Advice, please.

One or two heads in the treble sound dull, especially at p/pp, but they are not loose or ready for replacement.

Is this likely to be a sign of faults in the hide glue joints between head and shank?

How would you repair them?

If the joints are loose, I take the heads off and reglue them. However, the symptom is that the notes click.

My guess is if the notes only sound "dull", you have misdiagnosed your problem. To me, this suggests a voicing or regulation issue. If the joint was faulty (loose), you'd hear a clicking sound. In that case, you'd want to make sure that the hammer is straight on the shank, and then apply thin CA glue to the end of the shank/tail and let the glue soak in; you do not need to remove the hammer.

CA glue is not good for gluing shanks.

There was a similar problem with another hammer on the piano some time ago.

I steamed the joint to soften the glue and rotated the hammer to reform it, the joint, but the steam had also twisted the shank. After a second steaming, to deal with the twist, the head became loose and was re-glued.

Is there a better way?

PS This note did not click and neither do the ones in my original question, but I can see why loose hammers would click as a general rule.

I definately second this. It will not fill gaps, nor will it stick well to the surfaces that have residual glue. Use a carpenters aliphatic glue (white or yellow) or better yet, hot hide glue. Clean off the previous glue collar first.

I'm going to put in my vote for CA glue on the joint or head. I've found it very easy, quick and effective. In fact I just used it to tighten the joints on a pedal lyre on a grand piano. No more squeak.

Yes. Quite so, but it's also about convenient disassembly, particularly joints that may have to be disassembled easily for part replacement such as hammers.

Thank you all for the advice.

Looking at the Upright Hammer Removal thread again, I see Johnkie recommends heated mole grips and Dan Silverwood went one better with Kamin's curling tongs.

If my daughters do not have something suitable, an alternative to heated pliers might be to put the hammer in a plastic bag and dunk the joint in hot water at 130F to 140F.

Let's see.

Well, I disagree. This was standard procedure at the university I worked for, and studied at. When you get to play any given piano eight hours a day for multiple years, after having done a repair, you have a pretty good idea of how well it holds up.

I too am skeptical that the note is dull because of a loose hammer head. That being said, if it is so loose that the hammer is changing its position on the string and hitting outside the string imprints, it it could make the tone dull.

I too have experimented with CA glue to reinforces loose hammer/shank joints. On one Wurlizter studio at a local school, I put the action in a cradle, turned the action upside down and soaked thin CA into the joint. I followed that with some catalyst spray and it eliminated all the clicking. I must admit that I haven't seen that piano for a few years so I'm not sure how well it is holding up.

I have not had any trouble removing a hammer shank that has been glued with CA glue - its sheer strength is much less then its tensile strength.

That being said, I usually carry a hammer shank removal tool and some Tightbond molding and trim glue for repairing loose heads.

I've never really had too much of a problem with re-gluing loose hammer heads. I find that whilst holding both the front and back of the hammer head and gently rocking it up and down generally is all that I need to remove it from the shank ... and then I'm able to apply a new collar of glue and re-fit. It does tend to be a great deal easier to do on uprights though because one can use a screwdriver under the back of the hammer as a lever and merely rock the front end.

Certainly it could be one source of dull sound, just as a loose centerpin could.



Yes, I have also done this on actions with loose hammer head joints.
I don't think it will have any negative effect on pulling the hammer head if it should eventually need to be pulled.

Gentlemen

The piano was professionally tuned on Friday and I noticed D7 was half dead after that.

Your skepticism made me look again and, lo and behold, brushing the strings at the capo bar with "Kamin's feather" transformed the note from the dullest to the brightest.

Truly amazing!

Thank you.

I don't understand what "Kamin's feather" is. Could you elaborate?

Kamins feather" by now an obscure reference to a conversation on this forum that Kamin (tech in Paris) and I had 3-4 years ago about what affects piano tone and he mentioned that even stroking the string swith a feather will bring up the tone. Nice to know this stuff isn't forgotten, Ian. By the way, how long did the effect of the feather last?

I miss Kamin's posts 'round here. lots of good insights. Are you still out there, Kamin?

Well, if the feather should ever lose it's effectiveness, you could always try plucking strings with a guitar pick pick to tune 'em (sorry, couldn't resist)

Ian:

Sorry to be the eternal sceptic, but enquiring minds want to know, so I have to ask. Steel strings running across a cast iron capo bar, and a feather stroke transforms the dullest note into the brightest??? No disrespect intended, but is that supposed to be a joke? I find the notion outlandish, to say the least, but working in material science and chemistry, perhaps I'm just too narrow-minded about steel and iron... (oh, and feathers too). If you are being serious, pray tell.

rxd:

Yes, Isaac is still out there, I see him posting occasional comments on youtube videos. (Username Pianotec, if memory serves.)

