Select wood according to the species, width, and length on the design sheet created by shop owner Jude Reveley. Cut each rib 20cm longer than target length. Place in rib milling jig.
Clamp raw rib tightly into jig using caul of target radius. The radius on ribs in one piano at the shop ranges from 4 to 15 meters. The jig is 74 mm thick. Calculate the target rib height and protrusions from jig, give about 2mm room, then saw. Finish rib height by going through plainer.
The top side will be the glue surface to soundboard. Scrape a smiling face with razer blade to hold glue. Mark number of rib, release from jig, compare radius with caul. This one looks ok.
Trim each rib to target width. Everyone is slightly different.
Clean inner rim and rib slots. Place ribs and saw to target length. If ribs wider than original slots, chop and trim slots to fit ribs from the new design.
Trace feathers according to the original ribs, saw 2mm+ outside trace line, and fit into piano again.
Mark two places for locator dowels on each rib. Use the jig. Drill locator holes with 1/4" bit.
Insert locator pins on ribs, place new soundboard in, press down with go bars, press ribs hard on soundboard to transfer pin marks. Release soundboard, check that all rib location marking pins did their job.
Remove pins from ribs, insert 1/4" dowels, trim to uniform length. Drill locator holes on soundboard with straight jig, be careful not to drill through the board. Sand the surface with 220 grid sandpaper.
Set up air clamps, dry fit each rib before gluing on. Clean glue squeeze outs using a wood stick or something not very sharp.
Finish cleaning with a hot wet rag. A thorough cleaning makes sanding much easier later on. We use Titebond 50 for this job. Clamping time is 30 min. With limited amount of clamps, one rib is pressed for more than 30 minutes, then the clamp is moved to glue the neighbor rib. Small shop.