GS 40 Stringing Begun

Today I installed the plain steel strings on the Kawai piano. Not all of the string are of the same diameter. The heaviest plain steel strings are .042". The lightest is .032".The length and diameter of the string is called the scale of the piano. This is designed by the piano manufacturer, and is typically not changed. The exception is on some poor quality old pianos, there can sometimes be an improvement in the sound of the piano by changing the scale. For significant changes, the bridges must also be redesigned, and this is not feasible in a poor quality piano. The most common change is to add several wound strings in the tenor section at the tenor/bass break. These notes in a poor quality small grand piano are often improved by adding wound string instead of the original plain steel strings.

I am not able to finish the string installation as I am waiting for the bass strings to arrive. These strings have copper wire wound over the plain steel core wire, and need to be custom made by a bass string maker. This piano has 39 wound bass strings.

GS 40 Coming Back Together

The necessary repairs have been made to the soundboard and pinblock, the soundboard has had a coat of finish, and the plate is cleaned, and the hardware polished. Having accomplished that, I reinstalled the plate in the piano. The ordered parts are to arrive tomorrow, and I hope to begin putting the new strings on on Friday. I am hoping to have the piano mostly strung before I leave for a week of vacation next week.

Kawai GS40 Work Progresses

The pictures show the Kawai piano fully disassembled. The pinblock and plate have been removed, and the the action disassembled. The final picture shows some of the most evident water damage in the high treble area of the piano. The treble edge of the soundboard had begun to come loose from the liner, and needed to be reglues. The pinblock will be reglued when it is reinstalled in the piano. Other preparation work for reassembly include cleaning the plate and soundboard, removing the old hammers and damper felts, and reconditioning the damper back action assembly. Bass strings, tuning pins, hammers and stringing felt have been ordered and need to arrive before finishing work can proceed.

New Project- Kawai GS40

Pianos and water don't mix well. Felt hardens and looses it's elasticity when it gets wet. Glue joints weaken, and music wire rusts. So when a roof leaks directly above a piano, severe damage can be the result. This is the story of the Kawai GS40 that I am presently working on. Thanks to modern glues and finishes that are water resistant, the damage was not as severe as it might have been, but it was still substantial. It will require new strings, damper felts, and hammers. A small portion of the pinblock and soundboard will need to be re-secured. The picture show the piano being disassembled.

Enjoying The Harp

Now that my first harp is completed, my daughter and granddaughter are enjoying learning to play (I am learning too). I already have purchased the plans to build a larger five octave harp. My progress is going to be slowed down by a number of piano rebuilding jobs that will soon be beginning. But it is still fun to dream and plan. It is sometimes a shame that one needs to be gainfully employed to pay the bills!

Steinway A1 Bridge Work

Recapping piano bridges is very exacting work. It is important that they are accurately duplicated, and that the wood joints are perfect. I use .030" Lexan to make patterns from the existing bridges. The first step is to remove the old bridge pins. This is done by gripping them with a Vise Grip and twisting and pulling upward until the pin surrenders it's place in the bridge. The Lexan can now be place on top of the bridges and indexed by drilling a hole through the Lexan and bridge body- all the way through. The using an awl, I indent the Lexan at every bridge pin, and finally, drill a hole through the Lexan into the vacant bridge pin holes. When this is completed, the caps are cut off on the band saw.

Next the bridge pin holes in the bridge body are fill with wood dowels. After the glue has dried, the tops of the bridge body is planed to just where all the old bridge cap is removed. Now we can lay out the new caps, by tracing the cut off caps. Care must be taken especially at the section joints for a tight fit. Lastly the caps are glued to the bridge body. I prefer Bolduc acoustic glue, as it is very heat resistant, and will not clog the drill bit when drilling the new pin hole. At this point, the bridge should be thicker than the the original, as when setting the bearing, we want to be able to remove material to obtain the desired bearing.

Steinway A1 Soundboard Pressed

After the ribs are indexed. I prepare them for gluing onto the soundboard. The cut outs for the reliefs in the ribs were saved and used as cauls for pressing the ribs. They are taped to the rib from where they were removed, and a hole is drilled through the indexing hole into the caul. a #7 bridge pin is inserted into the caul through the indexing hole, being left to protrude about 1/8". The ribs can then be dry-fitted onto the new panel, inserting the pins in the hole that were indexed into the new panel. Line are drawn to mark the location of the ribs before they are removed. the panel is now sealed in shellac everywhere but where glue will be applied. The original soundboard is used to set up the press for pressing the new board. When the panel has been brought down to 5% EMC, it is ready to be pressed. The press uses 100 PSI air pressure to clamp the ribs to the spruce panel. They are glues one at a time. Great care is taken to be sure that the ribs are placed in their indexing hole before pressure is applied to the rib. The whole process takes about 5" per rib. The loaded press is exerting about 15 tons of pressure on the soundboard.