Cardboard shim for loose tuning pin (piano)

[themaximillyan]

This is a cost-effective method of fixing a loose tuning pin. It avoids de-tuning adjacent strings, which can happen with methods that involve hammering tuning pins in.

First, turn the tuning pin enough to slacken the string coils. Then, using a narrow (but strong) screwdriver or an awl, lever the end of the string out of the tuning pin hole. (This point in the string is called the 'becket'). Lever against the tuning pin itself to prise the string out.

Now unscrew the tuning pin completely, leaving the string and coils in place. From some corrugated cardboard about 2mm or 3mm thick, cut a piece 20mm by 50mm. Insert this strip into the tuning pin hole (It may be helpful to curve the cardboard round a screwdriver shaft first, to make it easier to insert into the tuning pin hole). Firmly start the tuning pin into the hole, with the cardboard shim in place. Carefully turn the tuning pin into the hole, going quite slowly so as to avoid a build-up of heat. Turn the pin all the way in, to the same level as before.

Carefully insert the end of the string (the 'becket') back into the tuning pin hole, using suitable pliers. Make sure that the string coils are kept tight, using a stringing hook or a screwdriver.

Tune the string to pitch. The cardboard shim method will keep the pin tight for years and does not involve glue.
This English translation kindly made Scotland  technician David Boyce

[themaximillyan]

The main advantage of Jim's method of shimming

is the use of a thin sheet of veneer, which allows for minimal material removal from the pinblock hole. This can be especially useful when the hole is already worn or enlarged. The veneer can be precisely cut to fit the exact size of the hole, allowing for a more accurate repair there.

On the other hand, Max's method of shimming

using corrugated cardboard or paper offers a cost-effective solution that is easy to obtain. It can work well for many pinblock holes, and the material can be built up in layers to achieve the desired thickness. Additionally, the use of cardboard or paper can minimize damage to the surface of the pinblock hole.

Overall, both methods have their advantages and can work well in different situations. The use of cardboard or paper may be more versatile and cost-effective, but the use of veneer may be preferable when a high level of precision is required. It is important to choose the method and materials that are appropriate for the specific piano's repair needed.