Hello all.....told you I'd be picking your brains before long!!
I have a problem with a piano Im working on at the minute. It is a 90 year old over-damper(yuch!) piano and some of the black keys are sticking. It seems to be because the fronts of the black keys are rubbing against the back egdes of the white keys.

Prob #1 : Why would this happen in the first place? The white keys seem to be in their correct postion (judging by their postion with the key slip). The black keys seem to be in their correct position (judging by the fact the capstans are sitting ok under the wippen heels). And the front rail pins seem to be perfectly vertical with no front-back slant.

Prob #2 : How should I fix it? Is this a reasonably common fault that I just havent come across til now? Or should I just file/sand away the back edges of the white keys?

Thank you guys in anticipation

Best Regards

Mark

P.S. if this turns out to be something really glaringly obvious I think I'll have to bury my head!!

Check to see if the balance pin holes in the keys have become elongated. The keys should not move forwards or backwards. If they have, that needs to be corrected. Some cardstock glued on the worn edge will correct it.

I agree on the "yuck" about overdampers. At face value - the overdamper situation itself should have no bearing on your key issue.

Where I have normally seen this particular issue is after keytops have been replaced. If they have been filed "properly" and then humidity changes cause movement later - what was ok may now be sticking.

If the keytops are original or not recently replaced - you want to make sure that you have really identified the problem before you just start filing. filing away at the contact point should loosen things up - but again - make sure that you are solving the problem and not a symptom. Is the black key moving forward for some reason (loose, messed up pins etc)? Is everything in the action for that key working properly? (in other words - are the things that should give the key the proper return ok?)

If you can't find any other issues - then filing (just a little at a time) would be the proper place to start (especially if it is just hanging on the keytop and not the actual wood of the keystick)

Thank you guys for the speedy response.

BDB - I dont think the holes are out of shape, but its something I will double check when I go back. And......cardstock? Dont recognise that term....what is it?(this is the problem with tech on different sides of the Atlantic talking....I have discovered that we have different names for the same thing )

Jim - I believe these are the original ivories....the piano has been holed up in someone's garage for 12 years and in a bad state of regulation! Though, I did lift the whole action assembly off(coz I thought, too, that might be the problem), and the keys are still sticking by themselves.

Also.....another weird thing that may or may not be part of the problem....and it is another thing I have never seen before. When I turn the front rail pins to the 'straight' position...the keys stick on them. When I turn them approx 45 degrees anti-clockwise, the keys free up!!!!???WEIRD!! You would think it should be the other way round, eh?

Regards

Mark

Cardstock is thick paper. I use a strip cut off a business card.

If it was in a garage for 12 years, too much humidity could of made the keys swell? Ireland is very humid is it not? As for the front rail pins, I've seen some old pianos where the mortise is not parallel to the sides of the keys.

Hello accordeur. Nice to hear from a Canadian. I trained as piano tech in Canada, so it's like a second home to me now!

No, Ireland is not humid at all.....and that is why all this is a little difficult to understand.

The mortise seems to be parallel, though. And if it is not parallel.....it is CERTAINLY not out by 45 degrees.

regards

Mark

Well I'm scratching my head now..... good luck.

The Piano Doctor. Hi from cape cod mass.
Do you have at times a high change in humidity where the piano was stored.I ask because I have seen the same problem here. I have had to steam off the black sharp tops and reglue some that were to drastic for filing.The humidity when to high moves the sharp tops,then when humidity drops they reset themselves forward,sometimes filing does the trick.Are the backs of the sharp tops even at the fallboard.

I know what you mean Jeffrey....I lived in Canada for a year and I know the drastic changes in humidity you speak of....but here in Ireland there are no such drastic humidity fluctuations. But please explain more what you mean about the filing.....it may be something I can use.

Thanks

best Regards

Mark

You can bend the balance rail pins in opposite directions to separate the two. With the front rail pins at 45*, somebody did some work that wasn't right.

If a quick file to the front of the sharps makes everything work, have some black paint with you. Make the flat spot on the front of the sharps all look the same. No one will ever know.

