362.1 Zinc systems (hot-dip/thermal)

Zinc undercoats shield steel in harsh sites. Duplex systems keep HVM bollard cores protected and reduce crash rated bollard base corrosion (334).

Hot-dip galvanizing forms a metallurgically bonded zinc-iron layer that provides barrier and sacrificial protection—ideal for carbon-steel cores and baseplates that face splash zones and de-icing salts. Thermal spray zinc (TSZ) is a good alternative where immersion tanks are impractical or where localized thickening is required on edges and welds. In coastal or high-sun environments, pair zinc with a UV-stable topcoat to limit chalking.

Remember that coatings don’t upgrade a rating: protection choices must not alter the as-tested product family geometry (415). Specify mask/vent points on base sockets to avoid zinc pooling and to respect sleeve fit tolerances (315). When the design includes drainage pits (334), extend zinc coverage down to the splash line and touch-up (see 362.8) after drilling/bolting.

362.2 Powder vs liquid paints

Powder gives robust finishes; liquid excels on-site repairs. Choose a system that preserves HVM bollard aesthetics and crash rated bollard warranty terms.

Powder coating offers high build, excellent chip resistance, and consistent color on factory lines. It’s efficient for sleeves and panels but needs controlled ovens and careful masking of threads and gland plates. Two-pack liquid polyurethane or polysiloxane systems are more forgiving for complex geometries and are easier to repair in the field with matched DFT and sheen.

For GCC climates, specify UV-stable binders and pigments with a documented gloss retention target. On bollard heads and high-wear rings, prioritize abrasion resistance over decorative effects. Coordinate color and reflectivity with Color & Aesthetic Finishes (366) and ensure consistent appearance across mixed arrays (fixed + automatic).

362.3 Polyurea & elastomers

Tough skins resist abrasion/impact. Use where an HVM bollard faces carts and trolleys; confirm elastomer doesn’t alter crash rated bollard geometry (421).

Spray-applied polyurea and elastomer jackets produce a thick, seamless shell that shrugs off scuffs and minor impacts. They’re helpful at mall frontages and service yards where trolleys, carts, or bikes scrape bollard heads. Control thickness so the rating-critical dependencies—effective diameter and head shape—remain within the as-tested envelope (421). Use color-stable topcoats or integrate a colored aliphatic layer where aesthetics matter (366).

Note compatibility: elastomers over fresh galvanizing require aged or pre-treated surfaces; over powder, confirm adhesion promoters. Where sleeves are used for architectural finishes, keep elastomers to the sleeve—not the core—to simplify future replacement (842).

362.4 Duplex systems

Galv + paint extends life. Control prep/DFT so the HVM bollard surface remains inspectable and the crash rated bollard sleeve fits (315).

A duplex coating (zinc + organic) extends time to first maintenance substantially via synergistic protection. Success hinges on surface preparation: sweep-blast the zinc to create a profile, remove white rust, and apply a compatible primer swiftly to avoid passivation.

Specify system DFT by zone—higher build at splash/impact areas and controlled build at sleeve interfaces. Record batch, cure, and DFT values into the Inspection & Test Plan (ITP) (714) so inspectors can track holds and witness points (918, 638). For UV/sand exposure, consider polysiloxane topcoats for gloss/colour retention (337).

362.5 Surface prep & blast grades

Specify Sa 2½/3 and profile. Good prep prevents premature failure on HVM bollard heads and at crash rated bollard plates.

Surface preparation determines coating life. For new steel, Sa 2½ is typically adequate; use Sa 3 for critical edges and head rings exposed to abrasion. Define anchor profile (e.g., 50–75 μm) matched to the primer system, and require stripe coats on edges and welds before full coats (see 362.7). For galvanized substrates, use sweep blasting (non-metallic media) to avoid cutting the zinc layer.

Seal cavities and pinholes, deburr torch cuts, and specify clean, dry, salt-free steel per test kits. Document prep photos in the ITP with hold/witness points aligned to coating application (716, 918). Tie prep grades to acceptance evidence in the Handover Pack Index (736).

362.6 DFT & QA checks

Record wet/dry film and holidays (714). QA evidence supports HVM bollard handover and crash rated bollard documentation (444).

Specify Dry Film Thickness (DFT) per layer and per zone, not just a total. Use calibrated combs and electronic gauges to log wet/dry film values, and conduct holiday (pin-hole) testing on high-build systems and elastomers. Include adhesion (cross-cut/pull-off) where repairs or overcoats are expected. Environmental records—steel temperature, dew point, RH—must be captured at each coat.

All readings and NCRs flow into the project’s evidence pack and evidence & documentation (444). Reference acceptance bands and rework criteria in the ITP (714) so the site team can close out coating items before SAT (638).

362.7 Edge/crevice protection

Stripe coats and seal edges. Protection stops creepage at HVM bollard caps and crash rated bollard anchor zones.

Edges and crevices fail first. Require stripe coats on all sharp edges, weld toes, and bolt holes; ease edges (2–3 mm radius) before coating to improve film hold. Seal joints at caps and head rings to block capillary moisture. Where hot-dip is used, manage meniscus edges to avoid thin paint films over ridges.

At baseplates and anchor interfaces, specify caulk/sealant details and inspect after torqueing. For removable sleeves, seal top lips to reduce ingress while keeping sleeves serviceable (842). In coastal sites, combine physical sealing with a robust duplex schedule to limit underfilm corrosion (363).

362.8 Repair procedures

Define repair kits and cure times. Fast fixes keep HVM bollard uptime high without harming the crash rated bollard sleeve.

Repairs are inevitable—codify them. Stock site repair kits (zinc-rich primer, two-pack topcoat, measured abrasives, wipes, gauges) and publish a one-page runbook with surface prep steps, overcoat windows, and cure times at typical UAE temperatures (337). For galvanized damage, use zinc-rich systems or TSZ per manufacturer guidance; for powder, use compatible liquid touch-ups and note sheen differences.

Record all repairs in the asset register (732) and maintenance plan (734). Where the damage suggests impact, trigger a post-incident inspection (735) before returning the lane to service.

362.9 Warranty conditions

Capture cleaning intervals and exclusions. Meeting terms preserves HVM bollard coverage and crash rated bollard claims.

Warranties usually require periodic washing (monthly in coastal/industrial zones), prompt repair of coating damage, and proof of maintenance. Clarify inclusions (UV/gloss retention) and exclusions (abrasion, chemical spills) and tie them to your lifecycle plan (842). Store batch certificates, color references, and cure logs with the O&M manual (733) and keep an escalation path for contested claims.

Finally, confirm that aesthetic finishes (366) layered over protective systems do not breach the manufacturer’s system build or invalidate guarantees. Note any owner cleaning policies and spares policy (854) regarding touch-up paints and sleeve replacements.

362 Coatings — FAQ