Short answer: it shouldn’t, if you apply it correctly and use it on a suitable surface. RAPTOR paint (often called RAPTOR liner) is designed to be tough and slightly flexible, so it resists the kind of cracking you see with brittle coatings. Still, any coating can be pushed past its limits. In this guide you’ll learn what RAPTOR is, how to spot true cracking versus other failures, what typically causes cracks, and exactly how to prevent and fix them. By the end, you’ll know what’s normal, what isn’t, and how to get a long‑lasting finish.
What RAPTOR Paint Is And How It Performs
Urethane Bedliner Characteristics
RAPTOR is a two‑component polyurethane (urethane) bedliner/coating. Once mixed with its hardener, it cures into a dense, chemically resistant film with texture. It’s formulated for impact resistance, abrasion resistance, and a level of flexibility that helps it shrug off the knocks that would chip a conventional paint. You’ll see it used on truck beds, 4×4 exteriors, marine decks, machinery and utility trailers.
It bonds well to properly prepared steel, aluminium, fibreglass/GRP, certain plastics, and even wood when primed correctly. It also offers decent UV stability compared with many bedliners, although colour fade can occur over time, especially with darker tones in full sun. Importantly for our question, the cured film isn’t brittle: that’s a big reason genuine cracking is uncommon when everything’s done by the book.
Balancing Flexibility And Hardness
Coating design is a trade‑off. Too hard and it shatters. Too soft and it scuffs and creeps. RAPTOR sits in the sweet spot for utility use: hard enough to resist abrasion and chemicals like diesel or salt spray, yet flexible enough to move a little with panels, temperature swings and vibration. That balance is why you’ll usually see dents and scrapes before you see true cracks. When cracking does happen, it’s more often due to application or substrate issues than the product itself.
Cracking Versus Chipping, Peeling And Crazing
How To Tell The Difference
• Cracking: visible, often network‑like fractures through the coating. You can feel ridges/edges: lines may run in a pattern and can propagate.
• Chipping: localised impact damage down to primer or substrate, usually with a sharp edge where a stone or tool hit.
• Peeling/delamination: sheets or sections lifting from the surface, often starting at an edge or around a contaminant: the back of the lifted piece may be clean (poor adhesion) or show primer transfer.
• Crazing/micro‑checking: very fine, hairline surface lines that don’t go fully through the film: often linked to solvent entrapment or over‑baked topcoats.
Why The Distinction Matters
The fix depends on the failure mode. Cracking and crazing often point to film build, cure or compatibility problems. Peeling screams adhesion/prep issues. Chipping is mechanical abuse and might be solved with touch‑ups or a thicker film in high‑wear zones. Misdiagnose it and you risk repeating the same mistake on the repair.
Common Causes Of Cracking
Surface Prep And Substrate Compatibility
RAPTOR wants a keyed, clean, compatible surface. Problems start when you apply over:
• Shiny, un‑abraded paint (no mechanical key)
• Contaminants: silicone, oil, wax, salt, moisture
• Incompatible primers or uncured coatings beneath
• Highly flexible plastics without adhesion promoter
On some substrates (bare steel, aluminium, galvanised, fibreglass), an appropriate primer is strongly recommended. If the underlayer is too brittle or moves differently than RAPTOR, you can get stress that shows up as cracking at edges or along panel flex points.
Mixing Errors, Pot Life And Cure
RAPTOR is a 2K product. Wrong ratios, poor mixing, or spraying beyond pot life cause under‑cure or uneven cure. Typical pot life is roughly an hour at around 20°C: warmer temps shorten it. If you’re still spraying as it thickens, you can lay down a skin that traps solvent, which later prints as micro‑cracks or crazing. Likewise, stacking coats without proper flash, or force‑drying too hot too soon, can create internal stress.
Film Build, Temperature And Mechanical Stress
Over‑application is a classic culprit. If you pile it on to “armour‑plate” thickness, the outer skin may cure faster than the inner film. As solvents leave and the film shrinks, tensile stress builds and you can see cracking, especially in corners and on flexible panels. Very low application temperatures slow solvent release: very high temperatures accelerate skinning. Add heavy mechanical flex (e.g., a plastic bumper being bent) and even a tough urethane can fracture.
