The marron colored hitch pitch pin felt needs to be replaced. There are so many holes on it to be transferred on new felt. For accuracy and better fit, the shop owner suggested that we use mylar as a templet. With a good hands on skill, the mylar step can be eliminated, not here, though...

The plate has been refinished, all shiny shiny. Spray adhesive on back of old felt, glue it on a piece of mylar or similar material that's on the stiff side. transfer holes through old felt to mylar, try on plate for fitting. If some holes don't fit, mark and re-punch holes till the template sits flat in position. For the missing holes on old felt, the mylar is placed on top of those hitch pins, a pencil is used to rub from top to make a mark for the punch.

Spray adhesive on top of template, glue new felt on so the glue is on the bottom of the new felt. Flip up side down so the mylar is on top now, transfer all accurate holes to new felt, fit again on plate. Glue down the two ends with felt glue. The rest of the felt will be pressed down by strings. 

Pinblock fitting to plate flange is here:
https://www.yunspianoservice.com/work/pinblock-for-steinway-l

This is when the 5 layer pinblock is glued up and fitted to the plate flange. 

Use a transfer punch to mark tuning pins and webbing screws. Drill webbing screw pilot (body) holes through plate for accuracy. Be careful not to drill too deep, or it will be easily stripped when turning screws in.  

Set up drill press. That hose blows air out to cool down drill bit. Drilling into laminated maple can create a lot of heat. Tuning pins are tilled 5 to 7 degrees towards the front of piano, so the drill press is tilted this way, as well. When drilling for webbing screw holes, be cautious that the bit is in the center of pilot hole. Also till drill press back to 90 degrees before drilling any screws holes.

The screws can be in different sizes. Pay attention to use the right drill bit for each screw size. After all the drilling, check if every hole is opened up. Clean drill bits thoroughly for the next person or use.

We use a router to cut from bottom of pinblock. Mr. David Betts called this thing widow maker. I do express my deep gratitude to Mr. Router before operating him. Hold router firmly with two hands , turn it on by thumb while holding handles tightly, at bass of piano, let the metal plate rise against stretcher straight up, cut upwards till baring hits the bottom of stretcher. Move slowly to treble. When the right side handle hits treble end of piano, move router straight down, turn it off with thumb while holding handles tightly. Hold it till the blade stops spinning completely. Use a sawzall to cut two end of pinblock, 3" from the case.

Remove main part of pinblock with a heavy hammer. Drill out dowels that were fastening the block to case.

Remove the remaining chunk of pinblock with large chisel and hammer, layer by layer. Do not try to take off too much wood each time, it is not only harder to do, but also causes damages to tools, piano case, or people.

The leftover veneer on stretcher can be removed mostly by chisel if old glue is not rigid and easy to peel off. If the old glue is stubborn, soak this layer of veneer with hot water and rag, chisel off when soft. Finally, as always, clean and resharpen tools.

You live in us, David, forever and ever and ever and ever...... Pictures taken 2016 at North Bennet Street School, Boston MA.

The lyre was water damaged. Rust everywhere. Felt on metal turned into rust and ate chunks off metal pieces.

Use bead blaster to remove rust. The surface on brass pedals didn't look so well after blasting (left piece in middle picture), Scotch-Brite could put some even grain on it (mid and right pieces in middle picture). Screws are grabbed onto drill press. Turn press on, press down lightly onto sand paper glued on backing boards, the screw surface will be clean with less effort, thanks to our boss. 

Spray a coat of finish on metal to prevent or slow them from rusting again.

Open up the cup on rare end of pedals with 1/2 drill bit or mill, cut and insert leather disk, then fuel hose. The fuel hose is very resilient and strong. Hopefully it'll last for a very long time. If using rubber, it may harden in several years.

Remove old raviolis from bottom board, drill for carpet tacks with a very thin bit, fasten new raviolis.

Remove old felt at the back of lyre where pedals stick out, glue on new felt.

Remove felt on pedal rod guide rail, rebush with new felt.

If replacing screws but couldn't find new screws at the same size, replace with bigger screws and tap for it. Also make sure pilot holes for bigger screws are opened up with a drill.

Reassemble parts, make sure screws are tight, pedals with no side play but rotates up and down firmly.

The process is recorded on different sets of dampers. We've tried all methods of damper felt removal that the brains could storm about. This is the fastest and cleanest way so far. Pull off felt with a plier dry, drop wall paper remover on old glue residue from note 1 (note 67 is usually the last note that has dampers. Steinway D is up to note 71), once all dampers are wet, the first damper received wall paper remover is ready to be worked on, the glue is soft enough to be scraped off. clamp damper head and scrape remaining felt and glue off. 

