29. Piano Hammers- Voicing and Buffing

We sell unique tools for voicing hammers in all pianos.
These tools exist nowhere else in other trade catalogs.
Satisfied customers from Omaha to Thailand. 

Let's define "voicing"

Voicing is the art of making the hammers produce the right sound. The most common reason to "voice" hammers is because of wear, so we start there.

Voicing worn hammers-

A worn hammer will look like the one in the diagram. It will be flat on the front, and it will have deep grooves as you look down on it from above, as in the diagram.

For this job all you will need is a package of generic emery boards, AND you need plenty of time to do your best work. The objective is to take off only enough of the front of the hammer so that it is flat and round when it hits the wire. Note the dotted line in the diagram.

UPRIGHT PIANO:

Hook the index finger of your non-dominant hand under the hammer to support it. If you don't you WILL break a hammer off. Hold it about half way between rest and the wire. With the other hand, begin to file the front round part of the hammer. Use steady, level and medium pressure strokes. Begin at the fat part of the hammer (from the top and from underneath) and stroke toward the front of the hammer. DO NOT FILE THE FRONT OF THE HAMMER. You will end up with a rough felt tit on the very front of the hammer. Take this off gently as your last step.

GRAND PIANO:

Everything is the same, but you must remove the action from the piano as instructed in Chapter Five. Stand at the back side of the action, and work on the hammers as you cradle them in your hand. Do not file them as they lay on the hammer rail. You need to steady the hammer so you don't file unevenly.

DO NOT: file from side to side.

DO NOT: File the smallest hammer in the top treble. They may even be down to wood. Carefully shave off the top a bit with a razor knife to help them hit the strings instead of the bearing bar.

DO NOT: Try to cut felt away with a razor knife to speed up the process (exception the last top treble notes as above).

DO NOT:  Use a Dremel type high speed tool to do this job, even if your tuner says he does.  It is too easy to slip and destroy a hammer.

Here is the Most Important DO NOT:

Only file in to the bottom of the grooves made by the wire. DO NOT take off new felt beyond the bottom of the grooves.

You must take off enough so that you have a round smooth hammer in front, but NOT a point, and not flat. If you have questions, go find a new piano, and look at the hammers. This will show you what you want.

This is really a very easy job, but you may find that tuners refuse to do it. The reason is, if something goes wrong, some litigation junkies will try to get a new set of hammers out of the tuner. So, if your tuner would not do them, do not let that terrify you.

If you want to speed up the process, I will let you go to the drug store and get a Dr. Scholl's callous grinder. It has a plastic handle and a course and fine side made of metal. Use this to file the hammers quickly, but before you get to the finished product, use the emery board. If you try to do the whole job with the Dr. Scholl's file, it will leave grooves, which is not desirable.

Support the hammer well when you do this so that you don't break it. If the hammer is now too quiet, douse it with half and half denatured alcohol and varnish several times until the leather hardens

If the bass hammers are not deeply grooved, leave them alone. The ones which need the most help will usually be in the middle of the keyboard where it is played the most.

There, you did it, and that was a $200 job in most cities.

 

Worn Down Hammers in the Top Treble

You may want to leave the last five hammers alone in the treble. If they are down to wood, or the felt is pushed up and keeping a treble hammer from making a good sound, here is a repair.  Trim the felt on the hammer, top and bottom, quite thin.  Cut a strip of thin leather about an inch long, and baptize it in Elmer's glue. When the glue is almost set up, glue it to the hammer as tight as possible with a wooden clothes pin for a clamp.  Leave to dry for two days.

Voicing Hardened Hammers

Contrary to common sense, piano hammers harden with age. You would think they would soften and turn to pillows. Not so. If your hammers are loud, too bright, or just plain harsh-- they sound like twang instead of music, it is because they have hardened. This should only happen on very old pianos. It may also happen if water or Uncle Harry's coke spills into the hammer area as he does his forte rendition of Chop Sticks for you.

It could be that you have an Everett, or one of several brands which are very bright, and it bothers you. You may have an Everett in a small church or school room setting, and it is overpowering the singing. DO NOT put a thick pad of material on the back. That will muffle the sound making it sound like you are playing under the bed or in a closet. Do as follows:

Buy our voicing tool for best results.

