Im Currently rebuilding a 1920's Cable Euphona player piano. I finished repairing loose ribs and checked the crown and the board still has crown but not alot. If I put a yard stick on the soundboard it will rock a little bit less than an 8th of an inch. Is this enough crown or shoud I attempt to increase it?

This is my first project So I will be happy so long as the piano sounds and looks better than before I touched it. My goal is to get enough experience rebuilding that I can buy a 1800's Steinway Upright(from a secret sorce that has about 40 of these) and do a complete restoration.

If the piano sounds okay, you do not need any crown.

If you want to measure something with a straightedge, it is better to measure downbearing on the bridges. If there is not enough, the strings will buzz, and you will have a better indication of loss of crown than you will get from measuring the soundboard.

You are asking the wrong question. What you should be asking is, "How stiff does a soundboard need to be?" Crown is a means to an end.... added stiffness without added weight. Theoretically, if a sound board is stiff enough, it doesn't need crown. This is, of course, a very simplified explanation. A good indication would have been checking the sustain of the notes before tear-down.

I think the sustian was somewhere around 8-10seconds max, the other piano I have has about 20-23 seconds of sustain. the biggest problem with the piano was it just didnt get loud the board didnt have the umph to it anymore.

hmm I gusse I need to get aroud to getting the plate back in the piano so I can check the downbearing I know it still had downbearing but not alot. The only thing I ever recorded was the piano wire sizes, number of unisons for each size, everything else is in my head

This kind of process is going to get you into trouble. You should be take measurements, index everything, and work from a detailed work list in an orderly fashion. Photos don't hurt, either.

If you think the board is shot, there are procedures that may help add some stiffness back. One is an epoxy treatment, which was developed by Del Fandrich; there's a series in the Journal (sometime in the mid-'90s) that outlines the procedure. Another is the addition of "riblets", which you can purchased from Darrell Fandrich; this was also written about in the Journal, but I forget when. In addition to these, you may consider a Wapin bridge modification; since best practice dictates bridge pin replacement, anyway, you might as well go Wapin, as it will add clarity and sustain to the tone.

Yeah I think a good checklist would help alot on the next one. I learn from my mistakes.

If I bump my fist on the board in various places it will ring like a tympany. Before anything was done to it, you could bang your fist on it and there would just be a thud so there is improvement I just dont know if its enough. I still have to repair two cracks in the board.

This doesn't really tell you much about how the thing is going to perform.

Agreed that orderly procedures are probably better than chaos. That being said, for me location of where everything was is more a matter of mild curiosity than anything else. My goal is to build a good piano in the old case -- not replicate what was there.

Slavish copying of existing criteria may miss the fact that:
1) The factory design may have been bad.
(Yes, even if it came from <gasp>a famous maker)
2) Even if the factory design was good, it may not have been executed correctly.
3) There is no assurance that what is being measured 80 years later is what the measurements were when the piano was made.

I totally agree with you. However, if you don't know/understand what you have in the first place, you can't improve upon it.

If I was rebuilding a piano, I'd completely index everything, AND have a complete work-list/procedure written out, regardless of whether or not I was rebuilding to spec or doing a modified remanufacturing.

I suggest that you put the piano back together and see what it sounds like. The experience will be good for you, and it will probably come out sounding at least as well as it would if you did more work on it. If you decide that you want to do more, do it on your next piano, or you could do this one over.

There are some things that you should be aware of:

It is rare that one person does everything when building a piano. Most workers have a specialty, and that takes quite a while to learn to do well. You should do the best you can, but it is going to be much, much more difficult than just reading a book or watching a video.

The best way to find out how different things affect the way a piano plays and sounds is to do one thing at a time. If you mess up a soundboard, you are not going to find out how much of a difference just replacing the strings and hammers make.

If you have no shop experience at all, consider taking a woodworking course. It will come in handy.

ThIs is probably going to be more expensive than you thought, both in time and money. Also, nobody is going to be breaking your door down to buy your piano after you have worked on it.

Besides, the real money and glamor is in tuning and repair, not rebuilding.

