Prep/Master Jr. – 23″ Electric Concrete Floor Grinder

High-Performance Grinder for Residential & Small Commercial Jobs

Our customers’ favorite little grinder! The Prep/Master® Jr. works extremely well in small, hard-to-reach areas that need a compact machine — perfect for residential garage floors and basements. It’s built for professional surface preparation and polishing, with a 23-inch grinding width and a powerful 7.5HP motor for consistent performance on small commercial and residential projects.

The moveable pocket weight system adjusts head pressure to the job, and the standard water tank makes it easy to switch from dry to wet work. Recommended for project sizes up to 1,000 SF (100m²).

Ready to put the PM Jr. to work? Call for pricing and availability, or request a quote — you’ll talk to a real surface-prep expert, not a call center.

New to grinders? Read our guide on choosing the right one!

Improved and Tested Before It Ships

The Prep/Master Jr. isn’t a cheap import pulled off a shelf. Before it ever reaches you, we improve it:

• Upgraded couplers — we replace the cheap rubber couplers with better, more durable ones built to hold up to real work
• Better tool plates — for more reliable tooling attachment and performance
• An improved water valve — for better control during wet grinding
• Every component tested — we test every component and run the machine before it ships, so it arrives ready to work

And it doesn’t stop at the sale. We back the Jr. with genuine parts, real service, and surface-prep experts a phone call away — support a cheap import simply can’t match. Weighing the Jr. against a cheaper import? See what you’re really paying for →

Specifications

• Recommended Project Size: up to 1,000 sq ft
• Working Width: 23″ (58 cm)
• Motor: WEG 7.5 HP (5.5 kW), single phase
• Voltage: 230V
• Weight: approx. 455 lbs (206 kg)
• Dimensions: 50″ L × 23″ W × 48″ H

Applications

• Concrete grinding and polishing
• Epoxy, coating, adhesive, and mastic removal
• Terrazzo, stone, and marble finishing (with proper tooling)
• Small commercial and residential flooring projects

Jr. or Sr. — Which Prep/Master Is Right for You?

• Prep/Master Jr. (this machine) — 23″, for residential and small jobs up to 1,000 sq ft; garages, basements, tight areas
• Prep/Master Sr. — 27″, for larger commercial and production jobs up to 5,000 sq ft

Not sure which fits your work? Call us and we’ll help you choose.

Financing Available

Spreading the cost into manageable monthly payments can make the Jr. more affordable than you’d expect — and smarter than buying a cheap grinder twice. Ask about our financing options →

Warranty & Support

Every Prep/Master Jr. is backed by our Prep/Master® warranty and our in-house service and parts — so you’re supported long after the sale.

Frequently Asked Questions

What size jobs is the PM Jr. best for? Projects up to 1,000 square feet — ideal for residential and small commercial work like garages and basements.

Can it polish concrete? Yes — with proper tooling, it handles both grinding and polishing.

What power does it require? 230V.

What surfaces can it handle? Concrete, terrazzo, marble, and stone.

What makes it different from a cheap import? We upgrade the couplers, tool plates, and water valve, test every component before shipping, and back it with genuine parts and real support.

Order Your Prep/Master Jr. Today

Call (815) 941-4800 x 1 or fill out our contact form. New to grinders? Read our guide on choosing the right one. See our diamond tooling and dust collectors.

Item #823752250