Pinblock Repair / Replace ??

A grand piano's pinblock is a tapered plank about 5' long and is comprised
of several layers of veneer, much like plywood. Tuning pins are driven into
the plank and held in place by friction. The strings are attached to the
tuning pins. When the block fails,the tuning pins become loose and the
strings lose their tension. The span of a pinblock is typically about
seventy-five years. Once it fails, it's gone....Gone - Gone - GONE!

Some technicians will employ a number of parlor tricks in an attempt to
extend its life, but the remedies are temporary at best. The most com-
mon technique is to apply a "Pin Tight" solution to the tuning pins with an
eye dropper. The solution is a hygroscopic compound that absorbs mois-
ture from the air. As a result, the pinblock swells like a sponge to grip the
tuning pins. Unfortunately, the moisture accelerates the deterioration of
the laminating glue of pinblock.

Another trick is to remove the tuning pin, stuff the hole with sandpaper
or emery cloth and reinsert the pin. The bad news is that the paper is too
thick and winds up acting like a wedge that splits the pinblock apart.
Instead of sand paper, a more expensive option is to use brass sleeves.
These last a little longer, but the brass is slippery, compared to wood
and the tuning pins don't hold well.

Now, the latest gimmick is pour a cyanoacrylate adhesive (Super Glue)
around the tuning pins in an attempt to glue them in place. All these
techniques wind up failing and leaving the pinblock worse than before.
It's a lot like trying to repair a blown tire with a can of "Fix a Flat".
You might limp successfully to the nearest service station, but I sure
wouldn't trust that tire on the Autobahns.

A repair that can be successful is repinning. The process involves removing
the old tuning pin, reaming the hole and inserting an oversize tuning pin.
Success is limited to the condition and manufacturing of the pinblock. Not
all pianos are created equal. An "Economy" piano will have an "Economy"
pinblock which might not last past the warranty period. A well made piano
might have previously been treated with the "Pin Tight".

The only solid remedy is to replace the pinblock. Since the strings are as
old as the block, replacing them as well will mean the total repair will last
another couple of generations.