Last April (Fool’s) 1st I posted (chuckle! chuckle!) advertising my “WHBIT Replacement Tuning Pin Holes” which promised to magically repair the loose tuning pins that render accurate tuning an exercise in frustration. The WHIBIT hole idea is preposterous but in most cases the frustration is real. In the “Old black autoharp” topic I have described shimming pins to make them tighter but what can you do when taking the instrument apart isn’t an immediate option?
As a piano technician encountering loose pins, I have had many opportunities to “save” instruments where proper repair or rebuilding has not been an option because of expense or time. These same procedures can be applied to the zither pins of an autoharp or hammered dulcimer to extend the life of the instrument until a better alternative can be found. In many cases , a liquid pin treatment has had permanent success.
Homemade pin block restorer
Very old piano tuner correspondence school texts implore students to guard this trade secret formula. Sorry! but here it is. Mix well a 50/50 solution of isopropyl alcohol and glycerin. Use a dropper to apply as much to the base of the pins as they will absorb. Wait a week and tune. The alcohol eventually evaporates and the glycerin remains. Being hygroscopic, the glycerin absorbs moisture from the air which swells the wood making the pins tighter. For years this was all we had and it actually works quite well improving with time. It is messy and can cause corrosion on pins and strings.
Sold only to piano techs, it is an improvement over the homemade stuff in that it won’t cause rust and you can tune in 20 minutes or so.
Cyanoacrylate (super) glue
CA glue is amazing…and dangerous! The water thin variety available from hobby shops and hardware stores has really changed how we tighten tuning pins. After applying a few drops to the base of the pin, it wicks into the porous wood fibers making the surrounding wood harder and tighter but doesn’t glue the pin in a solid position. At the piano it works pretty much instantly allowing me to complete my tuning without having to schedule an expensive return visit. While not as effective as other methods, CA can be applied without removing anything and in many cases can be a permanent fix.
…and dangerous! CA glue’s speedy chemical reaction gets extremely hot and the smoke-like gas it sometimes produces is a nasty irritant to eyes and respiration. Sometimes the surfaces to be glued seem to absorb a lot of glue that travels rapidly through invisible seams and cracks to emerge somewhere far away. Without care, it is even possible to glue an autoharp to your forehead! To your forehead… don’t ask!
So, carefully consider the risks involved and the extent of the problem before trying CA glue on your instrument. By all means read and follow the safety warnings. Ventilate the area properly. Use a sharp bottle tip or a specially made pipette to accurately apply the CA keeping in mind that unsightly runs cannot be easily removed. Resist the urge to wipe off an excess drop with your finger and be sure to have CA glue remover at hand. Try the worst pin first and evaluate its improvement before going on. With care you can make a measurable difference in your instrument’s ability to hold tune.