I guess I would file the backs of the offending naturals. As for the front rail pins, I would straighten them, remove the bushing felt from the key mortises, file them (mortises) straight and re-bush.

Thanks Mr Kia. I was thinking it might come to filing the naturals. You are right, I think, about the mortises...it is something that they need - and something which I would like to do - but the family have just acquired the piano in their home, and I think I will have to work to a budget they have. While this work on the mortises will be needed sooner or later, it is a job which would take AT LEAST one whole day to complete, and I think it is not something they will be willing to pay for at this moment.
Their little girl(approx 8-9 years old) has just started piano lessons and I have managed to convince them that piano will need at least 2-3 tunings + a regulation, costing them about £170. I think, unfortunately, at this stage they will not want to pay another £150 to have the mortises filed and re-bushed!

Regards

Mark

Incidentally, Keith.....will bending the BR pins backwards and forwards not make the keys bind on them? Does this not make it more difficult to push the keys down?.....sort of sluggish?

Best Regards

Mark

I would try filing the point at which the rubbing takes place first if time and money are an issue.Do the keys that stick first.Then the others so they don't stick in the future.You can try bending one pin to see if that may help,all options are posible.to do the filing remove the sharp keys one at a time and looking at the key from the side ,you will notice the curve to the front top.Put the key in a vise so that you can file down from the top in the direction of the curve.Remove a litle at a time untill the key works.Then paint the end.


Before doing this check that the backs of the sharps are evenly spaced from the board behind.I call it the fall board.This will indicate the pins are the problem if the spaces are diferent or larger on the sticking keys.
Just a side note: my grandmother on my mothers side of the family came from Doublin,hope I spelled it right,I hope to go there after visiting Norway and the rest of my Clan.Look forward to conversing again soon.

My guess is that the piano is worn out and in need of replacement.... or,

Problem #1- key slip might be warped, and is not a good judge of key height. I tried that once in a Yamaha class, they all made fun of me for trying to take short cuts. Do check height with respect to the key frame. And, check that your sharps aren't dipping too deep?

Problem #2, I would always much rather file the sharps than touch the naturals. Ebony seems cheaper then ivory, is softer, meaning less work, and there are fewer of them anyways.

Jeffrey - I guess you mean 'Dublin'? It is the capital city of the Republic of Ireland.....about 100 miles from Belfast - the capital city of Northern Ireland. Dublin is a beautiful city with plenty to see and do(Grafton Street, Temple Bar, St Stephen's Green etc etc)....don't forget to get a coffee from the Bewley's coffee house on Grafton Street. Thanks for the advice - and the advice of everyone - hope you have a great time there!

Richard......you ARE right...the piano does need replacing, but the family are not a wealthy one and are trying to give their young daughter a start in music. You know the scenario?.....don't want to fork out the considerably large bucks for a new piano until they're sure their daughter will continue on with the lessons. So, Im trying to make the piano as playable as possible for them in the short term with a couple of tunings, a few repairs and a regulation. That alone will already cost this family a substantial percentage of their income.

Thanks....I'll try filing the sharps then. Incidentally, what do you guys colour them with after filing? Just one of the "sharpie" markers?

Regards

Mark

Thanks all guys for responding to this little prob...I love this site.... :3hearts:
Just to let you know...I tried first Keith's idea of bending the BR pins....and it worked to a certain extent...but not enough on all the keys(didnt feel too comfortable bending them TOO far). On the remaining keys that still rubbed, I filed the ivories where they contacted the front of the blacks....only a couple of light passes witht the file was sufficient - worked pretty well.

Im so glad I found this site, coz here in N Ireland pianotechs are quite rare....really glad I have found new friends to call upon in my hour(s) of need!!!!

best Regards to all

Mark

Thanks for the follow-up, Mark.

You are right, the bending of the pin is for small adjustments and mainly to make the front of the keys all look the same. The higher the stack of punchings the more adjustment.

Almost all balance rail pins are bent. The key has to be leveled etc. If you see a piano where the keys look all wacky what has happened is the pins are loose and they rotate in the direction of most pressure. Glue size loose pins or bending them doesn't do any good.