Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Dissecting the Tone of Piano Hammers

I think hammers on vintage pianos were softer than on modern pisnos when the pianos were new. The hammers almost surely were made by hand 100 years ago. I assume that is still true on high end pianos today.

I do not know what you might mean by "made by hand." The great revolution in hammer manufacture came from Alfred Dolge, who wrote about it. You can probably find his books on Gutenberg, definitely from Dover, and if you are interested, you should read them.

I am using a very small gauge hypo oiler for application, or also a recycled CA bottle (cleaned out first with acetone, and with a very fine tip extender) rather than spray. I do have a pump sprayer but find it a bit messy (but I will use it if lots is needed fast).

For the sustain issue I am applying it in kind of a tight zigzag pattern on the lower shoulders, just enough to penetrate about 1 or 2 mm. If, after listening and drying I think more is needed on selected hammers I will apply more at about 3:00 and 9:00. Not enough to penetrate to the core.

From what I am seeing and hearing, this process affects the overall outer layer(s) of felt making them more flexible and bouncy without killing the volume. Best done on a well shaped hammer.

If I need to do serious softening of tone I will spray it healthily right on the strike point.

Peter Grey Piano Doctor

So I tracked down another cause of a hammer sound i was complaining about. I had an f#5 that sounded "felty" and out of place in the scale. Which is odd because I was working on the entire octave all in the same manner. I played the note softly to hear the pp section and yes its too soft. I also listened to the ff and it was also a little soft. So I start adding B-72 to the strike lines and ff, waited to hear if it would brighten up a little.

Nothing.

I figured, I used too weak a solution, and i added more to the strike lines and ff. Gained a little ff this time, but still felty.

I ended up adding 4:8 all the way from 9:00-3:00 up to the peak. Checked it an hour later and the tone was thinner(closed), ff good but still hard to get on a hard blow, overall still "felty". You would think that adding this much B-72 from the peak down it would brighten up pp, but nope.

So, after adding so much hardener and not hearing an improvement, i was beginning to think that the sustain area was too soft.

I decided to pull the action out and began feeling the hammers for differences in density. When i came to the f#5 it felt different. I decided to sand a layer off,instead of adding hardener to the sustain area, put it back in and the felty sound was gone. I had to actually open it up a little. But now its sounded like its neighboring notes.

So when you have a situation like i describe (too soft and no dynamics and hardener doesn't have an affect), here is the cause. Its the tension of the outer layer of the felt. I find this quite common with Ronsens in the sets i have received. Always one or two notes with the felty sound you can't get rid of.

Mystery solved. Next, i'm working on the "slappy" sound. I think this is caused when the layers just below pp are harder than ff. But still working on it.

-chris

If the string grooves are not that deep, how do you guys puff them out a little.

Did a first run, end to end, I hit the very tip 1 pass, hit the meaty shoulder part 2 passes. Finally can roll out some pp.

As for the sustain changes, I'm not sure it's done much. I watched the soak pattern very carefully, it's going in at most 3mm and only the very rim, I don't think it's penetrating deeply.

The bulk of the sound transformation likely occurs at the tip. This might just be my particular hammers though, because the inner layers are extremely hard.

The B2 is still dissolving I will spray some when that finishes.

Overall, it works exactly as advertised without pokey pokey.

Amazing isn't it!

Regarding the string grooves. it best to leave them and just remove excess felt.

Do you know the brand of hammer?

-chris

It's just the cheap crap (Todd) that came with my piano stock. kwai

Did you try the 1-1-1 in the low shoulders? If its not penetrating with a sprayer, a hypo can saturate better. Also, i have used a 1-4-1(1 part water, 4 parts alcohol, 1 part water) with good results. Please remember, this is only used when you hear a sustain drop because of the hard shoulder. Listen to each hammer's sustain and see if one stands out that has a quick decay and then find one with a good sustain. Apply the softener solution to the one with a quick decay and use the good sustain hammer as a comparison to see if there was an improvement.

-chris

In the good old days, carding and ironing new hammers was mandatory. Maybe it still is

Update:
So as you guys know I have been playing with the B-72 as a hardener. It characteristic is that it remains flexible. Well this isn't always desirable. The Big Sexy hairspray hardener leaves a crisper film. This came in handy today in bringing 4 notes that sounded open and just a little softer than their neighbors. I did 1 pass at the peaks and another pass on the shoulders with the Big Sexy and perfecto!

So its good to know the characteristics of both hardeners.

-chris

Chris, good to know my bottle of Big Sexy is not wasted. Like your wife, mine will not put it in her hair.

Did you have to wire brush the tips after applying to remove any ping?

Thanks.

Chris I am assuming this was a typo. 1-4-1 (1 part ALL, 4 parts alcohol, 1 part water) correct...yes?

Peter Grey Piano Doctor

Emery,
Glad to our wives are in sync. Most of the time i brush, sometimes it don't want it. But i like using the brush. I have 3 i use. The steel brush (course) and plastic bristle brush(fine) and a toothbrush (extra fine). I don't recommend using a brass brush, for some reason it wants to blacken the felt.

Peter Grey,
No typo. I add more alcohol when i want more penetration into the hammer felt.

I do have an experiment in mind. This is top secret so don't tell anyone. I am going to be trying DMSO on piano hammers. No one is using it in the piano industry. But in the health industry it has amazing qualities like absorbing into substances quickly at the cellular level. If anything can bring old dead hammers back to life, then perhaps DMSO can. If anyone wants to get ahead of me with this experiment, then go for it. I'll let you know what i discover after i try it on old hammers. Cutting edge though, and fun stuff this voicing is.

-chris

Did a quick video with my iphone.
https://www.youtube.com/watch?v=d4U_ZeSEfcc

And a picture after delivery to the happy customers home.




-chris

Very nice Chris. The piano sounds awesome and looks great. Nice playing, Straw hat completes the look!

Hi Guys,

I have just find this interesting thread.
I have an old yamaha GH1 which I always find too bright sounding.
I have needled it to death, and it always sounds better and mellower after needling.

however, the sound always get brighter with use, so I have to repeat the needling every 2 - 3 months.

Is this voicing process using fabric softener suitable for my yamaha hammers?

Welcome tirta,
Yamaha hammers are indeed a hard, bright hot pressed hammer. The real fix is a better hammer of course. Cold pressed hammers have been used on Yamahas with great success.

However in the meantime, Try the 1 part All : 2 Parts Alcohol mixture. I pass on each shoulder (10:00 and 2:00 o'clock), And another pass on the tips. Wait an hour and listen to the results. If the change is dramatic, then this is probably enough and then just maintain it. If there was little change, then I would switch to a hypo-oiler and apply the 1:2 directly on the tops(pp) and soak it. As it penetrates it will form a semi circle which will go into the (open /closed area), let it penetrate down to the moulding (ff). Again wait at least an hour or longer and listen to the results.

Keep us updated.

-chris

Tirta, I don't know how your Yamaha hammers compare to the ones on Kawai GL10. However, I had some overly bright notes in the upper treble that no amount of needling could fix. The 1:2 Fabric softener : alcohol mixture fixed it. I sprayed 4 passes on the shoulders only. I think that is how Todd did it in the video. Chris, however, has honed the process even more.

Good luck!

Chris and Emery, thanks for the reply.

Since I am in Indonesia, I have difficulty finding the same brand that you use.
Is it ok to use another brand?

Can you tell me the real ingredients of ALL fabric softener?
What kind of fabric softener should I look?