Many thanks to our shop owner Mr. Jude Reveley for the instructions and letting me practice. The soundboard is refinished with sanding sealer and top coat. Here we use polyurethane for sealer and acrylic urethane for top coat. Both sides of the soundboard are sprayed with sanding sealer, then only bottom gets top coat. The bridge side will be sprayed with final coat after bridge top is milled to ideal height, notched, and bridge pins installed.
One each rib, mark two places on the ends to install 1/4" diameter soundboard locator pins (shown in the mid picture). Drill with a 1/4" bit on the mark as deep as the locator pin goes.
Place raw shaped soundboard on top of piano, make sure it covers the entire inner rim and belly. Trace on the bottom of board along the outer rim, mark where belly line is with some dots. Then flip board over, place on a work surface, connect the belly line dots (shown in picture on the right). Clamp board down on work bench.
The raw ribs are made longer than needed for adjustments. Place each rib at place, mark how much to saw off. The marked line is parallel with eighter rim or belly line. Trim conservatively, a little at a time, better leaving too long than too short.
This working process was instructed by the shop owner Mr. Jude Reveley.
The shop owner designed the species, length, width, radius, etc. of the new ribs on the Steinway L being rebuilt. We are going to have the ribs made today. According to the data sheet, pick the wood - Sugar Pine for rib # 1, Sitka Spruce for rib # 2-11. Discard wood that has flaws, such as splits and knots. When selecting wood, make sure each rib is at least 2mm taller, 4mm wider, and 10cm longer than spect. The ribs will sit on soundboard with grain vertically placed. All ribs are quarter sawn.
There are quite a bit of wood residue left on inner rim after soundboard removal. We can use either sanding or teaming method to clean the inner rim surface. Use sanding when inside of outer rim is not going to be refinished. Use steam if it is going to be stripped and refinished. The first step of either method is to chisel the wood residue as clean as possible, leaving minimum amount of wood to be sanded or steamed off.
The tail of piano was cracked due to environment and released tension after strings were taken off. The shop owner suggested using of WoodEpox to fill the crack. Before filling, the bottom board, where the tail leg is attached, is taken off. The filling was done on day one, then sanded on day two when it is completely dried. Note: leave the filling higher than the surface because it will shrink when it dries. Turn vacuum on while sanding WoodEpox. It is very powdery, possibly bad for the lung, possibly very bad.
The go-bar method is a trial for now. Before, we used machine screws to fasten bridge cap to root. But to use machine screws, many holes are dilled on the cap, which weakens the bond. The go-bar method saves time on dry-fitting, also creates a stronger glue joint.
This piano does not require a new soundboard. The bridge cap was removed with a router; bridge pin holes were plugged; and surface smoothed with a power plane. Bridge cap was made from hard maple, milled to match original bridge height plus 3mm additional thickness to make room to set down-bearing later on.
To grandpa Jianzhong Wang (1927-2018), veteran of many battles, whose spirit was around during the process, who taught his children and grandchildren to be honest, and hard working.
This piano hasn't been serviced for some years. One would assume dust bunnies gather on keybed and enclosed pedal area. Carefully exam the piano, see how parts are going to be taken off. Every piano is different. If needed, take pictures of disassembly process. Remove keys makes it easier for a thorough cleaning.