Choosing the Right Paint for Your Tank: What to Remember

All tanks fabricated by Fuelchief in New Zealand, including SuperVault, Praxis, Vanguard, and Pyrotector, are supplied fully painted. Factory-applied paint protects long-term durability and keeps the manufacturer's warranty intact.

Our welded range is painted to C5-I as standard, using an industrial-grade coating from Hempel (an ISO 12944 supplier) for durable, high-performance protection. A C5-M marine-grade option is also available for coastal and high-salinity environments, at an additional cost.

ISO 12944 defines five atmospheric corrosivity categories, based on how aggressive the environment is toward steel:

Fuelchief's welded range is painted to C5-I as standard, which covers most industrial applications. C5-M is available for tanks in marine or high-salinity coastal environments.

When specifying paint for a custom welded tank, four factors drive the decision:

1. Environment

The conditions the tank will operate in determine everything else.

Key factors include:

• Humidity
• Temperature range
• UV exposure
• Chemical exposure
• Risk of mechanical damage from impact or abrasion

For buried tanks, ground conditions matter too:

• Soil porosity
• Moisture
• pH
• Exposure to bacteria and micro-organisms.

For submerged applications, the chemical composition of the water is significant. These factors together determine the paint type, total coating thickness, surface preparation required, and re-coating intervals.

2. Type of Protected Surface

The base material affects the choices that follow. Steel, hot-dip galvanised steel, spray-metallised steel, aluminium, and stainless steel each call for different surface preparation, primer selection, and coating thickness.

3. Durability Required

ISO 12944 defines three durability ranges for how long a coating lasts before it needs maintenance:

Fuelchief's combined coating systems exceed the "high" category, delivering over 35 years of protection across our tank range.

4.Application Planning

Paint needs to be applied at the right point in the build process, accounting for prefabrication, on-site assembly, and completed structures. Surface preparation and drying or curing times both depend on temperature and humidity. If a tank moves between a controlled workshop environment and an on-site setting during construction, re-coating intervals need to be factored in too.

For our fabricated tank range, surface preparation and application follow a strict process.

All surfaces are cleaned, dried, and checked for contamination, assessed against ISO 8504:2000, with oil or grease removed per SSPC-SP1 solvent cleaning standards. Surfaces are then abrasive blast cleaned to Sa2.5 (ISO 8501-1:1988) or SSPC-SP6, a near-white metal finish that removes almost all visible contamination. If oxidation occurs between blasting and painting, the surface gets reblasted, and any defects revealed during blasting are ground, filled, or treated as needed.

Stripe coats are applied to welds, lap joints, plate edges, corners, and any other areas where standard spray application could leave a thin coating.

This process delivers over 35 years of corrosion protection across Fuelchief's tank range, and every tank fabricated in New Zealand is audited and backed by a paint manufacturer's warranty.