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21-Inch Commercial Floor Sander with Sealed Motor – Mercury H-21S Hercules

The Mercury H-21S Hercules is a 21-inch commercial floor sander machine built for large-area wood refinishing and sanding in commercial and industrial settings. Its 1.5 HP sealed motor with dual capacitors runs at 175 RPM, drawing 15 amps in a sealed housing that protects bearings from dust infiltration — extending service intervals on heavy-use sanding schedules. The polished aluminum chassis keeps weight at 108 lbs while maintaining the rigidity needed for consistent abrasive contact across wide floor areas.

H-21S Motor, Speed, and Sanding Performance

  • 1.5 HP AC sealed motor with 2 capacitors — sealed bearing design blocks wood dust from motor internals, reducing maintenance frequency compared to open-frame motors on heavy sanding operations.
  • 175 RPM brush/disc speed — the operating speed is optimized for controlled material removal on wood flooring without excessive heat buildup that can scorch finishes.
  • 21-inch apron/working width — the wide working path reduces the number of passes required to cover large commercial floors, improving productivity on gym floors, ballrooms, and warehouse office spaces.
  • 15-amp motor draw — operates on a standard 15-amp commercial circuit, allowing use in most commercial facilities without dedicated high-amperage electrical service.
  • Polished aluminum chassis — lightweight structural material provides stiffness for consistent drum-to-floor contact while keeping total machine weight at 108 lbs.

Commercial and Industrial Sanding Applications

School gymnasium floor refinishing contractors use the H-21S for seasonal resanding of hardwood gym floors where the 21-inch path reduces total passes on large open areas. Commercial flooring installers use it for surface prep on wide-plank hardwood and engineered wood installations in offices and retail spaces. Hotel renovation teams use it for ballroom and event space floor refinishing between renovation cycles. Industrial facility managers use it for wood mezzanine and warehouse office floor maintenance where consistent surface prep is required before refinishing.

Warranty and What Ships in the Box

5-year warranty on motor, transmission, and chassis. Ships with: Mercury H-21S machine unit, operator documentation, and standard accessory set. Seal bearings are serviceable per Mercury's maintenance schedule.

Model H-21S
Apron Size 21 inches
Motor 1.5 HP AC, 2 capacitors, 15 amp
Brush Speed 175 RPM
Weight 108 lbs
Chassis Polished aluminum
Warranty 5 years (motor, transmission, chassis)
Brand Mercury Floor Machines

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