Thanks, I have taken Woods class in highschool which hass come in handy, I have also been a restoration shop which I'm technically an apprentice at. But hey for a Junior In Highschool I'm doing pretty good.

Ok I have a new question. I'm going to putting the plate in sometime in the next few days so I was wondering how much downbearing is enough?

How much was there before your took the tension off the strings, and how much was there with zero tension before you took the plate out?

there was almost none before I took the tension down, once the tension was brought down it came up a lttle I Have finnished regluing the ribs it looks like the board has come up more but I wont be able to tell till i get the plate back in.

Now your getting into the crown matching the plate. Have fun.

Anyone have any good methods of inceasing the down bearing of the bass bridge?

Three points well-stated. Though there are exceptions, depending upon the severity a bad factory design can often be impossible to address. Time is our most expensive investment. The challenge is knowing which ones to walk away from.

yeah im hoping my next project will go a little bit better, Im just not equiped for soundboard repair, But I will always do everything to keep the original soundboard. The piano just isnt the same, yeah it may sound better but the sound board is what makes the piano unique. If it took a 1912 steinway K and put a new soundboard in, it may as well be a new steinway K with older looks

Has anyone had any success using this method to increase down bearing? Im pretty much left with no choice there is not enough downbearing I have already shimmed the board yet, the treble bridge is almost level with the plate and the bass bridge has negative downbearing, No wonder the piano had no volume.

ASSUMING YOU HAVE NO BEARING

This gets weird. You must have let ALL the tension off the piano harp. This means this technique is ONLY to be tried on pianos under restoration of some sort. You may leave the harp, the metal plate, in the piano, but the tension must be taken off the harp completely. This is done by letting off the tension of all the strings by using the tuning pins. Do this in at least three steps, letting the tension off the whole scale in stages. The ideal is to have the strings out of the piano.

This instruction is for grand pianos, but it can be adapted to uprights if you raise the upright off the floor on heavy saw horses. This is dangerous though without the right equipment to raise an upright into the air.

REMOVE THE ACTION FROM THE GRAND PIANO.

REMOVE THE DAMPERS AND THE DAMPER ACTION INSIDE THE PIANO. If you do not do this, these parts could be damaged by the humidity added later to bend the sound board. See Chapter Five for instructions to remove the action.

REMOVE THE DESK, LYRE WITH THE PEDALS, AND ALL REMOVABLE PARTS OF THE CABINET.

REMOVE THE TOP, OR LID, OF THE PIANO, AND THE LID PROP. You want to be down to the cabinet, harp, and sound board only.

DO NOT REMOVE THE HARP. In fact, tighten the large screws around the edge of the harp if they are loose.

With the tension off the strings, find a humidifier, and place it under the piano. Secure or weight down a block of wood about 12 inches square to the floor as a point of reference. If you have carpet, you need to weight the board down so that it cannot raise later. It you have a late era home with a hard surface floor, forget the block of wood and measure from the floor.

You will now stack small blocks of wood and a wedge between the ribs of the sound board and the heavy structural wood beams below the sound board. Do this at every point where a rib and heavy wooden beam intersect.

DO NOT DRIVE WEDGES BETWEEN THE LARGE WOOD MEMBERS AND the sound board itself. This could destroy the sound board. Only put wedges between the ribs and the beams.

Do this wedge routine in a circle about midway between the edge of the sound board and the center of the sound board.

Do not drive the wedges any tighter at this time.

Get all the wedges snug in about a circle under the sound board, and take measurements.

YOU MUST HAVE THE TWO MEASURING POINTS OF REFERENCE mentioned below.

Measure VERY CAREFULLY the distance from the block of wood on the floor (or measure from the hard floor surface) to a point at the center of the sound board. Mark that point clearly.

Tack a string to the extreme edges of the sound board, possibly on a rib, secured at both ends and crossing the center point you marked. This will be a second point of reference. Make sure the string is level with all the ribs across the sound board.

Measure in 64ths of an inch from the string to your mark in the center of the sound board.

Write down both reference measurements you now have.

NOW YOU WILL RAISE THE SOUND BOARD.

