Tuesday, October 23, 2012

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.

Thursday, October 11, 2012

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.

Friday, October 5, 2012

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.