Hard-On Permanent Rust Coating for Trucks & Equipment

9/12/2025: Note: The raw materials in this formula are extremely heavy. The (5) gallon pails were over the UPS 50 Lb. weight limit. The pails are now shipping in (4) gallon pails, and the price has been reduced accordingly. 

FREE SHIPPING ON EVERY ORDER TO LOWER 48 States in USA.

Permanent Hard-Shell, Water-Based Rust Coating

Hard-On by Woolwax is a high-performance, water-based, permanent (non-removable) hard shell coating for truck frames and equipment. Originally developed as a chip guard for trailer trucks, it’s perfect for long-term applications. Very low odor, dries to the touch in about 60 minutes, and fully cures in ~72 hours. Typical protective life is 5+ years before touch-ups or re-coat.

Where It Works Best

• Ferrous metals (steel, stainless steel, cast/wrought iron) and non-ferrous metals (aluminum, brass, copper, tin).
• Adheres exceptionally well to primers/e-coat and new steel surfaces; ideal on newer vehicles with no surface rust.
• Not intended for surfaces with existing surface rust (use Original Woolwax for rusted frames).
• Excellent for high-wash areas like wheel wells.

Key Benefits & Features

• Water-based, near-zero VOC formula; low odor.
• No solvents; no petroleum content.
• Long-lasting protection against rust, moisture, and road salt.
• Chip guard & sound-deadener in addition to corrosion prevention.
• Can be sprayed or brushed/painted; compatible with most undercoating guns.
• Made in the USA.

Important Application Notes

• Dry/cure: ~60 minutes to the touch at 75°F; ~72 hours to fully cure.
• Finish: Applies dark grey/blue; dries to a matte black (this is not a rubber coating).
• Appearance: Expect somewhat uneven appearance on used vehicle surfaces—normal for this formula.
• Temperature to apply: 50–90°F. Store at room temperature.
• Recommended thickness: Apply 12–20 mils wet to achieve 8–10 mils dry after full cure. Coverage ~60± sq ft/gal (varies by surface).
• Permanence: Not intended to be removed. Be certain you want a permanent coating before applying.
• Clean-up: Wipe any excess immediately with a damp cloth before it begins to dry. Keep container tightly closed to keep air out.
• Shelf life: ~6–12 months depending on storage; do not purchase more than you’ll use within a year.

Heat & Performance Notes

• Corrosion resistance: Functions as a corrosion-inhibiting coating on properly prepped surfaces.
• Heat: Will burn off at ~140°F. Do not apply to tailpipes, mufflers, engine blocks, or other high-heat parts. (Typical heat-resistant coatings tolerate ~600–1000°F and are different chemistry.)

Topcoating & Related Products

• Topcoat options: Can be over-coated with most urethane, acrylic, or alkyd resin automotive topcoats for UV resistance or gloss (after full cure).
• Enclosed cavities: For doors, rocker panels, and frames, use a dedicated cavity wax. Recommended: Creep N' Crawl Cavity Wax.

How to Apply

• Use almost any undercoating gun (spray) or brush/roller. This is a relatively low-viscosity water-based coating.
• Apply generously to account for water evaporation; ensure you’re left with a solid dry film (8–10 mils).

Watch the Demo & Instructions

Hard-On YouTube Video

Click here for application instructions (PDF)

Gallery & Image