Grand Piano Restoration: Action & Keyboard

Remember to take some of the general measurements of the action and keyboard. Most important are the original measurements within the action and keyboard geometry and the tolerances for how it plays at the moment with all of the worn parts; not too important to be concerned about the string line as the plate will be raised for re-gilding. 

Because this action has a partial hammer set replacement there will be difficulty in obtaining original geometry for the extreme treble areas. 

Lots of the common repairs required here; all keyboard under felts, a full set of key bushings top and bottom, back check leather replacements, whippen heel, drop screw and let-off replacements, along with hammer shanks, flanges and hammers. 

Now that the entire instrument has been dismantled, there are several stations to work at, the action and keyboard restoration, the cabinet and woodworking, then the fixed structure of the instrument, the plate, sounding board, bridges and pin block. This prevents a work stoppage in case of machinery breakdown or lack of proper parts; one can switch to another area to continue working.

Same photo set starting at photo 63.

Action and Keyboard

Grand Piano Restoration; Understring Felt and Bearing Bars

Following string removal in years past, time would be spent marking, measuring, and recording the distances between the bearing bars and the hitch pins. As the plate is being re-gilded, all of the existing marks and measurements for bearing bar placement, strings sizes, manufacturer decals, and any other plate markings will disappear.

These days I use a digital camera to record a photograph of each bearing bar and its distances from the corresponding hitch pins. Then following gilding, the bars are replaced in the exact position as previous.

The under string felt is removed and stored for matching up to new cloths at a later date previous to stringing.

Same photo set starting at photo 55

Understring Felt and Bearing Bars

Grand Piano Restoration: Letting the Plate Down

Most of the instruments that come to the shop for restorative work have been up to pitch for a long period of time. The entire piano framework has been under tremendous strain for many years; decades in fact.

When letting the tension off the plate, this must be done safely as the sudden release of pressure could cause an unbalance of the plate or other structural components of the instrument. Very much like unbolting a car tire the weight or pressure must come off evenly distributed. With almost 20 tons of pressure on the framework one cannot tell if major structural components have deteriorated to the point of collapse and are being held in place only by the tension applied.

Over the years I have used this procedure successfully time and time again. It is the safest way I have found to let down the tension from the piano.  This task is best completed using a 4ths and 5ths temperament.

First take middle C and tune down so that middle C becomes the same as the B below. Then tuning in octaves tune all of the C’s to that pitch or tune all of the C’s to the B below. The result is that middle C is now a full tone lower than originally.

Next tune the F below Middle C to the E below F. Then follow the same procedure used for C.  Next, tune all of the F’s by octaves or tune the F’s to the E below. After F, then the G below middle C down to beat less, then the D above middle C down to beat less, then A below and so on. Work your way around the temperament until you have completed the temperament.  Each time you lower a key in pitch do all of the same keys of the keyboard. It is not important to fine tune as you go. Just rough in the keys and make them close to the pitch you are looking for. 

The end result will be that the entire piano will now be a full tone lower that A440 which means that you have released approximately 4 tons of weight off the iron frame.

Now return to middle C and begin again by lowering the pitch to the B below. Work your way around the temperament using this new pitch. At completion of this second step the piano will now be two full tones lower than A440. 

From here you can take a T-handle or a stringing hammer and turn the tuning pins one half turn so the remaining tension is released.  This process once learned can be completed in about an hour.

Some photos of the process; please begin at photo # 47

Piano String Removal

Grand Piano Restoration: Dismantle, Label, and Store

The piano will be apart for a period of time. It will be impossible to remember the way things came apart exactly and this is why it is so important to take a lot of notes, and label things as to where they are located and how they came apart.

Take notes or photographs of all procedures.

The piano arrived in the usual way; brought into the shop and set up on its legs by the movers. I place my grand’s on a shop truck that was built out of heavy timber. This sets them up high off the floor so I can work on the insides without bending over all day long.

Here are some early photos of the cabinet dismantle. Please start at photo number 35.

Dismantle Label and Store

Grand Piano Restoration

Recently I was contacted by one of the educational facilities here in Vancouver with a request to restore the grand piano located in the auditorium. After inspection to determine if this instrument was a worthy project, the administration accepted my restoration proposal.

Over the next two months this instrument will be dismantled completely, then re-assembled with the new parts and components required to complete the project. 

Built in 1911 this is a 6 ft. (1.8m) grand in original condition. While the structural components of this piano are in relatively good shape, the cabinet and all of the moving parts that make up the action and keyboard and the string work are all signifigantly worn.

There will be postings to this blog several times a week with new photos of the repairs and techniques performed. Gradually over the next 10 weeks this project will be completed.

As school is now out for the summer break we will begin when the movers bring the instrument to the shop. Most likely this will be in the next couple of days.

Here is the photo set of the piano in the condition that it was found.  Lots of repairs to do!

Grand Piano Restoration