Here's a couple:
1.Kawai upright actions with sticking keys. They'll stick if you try to repeat the notes fast. The jacks get stuck between the letoff rail and the hammer butt. Solution- loosen the letoff rail screws and move the rail out a few mm's, then retighten the screws.
2.Wurlitzer spinets with sluggish keys. These were lubricated at the factory with a solution of naptha and silicone oil. After so many years, they get gummed up. Just need some Protek to free them up.
3.Some pianos here in San Diego were treated with oil and various lubricants by a certain technician named Mr. Rokos, former PTG member. Symptoms: Greasy feel on the tuning pins, which were smeared with lip balm. Dark string grooves on the hammers and damper felts. Fuzzy strings near agraffes on grands. Small lead squares glued on the back of keysticks. Letoff distances changed to be1/4" or more. Dull, lifeless sound from piano that seems otherwise to be good, enough crown, etc. This person's business card is often glued to the inside of the music desk and also under the bench lid. There are literally thousands of these pianos in this area, and some may have been transported to your area.
4.Action frames in grands that won't move when the pedal is pressed, or won't slide out. Leg screws of different lengths may have been mixed up with the lyre screws, etc. The leg screws in the tail of some grand pianos are a different length than the others. Some older grand pianos fitted with early player systems (pneumatic) will not allow full removal of the action. The solution is to remove the lyre to discover a block of wood which has been added to the keybed. The screws on this block penetrate the action cavity.
5.Yamaha fallboards of early models had a slow-close feature that used a spring on the bass cheek block. The fallboard itself has leather glued to a cutout in the fallboard that rubs on the spring. This leather often deteriorates or comes unglued, which makes it noisy or rough when you move the fallboard.
6.Some Yamaha grands were made with a synthetic ivory which gets dirty looking in course of time, and no cleaning attempts or sanding will renew them. Also, some Ivorite keys from these will pop off due to a manufacturing defect with the adhesive. There are warrantee repairs available.
7.Turbo-wippens from some manufacturers, with springs that are attached to the flange were not adjusted from the factory, and the leading of the keys was erratic as a result. If you find a grand piano with these wippens and the weighting of the keys is uneven, this could be the cause.
8.In some rare instances, a famous brand of pianos improperly mounted the bridge too far from the pressure bar in the top treble area. This caused the strings of the last few notes to break before reaching pitch. I confirmed this from the factory. Name is redacted to protect myself from legal implications. You know which one.
9.Some Baldwin grands had a mysterious buzzing from the dampers, due to excess glue in the guide rail bushings which made them very hard. When the key is released, movement of the strings causes the damper wire to bounce off of the hard bushings and make a buzzing sound, but not like the sound of old crusty damper felt.
10.Heavy action key weight due to heavy hammers installed where originals were much lighter. Sometimes jiffy lead weights were screwed to the underside of the keysticks to balance them. This causes the action to become very unresponsive to fast trills, though it works ok otherwise.
11.Clicking sounds coming from an action that seem to have no cause, other than they appear when the piano is played very forcefully. Gospel churches come to mind. The cause is the hammer tails were shaped before mounting, so there is an angle of the surface of the tail relative to the hammer felt. The backchecks are angled to match the tails, but this causes the hammer to move to one side when it is caught on a hard blow. The flanges are stressed by this, and can also cause the keystick to momentarily lean to one side and make a clicking sound. In normal play, you can't hear anything.
12.Woody sounding notes randomly in the treble due to glue failures of the hammer and shank. Remove the action, turn it upside down, and drip in some CA glue in the joint. Baldwins are often noted for this.
13.Some Asian grand pianos have a retainer on the cheek block screws, the intention being to keep the screw in the piano rather than fall to the floor. These retainers are like a washer that is threaded. They often prevent the screws from fully tightening the cheek block. I regularly remove them to prevent this.
14.Rattling noise from some grand actions due to loose leads in the underlevers. Sometimes the leads fall out or become stuck between the underlevers which causes two dampers to lift at the same time from one key. Pianos made overseas, usually Asian, are the usual suspects, though it can happen to any piano in a very dry environment.
15.Some Asian pianos have some loose tuning pins which were determined to be caused by some lubricants applied to plate screws at the factory, and migrated to nearby tuning pin holes in the block.
Just some of the things that I can recall.
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Paul McCloud, RPT
Accutone Piano Service
www.AccutonePianoService.compavadasa@gmail.com------------------------------
Original Message:
Sent: 05-17-2022 08:19
From: Mary Kavan
Subject: Piano info
Can any of you tell me how to find out what pianos made during a certain time have issues with such and such? Is there a book or app to find this out? Or is this learned from experience? For example: Wurlitzers in the 1980's had issues with weak pin blocks.
Thanks so much for your wisdom!
Mary