Hammer numbers on each damper head, then remove old damper wire by pushing out the fluted top part. These wires are too rusty to keep. If wires are in good condition, they can be polished.

These damper heads were refinished per customer's request. We scrubbed the old finish with 3M Scotch-Brite to smooth them out then sprayed them, this batch took 4 thin layers of lacquer. They look better with several thin even coats than one thick ugly coat.

Take out new wires, bend the top down a bit for easy installation. Without bending, the fluted top always want to flatten itself. Hammer the wire top into damper head, then press in with homemade device (thanks to our boss). Press firmly till the wire is solidly bonded in the head.

Work (crime) scene. The dampers are now ready to be trimmed, bent, and installed into piano ^ ^

A bridge pattern is made before bridge top is taken off. The pattern will be reference to new bridge pin patterns once bridge top is replaced. Remove all old and rusty bridge pins, take out pre-sliced mylar strips and cut to fit on the bridge top. Each piece of mylar shall over lap to secure each other. Plug in soldering pen to allow it to heat up.

It is better to get some black paint transferred onto mylar pattern from old bridge top. Spray mylar with adhesive, then lay on bridge and rub vigorously with a piece of metal dowel/stick to let the black paint stick onto mylar.

Take the hot soldering pen, carefully punch into each bridge pin hole. Note, the front and back holes are drilled at opposite directions. Melted mylar sticks on soldering iron, wipe constantly for the accuracy of the pattern.

After all holes are poked, double check if there is any part missing. Cut 2 sides of the pattern with a razer blade, blade bottom pressed against bridge wall.

Number note numbers, write piano make and serial number on each section of mylar incase any piece gets unglued or fell off. Carefully take the pattern off bridge and store till new bridge top is installed and new bridge pin pattern ready to be laid out.

Remove old key buttons on router table with a jig, or clamp key on vise then remove key buttons with a felt knife.

Trim key button stock to width, route decorative edges, and mark them according to angle of keys.

On a bandsaw, cut off each key button according to the angled lines marked, set up jig to glue the buttons, apply hot hide glue for this job. The glue sets in seconds, so work fast but as accurately as can be. 

For each round of gluing, work on every other key because the buttons are cut wide to give room to be trimmed flush to two sides of keys. Let them dry for an hour, then rough trim on bandsaw (not shown in pictures). The last pass is to sand them on an clamped up side down Festool detail sander. The sander is very heavy, and gets heavier as work goes by. This way, one can work fast and save energy.

Lubricate areas where strings will go over, here shows front counter bearings lubed with ballistol. Cut and glue on felts for the strings also. Install nosebolts and place plate in piano.

turn up nosebolts to just touching the plate, tighten all webbing screws and perimeter bolts. Align agraffes so they are perpendicular to the strings. 

One piece of wire makes a loop to make two strings. Cut string end to length. 4 fingers out of a small hand work well here. Make coils with coil maker or other tools.

Pound down tuning pins with hammer or air pounder. After a loop is installed, lift strings and tighten them. Make sure coils are tight, no gap between coil loops.

If possible, tighten coils with coil tightener, squeeze beckets tight also.

In order that the strings stay put, secure them with a clamp at hitch pins. On each end of a loop, beckets shall face the same or similar direction. But this is only cosmetic. We are slowly making progress.

Wave string braces on the back scale of tenor strings to reduce noise or over tone.

On treble side where there is no agraffe, use scale copied from action as string spacing reference, secure spacer on each note/group of 3 strings, tap with hammer till center string is sitting on mark on the scale. Refine spacing with note width gage and a not-sharp-at-all screw driver to make sure each note is at the same width.

Install base strings, one at a time. Protect soundboard with anything on hand.

Install bass string braces then take a long break before chipping piano to pitch, tighten coils and beckets, even out tuning pin height, and so on.

WNG backaction is made of aluminum. We made a scale stick according to top action. Transfer the marks/spacing to backaction rail, then drill open with 3.3mm drill bit.

Tap for damper tray flanges with M4.7 thread tap, install flanges. On damper tray, mark 10mm from bass edge, then mark where flange screws will be. Drill with 3.3mm bit.

Tap all drilled screw holes with M4.7 thread tap. Apply tapping fluid for every 3 to 4 holes, without fluid, it will be very hard to tap and bit can break.

Mark where the tray ends, cut with metal cutter, clean cut surface with file.

Install damper posts and damper tray felt.

Use a square, check if under levers are square. If not, remove under lever, shim under screw surface, screw back, and double check.

Install damper tray. Note that a slot to clear sostenuto monkey was cut off on damper tray. Old and new backaction comparison. At least we don't have those swelled leads anymore.