I'm going to be optimistic and guess that it was a joke.

What kind of feather??? I am only asking out of detached curiosity, please don't think this is a DIY question. I mean, I would never think of doing this without the proper training from a recognized expert!

Now seriously, I do believe that stroking a feather on a string can make someone perceive a difference in tone. How many of us are ready to admit that they have touched up a string a bit, heard the tuning improve, and then find out that the hammer was on a different string? The old saying is, "It depends on how you hold your tongue."

In Ian's case, I think he is looking for magic because of other posts that he has made. And, lo and behold, he has found what he sought. Hey, my car's engine always runs smoother and with more power after I wash the body! It's just how people are. If we weren't made like that, there would be no pianos because music would be meaningless.

It possibly that the tone gets even louder if the feather was brushed on either the Yin, or the Yang side of the piano string?

Yes, rxd, I was referring to one of your posts mentioning the feather, but I can't find Kamin's post about it now to see exactly what he said.

I was speaking figuratively of course. My feather was actually the tip of a (retracted) biro which I ran up and down the sides of the strings at the capo bar. One can apply a bit more pressure with a piece of plastic than a feather and I moved the strings just a little from side to side. So no magic except the result, Jeff, just a way to get rid of any corrosion, debris or a tendency to stick in some groove on the capo bar that might prevent the string from vibrating freely.

In answer to Mark's point, the note had produced only a dull thud when played p/mp, no ping at all. I too am surprised such small tweaks (albeit more than I may have led you all to believe) on three steel strings under tension on a cast iron bar can make such a difference, but they did.

I suppose there must have been some small change after the tuning to deaden the note, probably because I had been less than assiduous seating the top octave in the past. Flushed with success I tried gently massaging a few other strings and I'd swear some of that had an effect too, Jeff, but ...

Fortunately D7 was still fine this morning.

Ian's interpretation of the "Feather Technique" seems rather broad! Brushing the string with a feather is one thing, moving the string back and forth over the V-mound is another! Pushing the strings back and fourth out of their seat is a tried and true technique for improving the sound. The "Feather Technique" must be a piano placebo.

Another thing comes to mind: Sometimes a note can be tuned to sound dead. I had a teacher point a note out to me right after I had tuned it. Sure enough, the note seemed to lack sustain. I *slightly* detuned the unison and suddenly the note had much more presence, and she was happier.

Certainly moving the strings is going to knock them somewhat out of tune. The combination of effects is probably why the note is now standing out so strongly.

I was very surprised by the effect that rubbing very lightly downward near the treble section bridge pins of a Bosendorfer had. I used a hammer shank.

Seating the strings will change the tone, as will many things on a piano.

I hesitated to resurect this thread, but Ian took some flack on this one from people who should know better. How can anyone claim to have an enquiring mind and not perform the obvious experiment, with reproducible results, for themselves???. Particularly when claiming to have a scientific background.

The statement in question came from a conversation some years ago on this forum when I had noticed that the power of a note came up as a result of the action of my felt wedges brushing the strings when inserting them lightly to check which string needed the attention. Several other of our more experienced tuners had noticed as well and, among them was the statement that even a brush with a feather will have it's effect, as Ian, quite rightly, found out.

We all know that the changes in a pianos tone when it has been tuned is not purely the result of being more in tune? right? There's something more. I ask because, having just read this thread, I'm not sure how much anybody knows any more.

None of this was claimed to be any form of permanent cure for anything, just observations that any tuner of average intelligence couldn't help noticing in the normal course of tuning, or so I thought.

On that same tack, how can a tuner leave a note not sustaining properly?, How can they tune it properly in the first place without noticing the lack of sustain from the initial attack? It's a vital part of tuning, is it not? This is not advanced stuff.
A note that doesn't sustain is usually dealt with quickly by standard tone regulation techniques, all things being equal, I don't think I would disturb a perfectly good hard won unison. I find it quicker to have a long needle by me during tuning because it is quicker to cure it properly than fight to tune an unison that won't sustain.

Some of the other smart-donkey comments came straight out of the textbook on dysfunctional families. (I was once chided by an elderly dowager for saying 'smart-ass' so I told her the ass part refered to the dumbness of a donkey and somebody else jumped right on and asked her, 'why, what did you think it meant?'.

Anyway, I, for one would really appreciate it if guesswork answers were preceded with the statement, 'I guess....'

Than again, perhaps I'm just getting too damn crotchety..

Rant over.

rxd, I didn't rub hard enough or close enough to the bridge pins to re-seat the strings.

Sorry, Dave B, I misinterpreted your post. What interests me is, how long did the effect last? It's an interesting phenomenon, isn't it? Perhaps it lasts long enough to do some voicing practice without making any permanent changes, as Ian found.

