How do I choose the right bond hardness for diamond tooling?

Use soft bonds on hard, dense concrete (high PSI) and hard bonds on soft or porous concrete. For most commercial floors, a medium bond is the safest starting point. Call us at (802) 489-0828 and we'll spec the right bond for your specific floor condition and machine.

Are these diamond tools compatible with my grinder?

US Abrasives stocks tooling compatible with all major grinder brands including Klindex, Lavina, Husqvarna, Superabrasive, STI Prep/Master, HTC, Blastrac, Diamatic, and Onyx. Tell us your machine model and we'll confirm fit before you order.

How fast does my order ship?

In-stock orders placed before 2 PM CST ship same day Monday through Friday via FedEx or UPS Ground. Most U.S. deliveries arrive within 2–5 business days. Expedited shipping is available — call (802) 489-0828 for a quote.

What diamond grit should I start with on a concrete floor?

For most concrete grinding and prep work, start with 16–30 grit metal bond diamonds to open the floor and remove coatings or adhesive. Then progress through 40–60 grit, transition to resin bonds at 100–200 grit for honing, and finish with 400–3000 grit resin pads for polishing. Your starting grit depends on floor hardness and what you're removing.

What tools remove epoxy coatings or glue from concrete?

PCD (polycrystalline diamond) scrapers and hard-bond diamond cup wheels are most effective for removing thick epoxy coatings and adhesive residue from concrete. For thinner coatings, soft-bond metal diamonds work well. We can spec the right tool for your coating type and thickness.

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Polymer Nation

Polymer Nation – P‑21 Low-Viscosity Epoxy Primer (1 Gallon Kit)

Q: Do you offer volume or quantity discounts?

Yes. Volume pricing is available on orders of 10 or more pieces of the same item. Call (802) 489-0828 or email info@fast-prep.com to discuss pricing for your crew or job.

$195.95 USD

Sale Sold out

Shipping calculated at checkout.

Product variants

Quantity

✓ Ships M–F via FedEx & UPS · ✓ Same-day shipping on orders before 2 PM · ✓ Expert support: (802) 489-0828

Product Overview

P‑21 is a low‑viscosity, 100% solids epoxy primer formulated to deeply penetrate, seal, and strengthen concrete substrates. It enhances the bond of subsequent epoxy, polyaspartic, or urethane coatings, creating a more uniform surface for decorative or protective systems.

Typical Uses

Priming interior concrete floors prior to epoxy or polyaspartic topcoats
Sealing and consolidating weak or porous concrete
Improving adhesion and reducing outgassing in decorative floor systems

Kit Contents (1‑gal mix)

Part A – 0.67 gal resin
Part B – 0.33 gal hardener
Total mixed yield: 1 gallon

Key Features

100% solids, VOC‑free
Low viscosity for superior substrate penetration
2 : 1 mix ratio by volume
Typical pot life: 25–30 min @ 77 °F (25 °C)
Dry‑to‑touch: ~4–5 hrs @ 77 °F
Accepts re‑coat in 6–24 hrs depending on temperature

Mixing & Application

Combine Part A and Part B at a 2 : 1 ratio by volume. Using a slow‑speed drill (300–450 RPM) with a mixing paddle, blend for 2 minutes until homogeneous. Pour immediately onto the floor in ribbons. Spread with a squeegee or roller at ~200–250 ft² per gallon depending on concrete porosity.

Cure Schedule @ 70 °F (21 °C)

Gel Time (1 gal mass)	25–30 min
Dry‑to‑Touch	4–5 hrs
Light Foot Traffic	12–16 hrs
Re‑coat Window	6–24 hrs
Full Cure	7 days

Available Colors

Available Colors - Polymer Nation

Downloads

P‑21 Technical Data Sheet (PDF)

Always review the full TDS & SDS before use.

Technical Specs

Grinder Compatibility

Shipping & Freight

Standard orders: Most in-stock items ship M–F via FedEx or UPS Ground. Orders placed before 2:00 PM CST typically ship same day.

Freight shipments: Heavy equipment and large orders ship LTL. Our team will contact you to coordinate delivery.

Expedited shipping: Next-day and 2-day air available on request. Call (802) 489-0828 for a quote.

Returns: Unused items may be returned within 30 days in original packaging. Custom or special-order tooling is non-returnable. Contact info@fast-prep.com to initiate.

Frequently Asked Questions

How do I choose the right bond hardness?
Use soft bonds on hard concrete (high PSI/dense) and hard bonds on soft concrete. For most commercial floors, Medium is the safest starting point. Call us at (802) 489-0828 and we'll spec the right bond for your floor condition.

Are your plates compatible with my machine?
We stock tooling for Klindex, Lavina, Husqvarna, Superabrasive, and most other planetary grinders. Tell us your machine model and we'll confirm fit before you order.

Do you offer quantity discounts?
Yes. Volume pricing is available on orders of 10+ pieces of the same item. Call (802) 489-0828 or email info@fast-prep.com to discuss.

How quickly will my order arrive?
In-stock orders placed before 2 PM CST ship same day M–F. Most U.S. deliveries arrive within 2–5 business days via FedEx or UPS Ground.

Polymer Nation – P‑21 Low-Viscosity Epoxy Primer (1 Gallon Kit)