Steinway D #411101 Soundboard Underside Finished

After the bridges are glued to the topside of the piano, the bottom side is ready to be finished. The first step is to cut a radius on the top of the ribs. Then nthere is a lot od hand sanding in preparation to finish being applied to the underside only.

The surfaces of the board that will accept glue need to be masked off before finish is applied.

With the underside finished, the board is ready to be glued into the piano.

Steinway D #411101 Bridges glued to board

My sound board press is unique as it also doubles as a bridge press. After appling glue, I fasten the bridge to the board with temperary screws through the ribs where dowels will be installed later. The the board and bridges are placed in the press to add additional clamping pressure along the entire plane of the bridge.

After the glue has cured, the screws are removed from the holes in the ribs, and wooded dowels are installed through the ribs and into the bridge.

Steinway D #411101 Bridge notching

After the bridge cap is sanded, templates made from the original caps are located on the new cap and the information transfered to the new bridge. The bridge is then again dry fitted to the soundboard, and the soundboard is again dryfitted to the piano. The location of the marks for the pins are checked against the plate hitch pins and agraffes, and any necessary adjustments are made. On this piano one section was out od alignment by about 1/4". Yes, the factory does make errors, and ther rebuilder has the opportunity to correct them.

After the pin holes are frilled, each unison is carefully notched on both sides. This is one of th most tiring and demanding jobs in rebuilding. Finally the bridge pins are installed to complete the project.

Steinway D #411101 Setting the Bearing

Setting the bearing on a new sound board is one of the most demanding steps in the rebuilding process. An over simplified description of setting the bearing is this: adjusting the height of the bridge caps to a height that causes the strings on the strung piano to cause downbearing on the soundboard. It is important to have enough, but not too much. It is also determinded to some extent by the amount of crown in the board. So how do I accomplish this?

The bridge caps are intentionally made thicker than the originals so that there is extra material to remove to establish the correct bearing, which also establishes the thickness of the bridge. This varies from location to location on the bridge. A notch is cut in the cap to the desired height with the use of a string and a saw. This is done at about 10-12 spots on the bridge. The bridges are then removed and the tops planed to the height of the notches cut in the bridge cap.

Bridge cap planed and sanded and ready for patterns to mark out bridge for notching and pinning.

Steinway D #411101 Fitting the pinblock

Before setting the bearing on a new soundboard it is necessary to fit the new pinblock to the plate, and to relocate the plate and pinblock assembly into the case of the piano. The plate and pinblock need to be not only in the correct position left and right, but must also be at the proper height on all planes.

The pinblock needs to be fit on two planes, the face of the plate and the flange on the plate. Fitting is necessary because the plate is made of un-machined cast iron, which means it has many uneven surfaces.It is important that this fit is precise, as it is a big factor in future tuning stability of the instrument.

Here is a photo of the new fitted block beside the original block. Note that the final step I do in fitting the block is to use a thin coat of polyester filler to insure a perfect match between the edge of the pinblock and the flange of the plate. This ensures the best future tuning stability possible.

Plate ready to be hoisted into piano case to locate pinblock.

Steinway D 411101 Bridge Caps Installed

Part of the restoration process involves recapping the old bridges. This is done by removing the original hard maple bridge caps and all the original pinning and notching. This process is complicated in the model D because the bass bridge is attached to the treble bridge. The laminated bridge body is constructed at the factory with plies of vertical maple being pressed in a caul to the "U" shape you can see in the picture. These pieces of maple are one continuous piece from note one to note eighty eight.

New caps of quarter sawn hard rock maple are then glued to the original bridge body.

After the glue has cured, the sides of the bridge cap are trimmed flush to the sides of the bridge body. The cap is thicher than necessary so that at a later time they can be cut to the correct thickness. This is called setting the bearing. After the bearing is set the tops of the bridges are finely sanded, the layout of the pins and notching are traced on the bridge and all is verified in the piano before the notching work begins. More on this later.

Steinway D 411101 Soundboard Built

when the are glued to the soundboar

Building a quality new soundboard requires a fair amount of time and wood working skills. The process is started by carefully fitting the ribs to the cut outs in the piano rim. The rib thickness and width is duplicated from the original board. The ribs are then have a radious cut in them and are feathered on the edges.

After the soundboard panel has been meticously fit into the inside of the rim, it is shellaced except where there is a glue joint for the ribs or rim. The new ribs are then indexed for locating the at the exact location to fit into the slots on the rim.

Finally the soundboard panel wood is dried to 5% EMC and the press is readied for the pressing process. I takes about 5 minutes per rib to press the board. There are 17 ribs in a Steinway D. The board is left in the press overnight to allow the glue to cure.

Steinway D 411101 Bridge Removal

After the soundboard is removed from the piano, I prepare it for use in duplicating it onto the new soundboard. This requires removing the bridges and also doing some superglue repairs to the old board as it is literally "broken" out of the piano. Especially in Steinway pianos I am very careful to accuratly duplicate the original soundboard (minus factory errors) so that it becomes a genuine duplication of the original.

PIANO RIM AND BRACING VISIBLE WITH SOUNDBOARD REMOVED

BRIDGES REMOVED FROM ORIGINAL SOUNDBOARD

Steinway D #411101 Restoration

I have recently begun a major restoration of a nine foot Steinway concert grand piano. This is a total restoration including a new soundboard and refinishing. The pictures show the varios stages oftear down.

Soundboard removed

Pinblock removed

Plate removed

Strings removed

Back on blog

Wow, It's been almost a year since I have posted anything about shop happenings. That is partly because there hasn't been a lot of shop activity the past year. But that is changing, as I have several project in progress. I will soon be highlighting a Steinway D #411101 that has just begun, and will be a total restoration and refinishing.