Replacing an Upright Piano Pinblock

The project described below was recently completed on an 1888 Everett Upright piano. The original pinblock was seriously defective, especially in the treble section: about half the pins had insufficient torque to hold the strings at concert pitch. Clearly, the pinblock needed to be replaced. Our clients had a strong attraction to this beautiful vintage piano, and they were willing to invest in having this major improvement completed. We also reconditioned the action of this piano, and we were confident that the outcome would be a fine musical instrument.

1 – Softening and cracking of the pinblock has resulted in the tuning pins being too loose to sustain pitch. We will need to make and install a new pinblock.

2 – We dismantled the piano, removing the action, the keybed, the pedal board, the back of the lid, the strings and the plate--leaving the soundboard and pinblock exposed.

3 – We carefully marked the locations of all holes in the pinblock, the upper bridges, and the 1/4"-thick bass pinblock cap.

4 – The main tool for removing the pinblock is a 3/8" drill bit 18 inches long, and a special jig designed by Andrew Bolduc of Quebec, Canada.

5 – With our skill-saw, we cut two grooves 2" deep into the pinblock, just above the glue-joint, leaving a "guide hole" the same width as the drill bit. Then we used the Bolduc Pinblock Extractor Jig to drill a series of parallel holes through the pinblock, extending just above the soundboard.

6 – For drilling the last four holes just inside the sidewalls, we disassembled the jig and reassembled it using only the right or left two screws. This enabled us to cut into the pinblock right up to each sidewall.

7 – We drilled a series of vertical holes through the pinblock at each end. . .

8 – . . . and we cut through the pinblock with our skill saw at each end as close as possible to the sidewalls.

9 – Finally, we cut through the pinblock just above the soundboard, being sure not to cut into the soundboard material.

10 – We pried the main section of the pinblock upward with long screwdrivers and a crowbar, leaving the lower half of each drill hole in the piano.

11 – Using hot water, a steam iron, and chisels, we carefully loosened the glue joint under the remaining thin layer of the old pinblock.

12 – We cleaned the surfaces on which the old pinblock had been installed, preparing a flat surface for installing the replacement pinblock.

13 – We repaired the soundboard and refinished it with sealer and spar urethane.

14 – After cleaning the plate and the plate pins, we re-installed the plate in the piano, placing all bolts in the original locations.

15 – We cut a piece of new pinblock material to fit precisely between the two sidewalls and then fit the lower edge to the upper edge of the plate.

16 – Using the mylar pattern to plot exact locations, we installed a new 1/4" cap in the bass area, and we drilled eight holes: for the action bolts and for the large pinblock bolts. Before drilling tuning pin holes, we refinished the new pinblock with three coats of sealer, rubbed down with extra fine sandpaper and steel wool.

17 – After taping the mylar in place and positioning the upper treble bridge, we punched tuning pin-size holes through the mylar template, marked the holes, and enlarged the centers with a countersink bit.

18 – We followed the same process in the bass section of the pinblock.

19 – We drilled the tuning pin holes with a .251 bit at a 6-degree angle, and with a compressed air-blower attached to the drill to remove wood and cool the bit during drilling.

20 – Using the pressure bar as a template, we drilled screw-starter holes through the upper bridge into the pinblock, and we dry-fitted the pressure bar.

21 – We installed new bridge pins on the upper bass bridge.

22 – After spreading a thick layer of glue on the "pinblock bed" and inner sidewalls of the piano, we clamped and bolted the new pinblock in place, letting the glue dry overnight.

23 – Next morning, we removed the clamps, and we installed new understring felt.

24 – After restringing, we installed the pressure bar over the treble section and positioned it to press down on the strings at the depth required for keeping the strings in place. Project completed! Now, to action reconditioning. . .