string, so I removed one of the tuning pins for that string and measured it.

The size of 2/0 pins is 0.282in, and 1/0 is 0.276.  So, for whatever reason, my 1918 Weber baby grand piano came with size 1/0 pins instead of the standard 2/0.  From this, I can conclude a few things.  Typically if you restring a piano without building a new pinblock (the block of wood the tuning pins are threaded into), you increase the size of the pins to make them a little tighter.  Since this piano has 1/0 pins, it is probably safe to assume that these are the original strings and tuning pins.  

Next up, the pinblock.  Tuning pins are threaded into a block of wood called the pinblock.  Over time, the holes wear down and the pins get looser.  You can measure pin tightness with a torque wrench.  I ordered a tuning pin sized socket for my torque wrench and checked the torque required to turn a few of the pins.  Tuning pins should take somewhere around 90-110 in-lbs of torque to turn, as high as 140 still being acceptable.  More than is considered too tight making it difficult to tune.  Any less than that, and you have a piano that won't stay in tune for very long.  Long story short, mine measured in the 50-80 in-lb range.  That's bad, but it gets worse.

These dates and words in this picture tell a story.  Some time in the early 80's, the owner this piano wanted to start using it again.  The dates may correspond to having it tuned, but the part that has major implications here is the word PinTite.  When a piano won't stay in tune, and it isn't worth the time or money to restring with thicker tuning pins, you can apply something called pin tightener around the pins.  It is a liquid that absorbs into the wood, and causes the wood to absorb moisture, which then swells, tightening around the tuning pin.  Sounds great, but it is basically a short-term fix that can never be undone.  It may help for a few years, but after a while, the pin block ends up in worse shape than before and needs to be replaced.  Replacing a pinblock is no easy task, but if done well, will last for another 40-50 years.  It also requires all new strings and new tuning pins.  Basically, by the time I'm done, I'll have taken apart most of the piano and rebuilt it.  The good news is that most cleaning and repair operations are a lot easier once all of the strings are removed, so I'm not even attempting to do anything major until then.