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You'll probably want to replace the spring cords too (after 110 years)


The piano does look very interesting.

Peter Grey Piano Doctor

It sounds a bit scary. Maybe I can make custom new blocks and drill holes for the wire in the right angle. I want to preserve the old wire and the shape of the dampers and glue new damper felt on it.

That is why I hope I can keep this hammers (and strings). I don't want a mellow sound.
I think it wil play better. Right now you don't have much control, especially when you play soft. It feels like the keys are floating in space.

If you use round damper blocks, you will not have to worry about the angle of the wire. You might be able to drill socket holes in the existing heads.

Remove the damper blocks from the wires, glue them back together, glue thin veneer pieces on both sides to reinforce them. clean the holes with a drill and put them back on the wires.
Spray the felt with rubbing alcohol (30% water), then lightly brush the felt with an old toothbrush. Let it dry before pressing them against the strings.

That's interesting about the rubbing alcohol. Can that technique be safely applied (with due care) to dampers in place on the action?

Light moisture, penetrating the surface, will often lift wool parts that have been compressed, such as dampers or hammers.
But wool tends to repel direct application of water, so

One approach is to use steam, carefully. There are several techniques for this, but they do require the right equipment, such as a small steam cleaner, a steam kettle or damp cloth and iron, and can be overdone.
And a simple alternative is "cold steam," i.e. alcohol with water added.
The alcohol penetrates the wool, leading the water in. The alcohol evaporates quickly, leaving the water to work its magic.
Rubbing alcohol, usually 70% isopyropyl and 30% water, is a nice proportion, cheap and easily available.
My choice is almost always a light spray from a cosmetic spritz bottle.
Two concerns: Don't spray onto shellac finishes and don't use it to clean keytops; some plastic keytops may eventually crack, Yamaha specifically.

For pianos I serviced regularly I spritzed the hammers lightly with each tuning. It helped release the string grooves, undoing six months of wear on the strike surfaces before it had begun to pulverize the felt.
I had good results on 100 year old upright dampers using alcohol and a soft toothbrush massage. Perhaps not like new, but ten minutes was affordable and made noticeable improvement.

My neighbors made a bar from an old piano and they gave me the action. I tried the alcohol on that action, I mixed pure alcohol with water 1:1 and sprinkled 5 drops each on three hammers. The felt looks a little bit bigger then the felt on other hammers now, so it works indeed! I also tried 9% hydrogen peroxide for bleaching hair on one hammer of that action, just for fun to see if it would fall apart but it didn't yet and is now white instead of yellow. I also cleaned one key of the Thürmer with it. In the images on the first page you can see that one key is white.

The damper felt on the Thürmer needs to be replaced, it's not hard but very soft and is falling apart.

It sounds a bit scary. Maybe I can make custom new blocks and drill holes for the wire in the right angle. I want to preserve the old wire and the shape of the dampers and glue new damper felt on it.[/quote]

Mama mia…

Haha, I'm sorry, so that's not a smart idea I guess

Thank you for that very helpful and full reply, Ed. I've had success with steam voicing of rock-hard hammers, so I know the effectiveness of steam carefully applied. I do have a bottle of 70% isopropyl, so i will give this a try on dampers at some point.

10 of them have cracks, all in the middle section.
So or I replace all of them with the round blocks or I fix the middle section only. I thought, I saw blocks with the same dimensions, stick a straight wire in the hole of the old blocks, measure the angle and drill a hole with a drill press in the same angle. The part where the damper felt is attached to is good. Doesn't sound that hard but maybe I'm wrong.

An image of a good one, I want to replace the part where I drawed a circle, and only the broken ones. I want to replace the felt on all of them.

Before you fire up your drill press, just try repairing with some thin CA glue first.
That will be WAY easier than fabricating your own damper blocks.

If pieces, like damper blocks, have broken, I will replace all of them. Odds are, others will break later.

There is stress on those blocks because the screw pushes between the wire and the wood. Later damper blocks have metal inserts which take up the stress.

There really is no reason to try to keep the old dampers. I would just replace them. After all, nobody is likely to look at them, except technicians.

Okay thank you all for explaining!

I will repair them first. I also have hide glue, I think I will use that because thats easier to remove afterwards. When other blocks are going to break I will replace all of them at once.

Josephine-
I like your careful approach. To really understand a piano like this, it is best to retain the original parts as much as possible as the first stage of restoration, because this will tell you how the piano originally worked.
When you understand the original intention, you can make informed decisions about replacing parts or changing parts for more common contemporary parts.
The damping style of a piano is part of its original design and sound quality.
Your choice oƒ hide glue to repair the split damper blocks is good, and I do believe you will need to reinforce with little slips of veneer. Or cardboard, if you know how to feel the grain of cardboard and run the grain across the splits. Cardboard is stiffer in one direction, and that is the grain direction.
The treble damper felt you showed in the photos may be capable of being saved. Dampen the felt, press and massage a little, then let it dry, pressed lightly against a flat surface.
You may (perhaps likely) eventually replace the dampers, but, if I understand your interest correctly, this will enable you to play the piano with its original parts as you decide your long term intentions. I am assuming this is a work of love andthat you will enjoy getting to know this piano as much as possible.
I am very curious what you may learn at the Thuermer Museum, and what advice they may give you.

Josephine83,

You can make these broken damper heads stronger than they were when new. After carefully gluing them back together securely, drill through from front to back THROUGH the repaired area. Then glue in a small dowel (round toothpick is sufficient). Two would be even better than one (above and below the screw). Obviously you must avoid the area where the wire goes or it will defeat the purpose. The blocks will NEVER come apart again. In fact if you do this to the ones that are not broken yet you will save yourself grief down the road.

Edit: I do not take credit for this technique. I learned it from someone else. It can also be used crosswise on a broken flange (when no suitable replacement is available). Solid as a rock.

Peter Grey Piano Doctor

Nice!

Thank you so much Ed and Peter, very good ideas!!

Ed, the dampers don't work as they should, especially the middle section doesn't stop the sound anymore. The felt is so loose, you can see the layers and bend it in every direction. Also some pieces of felt are torn. I don't want to replace the heads. I found a shop that sells strips of damper felt without the red under felt. I can cut them in the exact right size. I downloaded an image of those damper felt strips to show what I mean:

That's the stuff!
You'll need a very, very sharp knife to cut it without distorting it. A shop technician would have a special support block for cutting damper felt, but you can do without it.
You can scrape away the old felt, or you may use water and alcohol to soften the old glue.

After many years I finally tried a surgical scalpel. You can get a handle and a pack of 100 disposable blades.
It has made everything I do with blades easier and neater.
Just be careful with pressure, the blade can snap.