Steinway O Broken Agraffes

Standard procedure for my shop is to always replace the agraffes on any piano over 25 years old. This is especially true for older Steinways. The original shank of these agraffes are only 7/32" instead of the typical 1/4" used today. Also the seat of the agraffe is flat which means they were often over stressed at the factory at installation. Add to that the normal weakening of the metal with age, and you have a recipe for failure if they are not replaced. On this piano, something happened that I never experienced before- two agraffes broke while removing them from the plate. Typically they break when they are under tension in a strung piano. It certainly simplifies replacement when it happens in the shop, but it is still a very tedious job because it is very easy to mess up the plate when you are removing the broken stubs.

The first step is to center punch the top of the broken stub as close to center as possible. Also, apply a lubricant like WD-40. Next, very carefully drill a hole in the stub with a 5/32 drill bit. You must be very careful to stay centered as you drill completely through the stub. Drilling off center into the plate is how the plate threads get messed up. After you have drilled through the stub, a #3 easy out is used to turn the broken shank from the plate. I am very grateful that I was successful in removing both agraffes without damaging the plate.

Steinway O Bind Bar

The bind bar is a small piece of maple that is attached to the soundboard at the very treble end of the soundboard. The glue surface for attaching the soundboard to the piano is very thin at this area. The bind bar serves two purposes. First, it insures that the glue joint will not fail in that are as six screws go through the bind bar into the piano rim. Secondly, the bind bar adds some mass to that narrow part of the board, and reflects the vibrations back in the board. On many pianos the bind bar is simply a 1/4" thick piece of wood glued to the top of the board. On Steinways it is actually triangular shaped. The end of the board is cut at a 30 degree angle to accommodate the triangular shaped gluing surface. This requires some additional work and a jig for glue up, but I do believe it does make that area of the board more vibration reflective.

Steinway O Bridges Installed On Board

In preparation for gluing the bridges onto the new board, the top of the board received it's final sanding. Then the bridge locations were hi-lighted, as well as the trim pieces. Shellac was applied to seal the board except where the bridges and moldings will be glued. Liquid hide glue is my choice for gluing bridges to the board. It has a long working time, and is easily cleaned from the bridge if it is recapped in 100 years. I put temporary screws through the dowel hole in the rib into the bridge to clamp the bridge to the board. I also press the area's between the ribs in my pneumatic press. After the glue has dried and before I remove it from the press, I install the dowels through the ribs, and into the base of the bridges. This is an exact duplication of the end result in the factory.

Steinway O Bridge Notching

Today I notched and installed the pins on the new bridge caps. Notching is a demanding job as you are chiseling hard rock maple. Also accuracy is critical for clean string termination that will produce a clean sound on the completed piano. Notching both bridges was about a 3 1/2 hour job.. After the notching is completed, the kerfs are sealed with schellac before the pins are installed.

Things Seem To Happen in Twos!

This past week has reinforced a phenomena that I have noticed through the years in my tuning experiences. It seems that things often happen in pairs. If a string breaks in one piano, I often have another one break in another piano in a relatively short time. Well, this happened to me twice within the past week. It's been a long time since I tuned a Lester Betsy Ross spinet with existing original plastic elbows (maybe several years). This week I tuned two. It has also been several years since I did a pitch raise of 200c or more, but this week I did two. It is just interesting to me now things in my world often occur in twos. Has anyone else also had this experience?

Bridges Ready For Notching

After I am satisfied that the bridge pin locations are okay on the new bridge cap, I need to prepare to drill the holes to receive the bridge pins. This is done before the bridges are notched. I use a special set of center punches to put indentations on the top of the bridge before drilling. These are 3 equally spaced punches on one tool. There are varying widths to accommodate various piano bridge designs. After the bridge pin locations have been punched, the top of the bridge is dyed black and a lubricant is placed on to of the dyed wood. Now I drill each pin hole at .003" smaller diameter than the pin being used. Ready for notching!

Steinway O- Setting the Bearing

One of the most demanding jobs in rebuilding is setting the bearing on the new soundboard and bridge. Each rebuilder has his own formula for setting the amount of downward pressure that will be put on the soundboard. The soundboard is crowned upward, and the pressure of the strings are pressing downward. Creating the correct balance between these two opposing forces provides freedom for the soundboard to vibrate freely creating a long clear ring time for the vibrating string. This formula varies across the spectrum of the soundboard- Bass, tenor, mid section, treble, and high treble all require varying amounts of down bearing to achieve a good overall balance.

To set the bearing the bridge caps are set higher than needed, and are cut down to the desired dimension to achieve the desired bearing. The recapped bridges are dry fit onto the board, and the board is dry fit into the piano. The the plate is installed as set up with the pinblock installation. A notch is cut on the top of the bridge until the desired bearing is achieved at various sections of the bridge, When these cuts are completed, the board and bridge are removed, and the tops of the bridges are planed down to the height of the notches cut into the bridges. When this is completed, the bridge patterns are placed on the bridge, and the pin locations are transferred onto the bridge. The bridge and board are again dry fit, the plate is again installed, and the bearing is verified as desirable, and the pin locations drawn on the bridge top are checked for accuracy. When I am satisfied that every thing is where I want it, the plate, board and bridges are again removed from the piano, and I am ready to notch the bridges.