These batch of ribs are made of sitka spruce according to the shop owner Jude Reveley's design. The wood is milled at general thickness, width, and length.
Jude or maybe his friend designed a jig to press rib stocks in at an arch downward, then mill on table saw and planer. The wood will spring out with an arch on top. Still don't know why. But it works. The radius are different from rib to rib and is designed by him.
The top wide will be glued to soundboard. A razer is bent to scrape a smiling face on the glue surface. It allows glue to stay thus a strong glue joint. Each rib is numbered.
The ribs are made long, then cut to fit into piano.
The feathers at the two ends of each rib is pre-sawn roughly. Two locators are drilled and installed in each rib to mark location on soundboard, then replace by dowels. a locator hole for each dowel is drilled on soundboard. Before installing ribs, soundboard is cut into shape and glue surface sanded.
Ribs on! They are glued and pressed by air hoses giving enough pressure for a good glue joint. Next, the feathered ends will be sanded smooth and the surface sprayed.