I have a customer who owns a Hubbard single manual that was purchased in the mid 90's. When it was new the tuning pins were very tight and jumpy making it a difficult process for him to tune. I tried it out back then and had a hard time as well. He lived with it as he was told by the folks at Hubbard it would settle in after a few years. I had no reason to contradict that statement at the time as I have seen harpsichords and pianos with this problem and they did settle in. This instrument did not. It still has tight and jumpy pins.
Off the top the only way I see to solve the problem is to remove the tuning pins and ream the holes. Obviously this could get tricky as I believe one can quickly overdo it. I am wondering what method of reaming to use. My guess is that it should be done by hand as power tools could make things go wrong with the slightest move. I have a good hand chuck but I'm wondering if there are sets of reamers that would work well for the job or will the correct drill bit work just as well?
Any thoughts, ideas or experiences to share?
Can you wrench the pins back and forth a few times to use the pin as a reamer? Might it weaken the pins?
One option is to take a wire size bit (in the #15 - #9 area) and first see what size will go easily in and out, then move up to one that will remove a bit of material. Put it in a pin vise of some sort, and simply ream up and down, with the idea of mostly cleaning out gunk and removing glaze from the sides of the holes.
If I were going to actually ream, I'd get straight flute reamers from McMaster-Carr. The question would be what size, and that could only really be found out by experiment, with the bits (above) providing information. My Hubbard pins measure about .197". McMaster has .180", .1865" and .1885 that might be a good place to start (maybe others as well, as they have different sizes listed under different categories). They are around $15 - $20, so buying a few to experiment with would not be unreasonable. I'm not sure what size Hubbard uses to drill (my kit manual doesn't list it, as the block was already drilled). Again, I'd probably use a pin vise or the like (eg, I have a couple drill chucks I replaced or salvaged, that work pretty well for this purpose).
A further option is to apply powdered rosin, that can be had from sports stores. I haven't yet got around to experimenting with that on jumpy piano pins (maybe this summer), but others have reported success. A pipe cleaner, impregnated and run up and down each hole, for application.
Pull a pin and mic it. How much smaller should the hole in the block be for proper torque?
Thanks Jon & Fred for the replies! I suspect that after all these years turning the pin back and forth will not produce great results. I suspect that it is a combination of the hole being too tight and glazing so I will go with reaming first. It has been many years since I tried powdered rosin on piano pins but I do not remember having much success. This goes back to the 70's when some top techs were recommending the rosin for pinning jobs. It might be worth a try though on this instrument. I wonder if it would be worth the effort to contact Hendrik at Hubbard to see what he has to say?
If the problem really IS that the holes are glazed, maybe dressing them with a gun brush of appropriate size will remove the glazing.
The mere act of removing the pins might ream sufficiently and then deglaze as Alan suggests. Usually when you pull a pin, you have to go a size or two larger, at least in pianos.
------------------------------Alan Eder, RPTHerb Alpert School of MusicCalifornia Institute of the ArtsValencia, CA661.904.6483
Thanks Alan, if I can find the right brush it is worth a try.
Indeed worth a try Jon. Unless the pinblock in a harpsichord is shot, one can generally put the same pin back in although it may have to go just a bit deeper.
------------------------------Regards,Jon PageOriginal Message:Sent: 06-15-2016 15:55From: Alan EderSubject: tight & jumpy tuning pins
Though unlikely, if by good luck the wrest plank was drilled all the way through. you could try jacking up a pin from below, then tapping it back down. You could do this without removing the strings.
I have also found that when I made a harpsichord with pins too tight, it was easier to tune with a little gooseneck lever than with a T hammer.
Harpsichord pins don't need much torque. If they get loose, a gummed paper shim works well to give enough torque.
I received some new information from the owner. He mentioned that when he had to replace a string and put the pin back in the block it felt better. I sent all the information to Hendrik. He suggested removing the pins and replacing back into the block. He also mentioned dusting the pin and hole with pure talc as an option. He did not like the idea of reaming unless there are "dire circumstances."
Hendrik mentioned using pure talc on the pins. Where does one obtain pure, unadulterated talc for this purpose? Some searching on the internet and Amazon provided these as possibilities:
Silver Cup Premium Talc Powder, 13 Ounce Shaker Bottle
Typhoon French Chalk Scuba Divers Drysuit Seal Powder
Talc Powder C98 Gray 1 LB Bag Capital Ceramics
I'm guessing the Talc powder C98 but any other suggestions appreciated.