Archive for the ‘Repair’ Category

For very old pianos.

The walls of the drilled holes in an old piano pinblock can lose their grip on the pin. The interior walls of the hole become too smooth to hold the pin fast. There are other causes too, but the repair is the same.

Remove the pin.

Wear leather gloves.

Loosen the pin using a tuning lever. Go slowly. You will need to remove the wire from the small hole in the pin.  The wire is old and brittle. If you turn the pin too much, you will break the end of the wire. If you break it, you just made an easy repair a difficult one.

After you remove the end of the wire from the hole in the pin, slip the coil of wire from the pin. Set it aside.

Continue turning the pin until you can remove it.

Three options now.

Option 1 – (The quick fix). Cut a small sliver of aluminum from an empty soda pop can. Use tin snips. The strip of metal should be the width of 1/4 of the circumference of the pin hole, and not longer than the pin hole.

Option 2 – Use a two-part bonding glue. (Available at Walmart). Mix the two agents onto a piece of paper. Coat the pin and return it to the pinhole. Let the glue set. Use the tuner lever to “break” the bond of the glue. Restring the wire and tighten to pitch.

Option 3 – Replace the old pin with a pin one size larger.

Returning the pin to the piano.

Grand piano – Remove the action. It is VERY IMPORTANT to block the pinblock under the hole of the pin to be replaced. Use pieces of 2 x 4s to create a brace between the underside of the pinblock and the keybed. Use a small jack if you have one. Make sure the pressure of the brace does not put undo upward pressure against the pinblock. The idea here is to redirect the force of a hammer blow (needed to drive the pin back into the hole) to the brace, and then to the keybed. The brace should be snug. Wedge it into place with light taps of a hammer.  If you do not do this properly, you can crack the plate. END OF PIANO.

Place the strip of aluminum into the pin hole. With a 4-8 lb hammer, and a pin setting tool,  drive the pin back into the hole.  Leave the pin a little higher than the surrounding pins. Return the coil of wire, and CAREFULLY reinsert the bent end of the wire into the pin hole.  DO NOT BREAK IT. Slowly tighten the wire, lifting the coils of the wire as you tighten the coil is tight. Use a string lifter  tool to do this. Check the alignment of the piano wire to make sure it is exactly where it was. When the piano wire begins to tighten, use the hammer again to tap the pin so it is 1/16th of an inch above the height of the other pins. Tighten the wire and retune the string.

For an upright piano, there is no need to block the pinblock.

It is much easier just to pay a technician to do this. That is what I recommend. The tech will have special pinhole inserts that are better than using a piece of aluminum.

I have been busy the last couple of days. Miss blogging. Okay, here we go. I am putting new hammers on my piano, a 1928 Lester Grand 5’3″.  I have a few pics.

Of course, there are lots of techs who put photos up of their rebuilds. My pics differ — I don’t mind showing the mistakes I made. We learn from mistakes, right? So you may learn more too. Let’s get started.

STEP 1

Why change your hammers?

This gets technical, so let me see if I can ease all my piano-playing readers into this. First, look at one of my hammers.

Hammer Strike Line

The “strike line” is where the hammer is supposed to hit the string. See the grooves? Find the center. It has moved a bit over time. Why? Here is the technical part.

As the wool on the end wears away, the hammer swings farther. Make sense? Think about it. it is coming up too far, causing the strike line to move back. See if you can visualize that because I do not want to draw a graphic.  A hammer “swings” on an arc. Less wool at end = more distance to string. It is on an arc, so the “center” is going to change.  In this pic you can see it has shifted quite a bit.  That shift in contact point changes the tone quite a bit.

My new set of hammers must align with the “real” strike line, which is based on the extended line drawn from the center of the wooden tine in the hammer’s wool.  No, it is not easy to draw on wool. :) I do this on each of the end hammers on each section. Those are the hammers I sent to the manufacturer so a set could be created for my piano.

To begin, I want to match that strike line on the first two new hammers in the section. Now look at the FANTASTIC difference in the amount of wool on the new hammers. Wow! What a difference. I use the old hammers to mark the strike line.  I do the same thing on each hammer in each section. Easy, right?

Haha. Not easy. Not yet. Prior to this I removed the old hammers by severing the tails with heavy wire cutters.  The wood splits and you can removed it from the shaft easily.  Then I used a special tool ($$$) to trim the old glue off the ends of the shafts. No reason to replace the shafts. They are good.

  Not much to look at here.  These are dry mounted. it is an extra step. You do not   need to do this.  You can see the old guide hammers (the yellowed ones) at each section.

This is where the fun begins. the tails are squared on the ledge, and the shoulders are aligned at the top with the white part of the jig. (Photo at bottom of page)

You set each hammer so that it is properly aligned with the strike line, square, neat and glued. Notice that I am no longer using the old guide hammer.

  The result looks like this. Wish I could say it was perfect, but I did not earn that level of workmanship so I am not entitled to say that. If you look at these from different angles, what is obvious from one view is not obvious from another. However, there is more work to do getting these the way I want them. But overall, not too bad.

It isn’t just a matter of gluing hammers onto sticks of wood. There are lots of details that become apparent when you do it. I am not going to go into all of that because it is probably pretty boring.

But the overall impression is that these hammers are going to do a much better job of giving me the tone I seek when I play. They will improve the piano dramatically.

From here I will return the keys to the piano, play around with the strike line a bit to see if I am getting the best response possible. I will play a few keys here and there while pressing my thumb against the key frame to move the hammer further into the strike area. If the sound decreases, I will know that my strike line is correct. If it gets stronger — oops! More work ahead for me! Eventually I will voice the hammers to get the tone I want.  New hammers are bright and have to be voiced down.  A photo does not show how many times I will put the action back into the piano to test the sound.

After a few days I will have more to say about this project, because each you take an action, you must make several additional decisions based on what the action reveals to you.

I am inclined to say this is easy to do. In a way it is. But there is so much more to this than just gluing hammers onto sticks of wood. But you get the general idea.  If I think of a way to make the complexities interesting, I will write more as I continue.