Worn balance rail holes

[Virgil]

I’m working on a 1973 Suitcase piano. The action is in good shape side to side but I have a lot of movement front to back. Almost 1/8 of an inch. I’ve been searching threads but haven’t seen anything relating to this. Has anyone run into this. Solutions?

[pianotuner steveo]

I've seen it on some acoustic pianos. There are no solutions for this that I'm aware of. You can't shrink the holes.

[Tim Hodges]

If they were really bad and you needed them fixing I've seen repairs where they've taken a notch out of the bottom of the key and glued / pinned a new section of wood and re-drilled the hole. It's a lot of effort but I'm sure you might find a piano workshop which could do the work.

[pianotuner steveo]

I didn't think of that, but it is a lot of work. You may want to experiment with one key to see if it is something you would want to proceed with. Good woodworking tools and skills are a must for this. You could use maple or top end pine for this. Your best bet would be to use wood meant for trim.

[Virgil]

I have thought of plugging the holes and redrilling. I have the tools and think I can do it. I was hoping someone might have a less labour intensive solution. Otherwise the action is in great shape. I wonder if this was caused by being carted around in the back of a truck. The wear is even on all 73 keys.

[pianotuner steveo]

I'm not sure if plugging and redrilling would last. The diameter is so small, the new wood may just splinter and fall out. Remember also, the hole gets larger and oblong towards the top of the key.

[sean]

I think that if you drilled a hole to install a plug, you would only want the plug at the bottom surface of the key.  Only the bottom 1/8" or 4mm grips the balance rail pin closely.  (Well, it doesn't grip, it is a loose fit, but it is tighter than the big slot in the key and the button.)  The slot at the top of the key button is 7/16" from front to back.  This oblong slot is 7/16" all the way down to the bottom 1/8" of the key.

Can you show us some photos of your keys?  Show us the round hole at the bottom of the key, and the slot at the top of the key as well.  If the hole at the bottom of the key has become enlarged, then the only reasonable explanation is that some insane owner thought that jamming needle-nose pliers in there to stretch the hole would give them some lighter or looser action.  This person should be hunted down and spanked.

If you have to plug these keys to make the repair, you will have to use a piece of wood that is large enough to provide enough surface to glue and be strong enough to survive the drilling and years of playing without cracking or popping loose.  Maybe test five keys at the treble end, and see how hateful the operation is.  If it becomes too much work, bite the bullet and buy a whole new set of keys?  Ouch.

I think that sawing a notch across the bottom of the keys will be easier than trying to drill out a hole for a round plug. 

Sean

[bourniplus]

If you have access to the book "Pianos inside out", a few solutions are given on page 237. One is cutting a notch and inserting a small hardwood strip where the hole has elongated.
My piano tuning mentor had a special drill bit machined which allows to drill a hole the width of the key, using the existing hole as a guide. Then this is filled with an insert that is made on a CNC machine. He was thinking of selling these as a kit, but for a single piano it would be pretty expensive.

[pianotuner steveo]

Yeah, I think that would be the way to go. I am guessing that the reason this doesn't really come up as a PTG topic, is that the acoustic pianos that could have this issue would likely be junky old spinets. Its not really worth the effort to do this repair on those. It would be unlikely to see this on a higher quality piano, (Yamaha,Steinway,Mason,etc) because the keysticks would be higher quality wood, not cheap basswood that you could break over your knee like most spinets.

I agree with Sean as to how this may have happened.