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66. Piano Wood Frame Loose on Bottom


The massive wood frame in back of the piano is usually going to last for a hundred years without trouble. But, there are exceptions. The worst situation is when the lower rear parts of the frame come loose and let the piano settle. This is because the rear casters are mounted in some of the parts which like to come loose.

The worst at this are the old uprights, Hall and Stetson. There are others also. This job is not hard to understand for the do-it-yourselfer. You need to get the wood parts back into their original position and secure them with big lag bolts.

To do this, lay the piano down on its back. Three men are needed to do this safely.  Remember to put the two 2 X 4s under the piano when you do this so you can get your fingers under it later to pick it up.

With a hammer, tap the blocks of wood which hold the casters back into place. Try to work some Elmer's carpenter's glue into the process. When the glue has set up some, drill holes through the wood which has NOT moved, drilling into the wood which moved or broke loose. Drill a hole for the shank of the screw, and a second smaller hole for the thread of the screw.  You may have to procure extra long drill bits for this job.  The guide hole should be pretty close to the size of the screw threads because you are working with old dry hardwood-- probably oak.

I like to counter-sink the heads with a flat wood bit, about one inch size, so that the bolt heads do not hang out and look ugly. Use hex head lag bolts, and put a one inch washer under the heads. Tighten them snug, but beware of breaking them. In a couple of months give them another turn.

If there is no good way to secure the rear blocks from behind, you will have to come into them from the side of the piano. This means an ugly addition to the outside of the piano where folks can see it. You have no choice. You could counter sink the bolt head, and put a wood cap over the hole which you can get at the hardware store.

Make the counter sink hole one inch in diameter by using a flat wood bit. Use a one inch washer under the bolt head, and this way the wooden cap will fit nicely if it is also one inch. DO NOT glue the wooden cap into the counter sink hole tightly. You will want to remove it some day to take a turn or two on the bolt.  Use the yellow mustard based rubber cement to glue in the wood plug. 

When you set the piano up again, you may want to add another lag bolt to a point which was covered when you laid it down. Don't shortcut this work. You will be sorry on moving day.

Have the bars coming out of the front of the piano come loose? These are the bars which hold the front casters and run back into he lower box of the piano.

To get them back tight, lay the piano down as above. You have no choice but to put two bolts through the lower cabinet, from outside to inside, through the bars. Only this time you should go all the way through the bars and secure the bolts with nuts on the inside of the box. Use large heavy washers on both ends of the bolt so that the hardware doesn't imbed itself into the wood and loosen later. It is not necessary to glue these parts, but it is helpful.

Again, read the counter sinking suggestions above. All instructions there apply here, but countersink a minimum since you must avoid making the cabinet wood too thin to hold the bolt..

The results of this work are not pretty, but if you leave this job, the whole lower box could one day rupture beyond repair. Most of your guests will not notice anything anyway if you don't mention it, especially if you follow the counter sinking suggestions.

There are other structural problems which can happen. If you see a problem in the middle to upper frame in the back, ask your mechanical friend to come over for pizza, and see what he thinks will secure the thing. Use the lag bolts again, but be very sure you are not involving the sound board in any on your inventing. That would be disastrous.


There is a problem which can come up in a grand piano. The symptom is this-- The desk, that is, its level mounting board, will not hang right on the two runners at the ends. It may even fall off at one end. This is because the frame of the grand has sprung or come loose in the area of the front keys.

This is serious, but there is hope. Like the story above with the old upright, you may have to make a compromise with the beauty of the piano.

With the desk removed, look at the pin area. There is a wooden bar between the keys and key cover and the tuning pins. This is right up in your face as you look at it, and you will notice that the metal frame comes up under that piece of wood.

Meditate on this area for a way across the top front area right between the tuning pins and that top wooden bar.  Next, meditate on the Illustration for a while. 

You will have to measure carefully. You want two pieces of "all thread" rod, three eights of an inch in diameter. They must be cut so that they can run from the outside of the box on each side and meet each other at a turn buckle in the middle. This turn buckle will be used later to add tension as needed.

If you try to do this with a one piece assembly, you will be in trouble when you need to tighten it later. The ends of the rod will start hanging out the sides. Ugly!

Read the upright piano section above noting how to do a counter sinking. You will need to do this by drilling holes through the side of the piano for the rods. You will have a nut and washer on the end of each rod to secure it.

Now, here is an important item. Try to locate the ends of the "all thread" so that they come together at the turn buckle at the area between the middle tuning pins and the bass tuning pins. This will make sure that the turn buckle does not get in the way of the tuner when he tunes the piano. Many grands have a sort of recessed well there where the turn buckle can be adjusted and the tuning pins are not present.  Also, keep the tuner in mind when you drill the holes. You MUST NOT let the rod come any closer than three eights of an inch from any of the tuning pins. If you cannot avoid this, do NOT do this job.

The diagram will help you to understand what is going on. If a front side of the piano box is badly broken loose, you will have to get under the piano and see where you can do the same rod and turn buckle trick under there. You are dealing with a lot of tension, so two rods may be needed.

When you tighten up this mechanical device, you may not be able to close the broken area completely without stripping the threaded rod. Don't worry. At least you have stopped a process which could destroy the piano later.

 On to task 67.