A sticky note is one in which the note does not respond quite as it should; that is, the note can be played only once. There are many causes of sticky notes. Common symptoms, causes, and cures (in upright pianos) include:
• The key itself is physically stuck down• The front of the key is fouling on the slip rail• Slip rails is warped—shave some off or reposition it• The front bushings are binding on the key pin• The key pin is rusty—clean or replace• The bushings need lubricating and / or easing• The key is free but the action has not returned• The note is played and the key returns but when struck again the note does not sound• The hammer has not returned• The tape has broken—replace• The hammer flange is stiff—lubricate or repin• The butt spring is broken—replace combination of the above• The jack has not returned under the hammer butt• The jack (spiral spring) is broken—replace• The jack flange is stiff—lubricate / repin• The key capstan is adjusted too high—adjust down• The wippen has not returned to its correct position• The wippen flange requires lubrication / repinning• The front of the wippen is fouling (the frame sometimes)—shave some off• The damper spoon is corroded / caught against back of damper bottom (underdamper only—replace damper box cloth and or clean / replace spoon
If in doubt, call us for a consultation.