Tap in the wedges around the circle of wedge points over and over in stages and measure frequently until the center of the sound board is 1/2" raised higher than when you started. Measure over and over so that you raise the board evenly all around. Do this in several modest trips around the circle of wedges.

Once you have the center of the sound board at 1/2" higher than when you started, you are ready to do the heat and humidity treatment.

Secure a home humidifier and a space heater.

Turn on the humidifier for three hours. ALSO, place a space heater under the piano on low, and cover the piano with a trap. You want the under area of the piano to get up to around 90 degrees F. So, set the space heater for this temperature, or use a thermometer to check it. This step will expand and bend the sound board upward. Wood is bent with moisture and heat.

WARNING: This process could damage the outer cabinet of the piano if it is old and weak already. YOU decide if you want to take the risk. If you are not sure of yourself, you should have a new sound board installed.

You now want to set the wood so it keeps its crown you have restored. LEAVE THE WEDGES IN PLACE SO THAT THE SOUND BOARD IS UNDER TENSION UPWARD. You are now going to dry the sound board out completely.

Remove the humidifier and heater. Place a dehumidifier under the piano, and you now want to dry it WITH THE TENSION STILL ON THE BOARD. Dry it for 24 hours with only the dehumidifier-- NO HEATER. If you can set the humidity level on the dehumidifier, set it at the low setting so it will keep the humidity at 30% under the piano. Do this again with the tarp over the piano.

After the 24 hours of drying, remove the dehumidifier and tarp, and remove wedges and blocks and see if the crown was restored by measuring again by both measuring options.

What you see is what you get. If you did not gain much then your piano is not going to respond to this technique. I would not try a second treatment.



This is an act of desperation, but it is a secret used in many restoration shops. If you determine that you have added crown to the board, you may go on with restoration. Measure again after all the tension is back if you want to, but you may find that you have gained only a little crown, or you may find the restored crown has stayed well. If you have ANY crown, do not go back and do it again.

One last suggestion. Do NOT be reluctant to call an older experienced piano technician and compare notes. This is a bit of a crazy sounding technique, and it is always good to listen to all the voices you can get to help.

You describe the condition of the board like this: "the board still has crown but not alot", "it still had downbearing but not alot", and "there was almost none [downbearing] before I took the tension down, once the tension was brought down it came up a lttle" (sic). Needless to say, these are empty words. I doubt if you are in the position to judge what is a little, what is a lot, and what is the right amount.




Your recipe sounds a lot like yet one more "I read it on the internet..." The only thing that sounds about right is when they recommend to "call an older experienced piano technician".

Ok so Im not perfect ,I made alot of mistakes and will surely make many more mistakes down the road, I am learning from my mistakes. I want to lean how to do things the right way but also to know when to improvise.

Your crowning recipe is just crazy. It's certainly not a secret procedure used in my shop.

Beyond that, I think it has already been stated that you don't need to mess with the crown on your board since there is some.

Crown is not something that you quantify and say "ma'am, your soundboard needs another 1/16" inch of crown". The difference in board performance between a little bit of crown and a little bit more may be undetectable. The difference between NO crown and SOME crown is likely to be significant.

The topic of amount of crown should only come up if you have determined for other reasons to replace the soundboard and are proceeding with that plan. If you are not replacing the board and it has crown, then just be content. There's nothing you can do that will make much difference. (BTW, I've been installing boards for over 30 years).

Bearing is another question. There again, the difference between SOME bearing and NO bearing is much greater than a little bit of bearing and a little bit more.
There are legitimate procedures to adjust bearing -- if you know why you are doing that procedure.

That procedure ain't gonna work. Please buy this, and start reading: http://www.ptg.org/Scripts/4Disapi.dll/4...;MenuKey=Menu27

Keith, I'm a bit surprised by your response. Crazy or not, that recipe is taken, word for word, from a DIY-supporting website that you described, only a few hours ago, as offering...

See "Repair and Restoration", Chapter 7, p. 57.

Well then, Could you describe one of these legitimate procedures to adjust bearing?