The Sostenuto Mechanism
  • Clean sostenuto blade*
  • Replace sostenuto bushings
  • Regulate sostenuto tabs


Beadblasting cabinet
*All cleaning is done in our custom beadblasting cabinet with a fine powder at an appropriate pressure level depending on the material. Metal bearings are polished in the vibratory tumbler.
New Custom-Built Renner Underlever System
  • Hard rock maple damper lift tray
  • Spring tab underlevers
  • Modernize spring return
  • Replace underlever felt
  • Customize spacing to keys & replace pivot block spacers
  • Verify geometry and correct as needed
  • Sand underlevers w/600 & McLube 444
  • Swedge underlever leads
  • Regulate spring tension


Original Underlever System Fully Restored
  • Clean w/compressed air
  • Repair loose and damaged underlevers
  • Check for sticky levers & lubricate centers
  • Replace underlever felt
  • Clean underlever slots & regraphite
  • Check spacing to keys & replace pivot block spacers
  • Sand underlevers w/600 & McLube 444
  • Swedge underlever leads


At Absolute Piano, every detail of this entire mechanism is meticulously inspected and addressed. Our process is listed below but in short our goal is to replace or restore every part so that everything not only looks or is brand new but works efficiently without squeaks or malfunction and remains so for years to come.
Click on links below for more information and/or photos.
Pedals & Trapwork
Sostenuto Mechanism

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