buy a new action or re-felt

I take the liberty of saying that 8000 euros seems like an exaggerated figure to me. However, one must carefully evaluate what type of hammer group to choose. The choice, in addition to affecting the sound, greatly affects the keyboard balance which, in any case, must be redone. I have observed, for example, that mahogany or walnut hammers of a certain weight can favor less key weight and, consequently, with the same key descent weight, greater dynamics. Greater dynamics means greater ease of keyboard playing. This does not sacrifice the dynamism of the sound and the various levels of sound power.

Naturally, in my opinion, it goes against all common sense to shave down existing hammers because, as mentioned in numerous posts, one ends up distorting the geometry of the action and the sound becomes harder and woodier, as the hammer has lost the areas where it reacts positively and diversely upon impact with the string. At first, it seems that the hammers sound good, but in a short time, especially in the highs—which are often erroneously too rounded—they make the sound "flat" and almost devoid of sonic dynamics. Last but not least, it decreases the key descent weight... but, even more seriously, it decreases the return weight of the keys themselves, altering and making some technical dynamics difficult (repeated notes, octaves, etc...)

In Europe, the Renner company is highly respectable and historic, but other manufacturers build exceptional hammers. It is up to the technician to decide, but not blindly (just a hammer group for Schimmel and that's it!), which type of hammers to install. The shanks must be of excellent quality with felt heads mounted in genuine leather. Every shank must be checked before being installed regardless. The inefficiency of some pins may exist due to their storage; in this case, the pin must be changed so as not to cause false discontinuity in the final weighing of the keyboard. Also, all the action pins must be checked (fork pins, lever pins, and escapement upright fork pins) and every part that generates friction must be checked. Everything must be within the values and tolerances dictated by the Manufacturer before proceeding to the final weighing. Once the hammer group is installed, which must be pre-voiced, one will proceed to the regulation, rebalancing, tuning, and final voicing!

This procedure must be carefully evaluated in the presence of the instrument. Anything approximate is not enough. One must see how it presents itself, specifically the state of friction and the state of other mechanical parts (for example, the cashmere cloth of the keyboard, which is of fundamental importance for smoothness).

I am not very in favor of re-felting when it is possible to replace the hammer group. Furthermore, in re-felting, the old felt heads and the old center pins of the forks are preserved.

One last thing I always strongly recommend: ask to have the old hammer group mounted on the old shanks returned to you and keep it: IT IS IMPORTANT!!!!!!

Regards and good work

Paolo

Hello everyone.

I am joining this post to ask for advice.

I have a German upright piano from over 100 years ago. It still sounds decently, but the hammer felt is very worn out and especially in the highest notes, where they are almost at the wood, a rather loud "tac" can be heard with every strike.

Sooner or later I will decide to replace the hammer felt.

The question is, what hammers should I use?

On a website, I found Abel hammers of all sizes. In my piano, the hammers are made of light wood (hornbeam?) without underfelt and are of different sizes. The low notes have hammers approximately 58mm long, while the middle and high notes have hammers of approximately 65mm.

The closest sizes in new hammer sets are 60mm for low notes and 68mm for the others.

The drilling measurements are also listed, but they seem standard to me.

I would like a soft sound; does underfelt help or is it better without?

Thanks to anyone who wishes to respond.

Good morning and Merry Christmas.

When replacing the hammer rail, many things must be evaluated. First of all, one must understand if it has been planed and determine the actual length of the hammers. Identical thickness for the bass and treble, and correct drilling. The underfelt is merely a visual detail (as told to me by Abel himself). What is important is the compression and the type of felt. The technician evaluating the work should have the competence to obtain this data. Then, one must reproduce the same drilling, both in terms of distance from the apex (referencing the original) and inclination, as well as the angle relative to the rail (generally 91°). A good hammer rail must lend itself well to voicing, which the technician must know how to do, developing the maximum timbral quality within the hammers.

However, if the hammer rail is reduced "to the bare minimum," as you say, then one must also verify the efficiency of all the mechanical pins and eventually replace them, increasing their size (hammer butt pins, escapement upright pins, jack rail pins). A check should also be performed on the heel felts that come into contact with the keyboard pilots, or on the felted buttons if the pilots are designed that way.

Attention should also be given to the front and center keyboard bushings and the related pins. If the cashmere is old and/or the pins are oxidized, the keyboard slides poorly and the keys might even stick during descent under non-perpendicular stress of the keys themselves, generating an apparent stiffness.

Surely you will have the competence to evaluate and carry out all these phases which, together, restore good efficiency to the instrument. Such interventions are interdependent, as I have said many times, and therefore omitting one could compromise the full success of the others. Otherwise, a competent technician will know how to advise and help you.

Good luck with your work

Good evening, can you indicate where I can purchase the new hammer felts to be glued on? Thank you.

I advise you against replacing the hammer rail yourself. You could void certain references that must be preserved, and it is a highly skilled job. It's not enough to just glue them; there are many processes that require special tools and machines. Specific skills are also needed, even in balancing the keyboard. Hammer rails vary in compression, weight, shape, etc. You must choose the hammers most suitable for your piano.