Harp Soundboard Reinforcement Bars

Since my harp soundboard is made of solid spruce, it will require some reinforcing bars. I have added two, one on top and one on the underside of the harp. The underside bar of maple, and is tapered in width as well as in thickness, being the thickest and widest at the bottom. The top is an exact match, but is made of walnut for cosmetic purposes. One of my innovations (this is not customary harp building) was to attach two spruce ribs to the top reinforcing bar. This is a take off from my piano soundboard building. Note that on a piano the ribs are on the under side, while on the harp, I placed them on the top side. This is because on a piano the pressure of the string are pushing down, but on the harp, the pressure of the strings are pulling up. The purpose of the ribs is to produce an internal stress on the soundboard that in turn produces a slight crown. The theory is that this enhances the sound produced by the board. It works in pianos. We'll see if it works in harps. The first photo is gluing the ribs to the top reinforcing bar. The second is gluing the reinforcement bars to the soundboard in my piano soundboard press. Note that the soundboard was dried to 5.5% EMC before the reinforcement bars were glued. This is an important matter that is often overlooked, as the soundboard does change dimensionally as the wood dries (more piano influence on my harp).

Mothers Day 2009

Rosanna and I had the delight of being at our daughters house for the noon meal on Mothers Day. Our two daughters were there with their families. It is always a delight to be together. It was a beautiful day to take a few pictures outside by some beautiful flowers. Our son in Michigan sent Rosanna a beautiful bouquet of flowers. Thanks to you all for making mom feel special on her special day.

Steinway O Completed

The Steinway O project is completed and is being picked up by it's owner tomorrow. The final step in the process was to put glue on the suspension dowels, and to reinstall the plate for the final time. All the perimeter bolts and plate screws were then carefully installed being careful not to mar the finish. A final check and touch up of any flaking paint where the screws were installed completed the plate installation. The final task was to reinstall the music desk slides that were removed to allow clearance for the plate to pass when removed. The owner will do the string installation and action work.

Steinway O Plate Suspension Dowels

On most pianos , especially quality grand pianos, the plate is suspended above the soundboard on "acoustic" dowels. The theory is that by being suspended in this way, the plate does not hinder the movement of the soundboard, although the movement at this location is very limited because this is directly above the rim where the soundboard is glued. Since the dowels are located under the plate at the perimeter of the soundboard, it is difficult to set their height. Here is how I accomplish this feat easily and accurately. First I drill the holes in the rim that will receive the dowels. The I insert a "dummy" dowel (no it doesn't talk) with a hole drilled in the center. A smaller dowel is inserted in the hole. It is dimensioned so that the inner dowel is tight, but still movable in the outer dowel. The center dowels are left high. The the plate is set in the piano, resting on the pinblock and the rear plate suspension bolt. The weight of the plate pushed the center dowel into the outer dowel, and stops at the proper height. The "dummy dowels are numbered and removed. Their length is measured with a caliper, and recorded. Then I simply cut and sand the real dowels to the same length. Now all I need to do is insert the support dowels in the holes with glue, and they will fit perfectly. On this piano there are 24 dowels.

Steinway O Drilling Pinblock

One of the last tasks before reinstalling the plate for the final time is to drill the pinblock. I constructed a sled a number of years ago that allows me to position the pinblock for drilling. I drill the block at a 3 degree angle. My drill press table tilts, so setting this is very easy. Also, I use a chiller to keep the bit cool, which give consistency to the holes I am drill, as well as adds longevity to the drill bit.

Steinway O Board Top Finished

After the molding are glued and the front is trimmed and sanded, we are ready for the final finish on the board top. The bridges are masked, as well as the sides and front of the case. Roughly 10 coats of lacquer are applied, until a nice build is achieved. Also note that a sound board decal is installed. This is applied on top of the schellac sealer, and covered with the applied lacquer. On this piano I am spraying the inside rim black as the piano is being refinished(by another refinisher), and this is done more easily while the plate is out.

Steinway O Plate Finished

Cleaning up and refinishing the cast iron plate adds nothing to the sound of the rebuild job, but it is the most prominent visual aspect of the rebuild job. I strive to get a great looking finish, but don't go overboard. The process in begun by cleaning the plate with scotch-brite pads and paint thinner. Note that I also sand the pressure bars to clean them and remove the groves left by the old strings.I blow the excess paint thinner off with compressed air. When the plate is dry, it is cleaned with a tack rag and sealed with a schellac seal coat. After this is dry I use a mixture of clear lacquer and bronzing powder to color the plate. When this is dry, the plate is lettered by hand, and the serial number is put on with transfer numbers. A final clear coat of lacquer gives the plate a slight wet look when dry. Note that the agraffes are removed and that I mask the pressure bars.