I have hitherto regarded this as merely an interesting phenomenon but your post raises several questions, for example, a piano that hasn't been tuned for a day undergoing extreme nitpicking tuning. Many notes will not be as strong as those that have just been tuned. I have usually just reset one string of an already perfectly good unison to bring it up tonally. Perhaps just inserting the felt wedge between the strings string will do it. Then again, doing a lot of daily tunings on the same piano leaves me with too much time on my hands.

I have no doubt that playing a piano changes it but it can't be proven because we can't know how it would sound before playing it. Having said that, Now I know I've got too much time on my hands.

There was a twist in the tail of this story. As it relates to the vibration of strings, not hammers, I hope you will forgive me for putting it in a new thread.

Before putting Kamin's feather down, it did seem I had to do remarkably little to bring the dead note back to life. Moving the strings was to make sure of the result; I can't say now whether it was really necessary.

Well, the above is clearly directed at me, so I'd better respond.

Before you speak of "flack", dear rxd, please go back and read exactly what Ian found out!

He posted the notion here that running a feather along a string can make a tonal change. When pushed for clarification, it actually transpired that not only was his "feather" the plastic tip of a ballpoint pen, but that he actually applied sufficient force to move the strings sideways, i.e. to re-seat them! If that's the type of misleading writing we're to have around here, and if a concert technician is actually going to come to its defense, I'm not going to spend any more time on confirming any of it with scientific experiments.

My scientific background tells me this:
1) A feather can apply a force/mass in the order of micrograms, or a few milligrams at best.
2) A ballpoint pen can exert up to kilograms, and what's more, it's hard and concentrates the force on one point.
3) To unseat a string on a termination bar, requires significant force.

If voicing with a feather is indeed an



then I apologise to Ian and all other feather proponents for my "flack", and withdraw from this debate, my intelligence obviously being below average.



Ditto.

Sorry. Mark.
Thanks for going to the trouble of responding. I was reflecting the general tone of all the answers.
I was merely answering a request to clarify what seems to be now known as the feather "techique". I quoted what somebody else had said many years ago here and it prompted a torrent of scoffing.

Anyway, back to my main point, did you perform any experiments??

I know one should stop digging when one is in a hole, and that pouring oil on troubled waters often has the reverse effect, but it's all good fun so here goes.

My original post was written (late one evening) after I had discussed hammer heads with the tuner. He said glue joints failed quite often. There had been one on the piano when I got it. It did not click but the dull note transferred when I moved the hammer. Eventually it became loose and I realised what had been going on. I naturally presumed the tuner would, without really thinking about it, that the tuner would not have left a dead note behind and guessed that the joint might be faulty as before. If that was the case, perhaps some other heads might be on the blink as well. So I asked if the symptoms indicated a faulty joint; a perfectly reasonable question, I'd say.

The answers came back that it was probably not the joint, Ryan's post being the clincher. So I went over to the piano (again late one evening) and was amazed that the note showed signs of life as soon as I touched its strings with (as I now recall) a pencil. So that really was my "Kamin's feather" moment. Continuing with my "witness statement", I then went to fetch a biro because I did not want the break the lead in the pencil!

All this took about five minutes and afterwards, to own up to the mistake implicit in the title of this thread, I wrote my notorious post about "Kamin's feather" over a cup of cocoa. The quotes were meant to indicate the cure was ever so easy once the problem was diagnosed. I tried to explain that in the post just above; I found the cure before applying the significant force.

I have seen enough of Kamin's posts to know that he is a very sensitive piano technician indeed, e.g. his descriptions of the finer points of tuning unisons. He might well notice the effects of a real feather that others, including me, might miss.

The moral of this story seems to be to fix the string before the hammer. I at least have a lot to learn about "seating the strings" and precisely how that affects their vibrations and the tone of the piano. I suspect there is a lot more to it than I have yet seen or read.

Not sure whether this is a rant or not.

PS Wrote this before I saw rxd's latest post. I did perform some experiments with, to me, some very surprising results. I put them in a new thread about pressure bars because they have nothing directly to do with hammers. They may be specific to my piano and its age, not very well stated and of no general interest, but I have tried to hint at what the scientific explanation might be for such a small tweak (with a screwdriver wrapped in cloth) having a dramatic effect on the sound of the notes.

My hammer weighs so much that I do not want to increase the weight of my kit, even by so much as a feather.

As an experiment in magic, Jeff, take a feather along one day and wave it at the hissing snakes in those nameless pianos.

I'll tell you what I have done. I have taken a piece of felt and dampered the front duplex while I am tuning. I can still hear the snakes with the felt removed during a performance. I know exactly which notes are being played above the upper treble break.