If you do not want to buy the voicing tool, you will need a heavy needle or a dentist's probe with the long needle-like end. If you use a biggish needle (which you stole from your wife's sewing kit), break it in half, and mount the broken end (with the point) butt end into a one and a half inch piece of three quarters inch dowel, as in the diagram. Grab the piece of needle tightly in a pair of needle nosed pliers, and tap the pliers with a hammer to back the needle piece into the wood.

You may also find a dental probe or pick is a great "picker." But, the voicing tool we sell will be safer and give better control.

Now, starting at the break, or change over from bass to the treble (where the wires change from angling to the upper left to the middle wires), grab the first hammer with your non-dominant hand. With the voicing tool, or your homemade tool in the other hand, push the point through the hammer SIDE as shown in the diagram until you go about two thirds of the way through the hammer. The trick will be to remain steady as you do this so as not to break a hammer head off. Change hands, or positions, and do the same from the other side of the hammer.

I like to use only two needles in the voicing tool so I go slower. This keeps me from rushing too much and over softening.

Never push the tool point through the front of the hammer. Some technicians run the needle in right behind the front of the hammer, but the consensus recently is to go in at about two o'clock and four o'clock on the round of the hammer felt. Stay about a quarter inch back from the edge of the hammer. Experiment before you decide how much each hammer needs. Just once on each side at 2 and 4 o'clock will do, and then see how one hammer sounds. Keep track of how many times it takes to get the sound you like. Once you like a hammer, do the two next to it, and see if the sound is good. Then finish an octave and listen to it for a long time. Once you like the octave, you will know how much the rest of the hammers will need. Diminish the amount of needle pokes as you get higher in the scale, and also in the lower bass. The bass usually is not offensive and needs less voicing. The middle is usually the worst offense.

The upright piano hammers can be done in the action. Just be very careful to support the hammer as you push the needles through the hammer so you don't damage the hammer butt and flange connection.

Grand hammers are not any different in principle, but they are a real pain since you have to keep pulling the action and running it back in to test your work. There is no way to make it easy. You just have to do it right to be sure you like the results. See Chapter Five for removing and installing the action on grands.

I suggest you not go higher than the second from the last "C." It won't hurt to let them sound forth a bit more since they are so quiet anyway, but suit yourself. That's what my tailor said when I refused to pay.

Voicing Soft Hammers

Why would hammers get soft? The most common reason is because some pin headed brats thought they would make the piano into a honky tonk by shoving tacks in the fronts of the hammers. HA! So you were one of the pin heads twenty years ago, and now you have inherited the piano. Serves you right! :-)

Also, new hammers are sometimes too soft, and the tuner replacing them may not have been confident enough to risk hardening them.

There are two ways to harden hammers. The first is to steam them and iron them. If you can think of a way to steam and iron them, go ahead. That is the best way I suppose, but it is pretty hard to get steam at the hammers safely.

The other way is to dose them with Hammer Hardener which we sell in the Online Catalog.

"Brite Tone" Hammer Head Hardener- This product is used to harden hammers which are too
         quiet. This is often true of new hammers, and it will rescue hammers abused
         by brats who put tacks in the hammer face to get a honky tonk sound.
         Apply only to the top and bottom of the hammer head felt, not to the striking face.

 

Use a small brush, like a solder brush or artist's brush, and try to give each hammer a moderate soak of varnish along the top, letting it soak into the front of the hammer. DO NOT immerse the whole hammer head with the hardener. Be modest the first time until you see how it works. DO NOT play the piano until the Hammer Hardener has completely hardened. This may take a couple of days. If it is not bright enough, do it again. Better to take two or three applications than to turn the piano into a honky tonk.

Play the piano, and see if you like it. If you overdid it, simply go to the softening section above, and bring it back to the point where you like it.

What you are doing in this section of the book is considered an art.  I don't think it is that tricky, but as I mentioned above, tuners these days are fearful of the wrath of litigation freaks.  So "voicing" is often declined for some other excuse. 

  On to task 30

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