STI Electric Concrete Floor Grinder Junior 23″
STI Electric Concrete Floor Grinder Junior 23″ is a professional-grade surface preparation and polishing machine designed to deliver the performance of a larger grinder in a compact, highly maneuverable package. A favorite among contractors for residential garage floors, basements, and other hard-to-reach areas, it features a 23-inch grinding width and a powerful 7.5 HP (5.5 kW) WEG single-phase electric motor operating on 230V. Its variable-speed drive, adjustable pocket-weight system, and integrated 8-gallon (30 L) water tank enable seamless wet or dry operation, while the two included tool plates support six tools for consistent multi-head grinding. With approximately 60% of its weight concentrated over the grinding head, the Prep/Master® Jr. delivers superior grinding pressure for exceptional surface preparation and polishing results on projects up to 1,000 sq ft (100 m²).
Built for productivity and easy transportation, the Prep/Master® Jr. can be quickly disassembled into two sections for easier loading and handling, with screw-in carrying poles for two- or three-person lifting. Additional convenience features include a magnetic LED work light that illuminates the cutting path, an onboard USB charger, and a phone holder for improved jobsite efficiency. Measuring 50″ L × 23″ W × 48″ H and weighing approximately 455 lbs, this compact grinder is ideal for concrete grinding and polishing, epoxy and coating removal, terrazzo finishing, adhesive and mastic removal, and stone or marble polishing. Compatible with STI tooling systems, it combines reliable electrical performance, low indoor emissions, excellent maneuverability, and professional-quality results for residential and small-commercial flooring applications.
Applications
- Concrete grinding and polishing
- Epoxy and coating removal
- Terrazzo surface finishing
- Residential garage floors
- Basements
- Small commercial flooring projects
- Adhesive and mastic removal
- Stone polishing
- Marble polishing
Electric Concrete Floor Grinder Junior 23″ Main Features
- 23″ grinding width
- 7.5 HP (5.5 kW) WEG electric motor
- 230V single-phase operation
- Variable speed drive
- Includes 2 tool plates supporting 6 tools
- Adjustable pocket weight system
- Approximately 60% of machine weight concentrated on the grinding head
- Built-in 8-gallon (30 L) water tank for wet or dry operation
- Magnetic LED work light
- Onboard USB charger and phone holder
- Disassembles into two sections for easier transportation
- Screw-in carrying poles for two- or three-person lifting
- Compatible with STI tooling systems
- Designed for projects up to 1,000 sq ft (100 m²)
STI Electric Concrete Floor Grinder Junior 23″ Specifications
| Property | Value |
|---|---|
| Model | Prep/Master® Jr. |
| Working Width | 23″ (58 cm) |
| Motor | WEG 7.5 HP (5.5 kW) Electric |
| Voltage | 230V |
| Power Configuration | Single Phase |
| Variable Speed | Yes |
| Tool Plates | 2 |
| Total Tool Capacity | 6 Tools |
| Water Tank Capacity | 8 gal (30 L) |
| Operation | Wet or Dry |
| Adjustable Weight System | Yes |
| Recommended Project Size | Up to 1,000 sq ft (100 m²) |
| Dimensions | 50″ L × 23″ W × 48″ H |
| Weight | Approx. 455 lbs (206 kg) |
| Compatible Tooling | STI Tooling Systems |
Electric Concrete Floor Grinder Junior 23″ Video
Prep Master Junior Floor Grinding Machine Features
There are no reviews yet.