How To Prevent Cracking
Proper Prep, Primers And Substrate Choice
• Clean methodically: degreaser first, then abrade, then degrease again. Don’t skip the second clean, prep contamination is the silent killer.
• Abrade for a uniform key: typically P80–P180 depending on substrate and desired texture. Feather any existing coatings soundly.
• Prime smartly: use a quality 2K epoxy or urethane primer on bare metals and fibreglass: use adhesion promoter on suitable plastics: check compatibility data if you’re going over unknown paint. Allow primers to fully cure and de‑gloss before RAPTOR.
• Respect substrate limits: very thin panels or highly flexible plastics may need lighter texture, lower build and proven adhesion promoters, or avoid altogether.
Correct Mixing, Gun Setup And Flash Times
• Mix exactly to the manufacturer’s ratio (commonly 3:1 with hardener). Shake/stir thoroughly. If allowed, reduce modestly (up to about 10%) for smoother flow or colder conditions, don’t guess: check the TDS.
• Pot life: plan batches you can spray within the recommended window. If it’s gelling, bin it.
• Gun setup: with a Schutz gun, set pressure per spec and test pattern on a card: with HVLP, a 1.7–2.0 mm tip is typical. Aim for consistent texture, not blobs.
• Flash between coats: allow the stated flash (often 60–90 minutes at 20°C) so solvents escape. Rushing stacks solvent: waiting too long can reduce intercoat adhesion, stay within the window.
Target Film Thickness, Curing And Early Care
• Build to a sensible total dry film thickness, think robust, not brick wall. Many pros target roughly 250–500 microns total depending on use.
• Temperature: apply around 15–30°C with decent airflow (dust‑free). Avoid cold, damp garages that slow solvent release.
• Cure time: handle after initial set, but avoid heavy loading for several days: full cure typically takes 3–7 days depending on conditions. Don’t strap down loads or flex panels on day one.
• UV and colour: if long‑term colour retention is critical, consider a compatible UV‑stable topcoat or choose lighter tints that hide fade better.
Troubleshooting And Fixes If It Cracks
Identify The Cause Before Repair
Don’t sand blindly. First, work out why it failed:
• Check thickness with a gauge if you have one, was it overbuilt?
• Review your process: mix ratio, pot life, flash times, booth temperature.
• Inspect what’s underneath: brittle primer? Uncured paint? Plastic without promoter?
• Perform a simple cross‑hatch adhesion test near the damage to gauge bonding.
Repair Options: Feather, Recoat Or Strip
• Localised cracks with otherwise sound adhesion: sand back past the cracks (feather to stable edges), key surrounding area, clean, and re‑apply lighter coats with correct flash.
• Widespread micro‑cracking or solvent‑trap crazing: you’ll often need to take it down further to a sound base, allow any trapped solvents to flash off, then rebuild with thinner coats.
• Delamination or incompatible underlayers: strip to a stable substrate, re‑prime with a compatible 2K epoxy/urethane, and recoat. Trying to bridge over a failing layer is a short‑term fix at best.
Blend carefully to hide the patch, matching texture is as important as colour with RAPTOR.
Real-World Durability And Expectations
Typical Outcomes Across 4×4, Marine And Utility
• 4×4/off‑road: RAPTOR stands up well to brush, gravel rash and boot scuffs. You’ll see chips on sharp rock impacts before you see cracking. Panels that flex heavily (plastic arch flares) demand adhesion promoter and sensible film build.
• Marine: good resistance to salt and freshwater, and the texture offers grip. UV exposure is harsher on decks and gunwales: expect gradual colour fade. Cracking is rare unless the substrate is moving (thin GRP panels) or prep was rushed.
• Utility/machinery/trailers: repeated loading, impact and chemicals are its home turf. Corners and edges benefit from extra attention in prep and slightly lighter build to avoid stress lines.
Maintenance That Extends Service Life
• Wash with mild pH‑neutral shampoo: avoid strong solvents and harsh degreasers.
• Rinse salt and winter road grime promptly.
• Inspect edges, bolt holes and high‑wear zones quarterly: touch in chips before water creeps under.
• Consider a periodic UV protectant compatible with polyurethane if appearance matters.
Treat it like a tough tool, not indestructible armour, and it’ll look good for years.