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

In the past I have used one of the liquids the old timers used to use - flexible collodion. Collodion is a mixture of nitrocellulose , alcohol, and ether. Whereas nitrocellolose will dry hard, collodion remains flexible. It gives a warmer, creamy, and more rounded tone than our nitrocellulose concoctions. It is extremely flammable and volatile. And it has ether. Not so great to work around, which is why I rarely use it these days.

I have heard of Ethyl Acetate being used in voicing but have never tried it. What kind of sound are you getting?

Regarding downbearing, i know several rebuilders who have hundreds of soundboard installations under their belt who, over time, have moved towards thinner panels and lighter ribbing. They have also reduced the amount of downbearing they use. One thing that is really useful with downbearing are adjustable perimeter bolts. They give you more flexibility when globally setting downbearing for a new board (or an older one). If you do not like the bearing you have set initially, you can raise or lower the plate, or even cant it slightly if need be. You can make your own, but Wessell, Nickel, and Gross sells them for about $9 per bolt. Nickel plated, so they make the plate look like a million bucks.

Regarding clarity in the mid treble up, hammer weight becomes very important here. Most hammer sets would benefit from a diet in this area.

In the past I have used one of the liquids the old timers used to use - flexible collodion. Collodion is a mixture of nitrocellulose , alcohol, and ether. Whereas nitrocellolose will dry hard, collodion remains flexible. It gives a warmer, creamy, and more rounded tone than our nitrocellulose concoctions. It is extremely flammable and volatile. And it has ether. Not so great to work around, which is why I rarely use it these days.

I have heard of Ethyl Acetate being used in voicing but have never tried it. What kind of sound are you getting?

Regarding downbearing, i know several rebuilders who have hundreds of soundboard installations under their belt who, over time, have moved towards thinner panels and lighter ribbing. They have also reduced the amount of downbearing they use. One thing that is really useful with downbearing are adjustable perimeter bolts. They give you more flexibility when globally setting downbearing for a new board (or an older one). If you do not like the bearing you have set initially, you can raise or lower the plate, or even cant it slightly if need be. You can make your own, but Wessell, Nickel, and Gross sells them for about $9 per bolt. Nickel plated, so they make the plate look like a million bucks.

Regarding clarity in the mid treble up, hammer weight becomes very important here. Most hammer sets would benefit from a diet in this area.

Dropper, Riblets and a little Big Sexy!!!

So here is a very interesting voicing problem and how i fixed it. I share this because it required many solutions.

The problem: A very cheaply made circa 1929 4'10 Behning Baby grand piano. And the customer is very attached to it as it was her Grandmothers piano. I just rebuilt the whole thing - new hammers (Able), new soundboard, new pinblock, new action parts. Everything new. Got it to the voicing stage after much regulation. At this point its voice is not good.

Bass:
The bass was very low in volume, and too soft.

Break:
The break had a tremendous amount of energy, more so than the rest of the piano. Mostly because it had a little four note bridge in front of the long bridge.

The rest of the piano sounded very good except the top five notes.

To fix the bass I had to apply B-72 4 times to make it have the same volume as the rest of the piano. But how i applied it is the interesting part. I used an eye dropper. I use to use hypo oilers, but the problem with them is consistency. The eye dropper on the other hand, is very consistent, and you can put the exact same amount every time. I used the 4g to 8oz mixture and applied it directly on top (two droppers each. the dropper only fills half way). The two droppers was needed for the B-72 to soak to the volume section right above the moulding.

To fix the energy problem of the break required the use of riblets. I had to make 3 riblets about a foot long before it controlled the wild beast of the break.

To fix the very top notes required two applications of the 4g-4oz B-72. Once they started to ping, i just used the steel brush to remove the crust.

After one more listen, i determined that the break did not have the same brassy sound that the bass now had. Question: How would you add hardner to the top without raising the volume? I chose to use the Big Sexy Hairspray. Unlike the B-72 that doesn't ping too easily, The big sexy does ping easily. I used that to advantage and it worked like a charm. Once it started to ping, i again used the steel brush to tame it a little.

The treble on this piano hardly needed any voicing work due to lengthening the scale and the use of hickory bridge caps.

It sure will be fun when the customer comes on Friday to hear this little beast.

Cheers!

-Chris

Nice work Chris. Is there a chance we can hear it too?

I'm with WBLynch. I'm also interested in hearing how it sounds. I have a Begining grand as well an would like to hear what another sounds like with improvements.

I have questions about the 2:1 fabric softener solution.

(1) For application, I am thinking of using an airbrush with a small portable compressor. Would an airbrush be overkill? It kind of makes sense to be able to have much finer control of the spread and amount of solution applied to the hammers.

(2) As for the fabric softener, I will use Seventh Generation Free & Clear (https://www.seventhgeneration.com/liquid-fabric-softener-free-clear). No fragrance and no dyes.

(3) I can get both 99.9% denatured alcohol and pure ethanol here in Singapore. There probably isn't any difference between using one or the other but I thought I'd ask anyway.

Quite a number of my clients have older pianos with hard clangy hammers. I thought I'd offer them chem hammer voicing as a quick and low-cost way to improve their pianos. Voicing is otherwise something that is done only for pianos in the main concert venues and the conservatorium.

--Benjamin

Hi Benjamin,

I found that an airbrush is too small to be practical, but feel free to prove me wrong. The bottles that Emery gets from Amazon are good for in home use. In the shop, i use my small sprayer.

The advantage to using the All free and clear that we use is that Todd tried ever known fabric softener on the market. And the All Fabric softener stood out as the best. Todd uses it a lot, and i use it a lot, so its proven safe. Feel free to use the one you picked as "no dye" is a good start. Let us know if the product works well for you or not and hope that there is no bad side effect.

I also use both alcohols.

look forward to hearing from you,
all the best.
-chris

Chris,

Thanks for the quick reply.

Can’t get All here in Singapore. I might as well give the Free & Clear a try. If it doesn’t work I could look for a fabric softener with the same active ingredient in All. All publishes the contents of their products on their web site.

Your point about an airbrush being too small is noted. I might be able to find locally something equivalent to Emery’s sprayers.

Can you give me some guidance about the sprayer you use in your workshop? Say brand and model?

— Benjamin

Chris,

Thank you for the tone diagram. It gives me the means to ask the following question: One of my clients has a year-old Hamburg Steinway Spirio B, that does not sound right. It has a breathy attack and sustain decay that is a mix of the two lower red curves. What might be causing this uncharacteristic voice across the entire keyboard? I can think of two: Inaccurately set strike point, and hammers (which are Abel Purple) that are too hard. Hard to believe that this piano passed factory QC.

I might suggest chem voicing to him for consideration, after I’ve gotten enough experience with it.

— Benjamin

Hi Digitus. I used to have an airbrush like this in college and as I recall, its spray volume was similar to the pump sprayer I used in the video. The airbrush would also give finer control than the pump sprayer. If your airbrush is siphon feed and has a container underneath, it should work. The smaller gravity-feed airbrushes with the small cups on top that are designed for fine work might be too small, however. They would probably still work, but would take longer and have to be refilled a lot.

Thanks Emery! Much appreciated. 👍