No, rXd, I must admit that I haven't done experiments with any super-light objects such as feathers, for a number of reasons:

1) To be scientifically valid, especially in a potentially controversial case such as this, they would have to be double blind. I don't have the means to do this. (To wit: volunteers with sufficiently fine ears, measuring equipment, etc. etc.)
2) And if I tried to bring volunteers together for a double-blind experiment on feathers in pianos, frankly, I'm pretty sure they would laugh at me.
3) I might easily fall into the trap of observer's bias, placebo effect, etc., depending on whether I want the feather to make a difference or not.
(Really the same point as no. 1)
4) I carry with me an accumulated body of scientific and technical experience. While this is still rather limited in terms of pianos, it is not in terms of physical and chemical interactions of materials. This body tells me that, in all probability, a feather will do nothing more to a piece of wire other than perhaps remove one or two specks of dust, which would not suffice to change any of its vibrational modes measurably.

On the other hand, if anyone HAS done such a double blind experiment, and has hard data to show that feathers make a tonal difference, and can conclusively exclude observer bias, I'd love to see those results. Any self-respecting scientist appreciates to be proved wrong (provided it's solid proof!), because this serves to further the body of knowledge.

Mark. R. Yes, I agree. I did something similar on an introductory talk on piano technology that I gave to some first year conservatory piano students. The piano was due for service and I asked what would happen tonally if I tightened the action screws as we normally do.

A piano professor with a smattering of piano technology ventured that nothing wwould happen, tonally.

I had a student run scales and select a note that wasn't as lively as the rest. I took the action out and tightened the hammerflange screw and put the action back. That selected note was louder compared to the rest of the piano and fuller than the rest both to the assembled listeners and the player. The professor had the good grace to acknowledge the surprising difference.
I had the student select another note. This time I tightened the wippen screw and even I was surprised at the extent of the change.

I have since done the same thing at all the ensuing talks with similar results.

Is this the sort of thing you mean?, if so, next time I will try the same thing feather if I can find one. I know that a felt wedge will work. I will report back.

Except, how do you know I didn't use mass hypnosis?

Anyway, Thanks for your interest. Fascinating stuff this piano thing.

Well, if mass hypnosis works as a voicing technique, why not?

Jest aside, let's keep it much simpler. Just tell me this, if you may:

How do we know the student struck those notes with exactly the same force before and after you tightened the screws? How do we know the audience wasn't sensitised to this specific note?

By no means do I wish to belittle your talks to first year students, but can you really say with confidence that
... the rest of the piano,
... the player (how he/she played, even subconsciously!) and
... the listeners
were identical before and after you tightened those screws?

A blind experiment would, at the very least, have to keep your repairs a secret from the audience, for example:

Take them to a practice piano that you've tuned but have otherwise left untouched. The audience selects 10 bad notes. You in turn select 5 of them randomly, write the note names/numbers on a piece of paper, give it to an adjudicator, then you tighten the screws on those 5 notes, but leave the other 5 as they were. The adjudicator confirms that you only tightened flange screws. You show or tell neither the pianist nor the audience which ones you've tightened. Each audience member gets to write 5 note numbers on a piece of paper, and another adjudicator does a count for each note. He writes the five numbers with the most votes on a paper. If the two adjudicators' pieces of paper have the same 5 notes written on them, that would be a clear result!

With screw-tightening, I could still see a remote chance for this actually happening. But with a feather? Sorry, no.

(But as I said: I'd gladly be proved wrong...)

As much as I hate to prolong this thread, I would like to share this anecdote as it is pertinent.

This experience juxtaposes (or perhaps explains?) the above experiment. It was a very similar experiment, I was attending a PTG seminar on voicing. The room was full of experts (piano technicians, not first year students), the instructor was a nationally recognized presenter. He ran some scales and selected a note which did not fit in, tonally. He pulled the action, needled the hammer, replaced the action and played the note again. "Can you hear the difference, is it better?" he asked? The consensus was "Yes".

"Well", he said, " I didn't needle the hammer at all - there are no needles in my tool".

It was more of a psychological than physical experiment. Is it replicable? Any day of the week.

Perhaps it is time to fold this one but the last two posts make a pair.

Mark, am I to understand that you would rather have an imaginative guess based on your preconceptions what the results would be because it would be too much trouble to perform the blind tests you describe? I don't think I'm reducing it to the absurd, That's how it reads, purely and simply.

Could this careful teaching not to trust our perceptions be the root of the herd instinct that was a part of Jorgens' scenario? I witnessed this herd behaviour at my first guild convention as a delegate, Back in the 70's. The politics in those days led to my resignation.

Sooner or later we have to trust our own perceptions. Certainly when tone regilating a piano, for example.

I agree, but I don't wish to appear offish by leaving your question unanswered.



I'd word the highlighted part differently (educated guess based on experience in material science), but for the purposes of folding this one: in essence, yes, that's what I meant.