Summary: Tank linings must resist the stored medium, manage static/conductivity and meet confined-space safety. Choose the resin backbone by medium, then build primer/topcoat and film thickness. Below ~85% RH cure and pinholes must be controlled.
Mechanism
Water/neutral media suit epoxy; strong acids need vinyl ester or novolac epoxy; fuel/solvent tanks use solvent-free epoxy; flammable contents require conductive (anti-static) linings to dissipate static charge.
Key data
- Medium sets the resin: pH 2-12 neutral ranges use bisphenol-A epoxy; strong acids switch to vinyl ester.
- Solvent-free epoxy approaches 100% solids and very low VOC, suitable for food / potable-water tanks.
- Conductive linings often target a surface resistance around 10^5-10^8 ohm to bleed static without fast corrosion.
- Internal builds are multi-coat with controlled recoat intervals and pinhole spark testing.
- Confined-space work needs ventilation and explosion/oxygen monitoring, stricter with solventborne.
Selection by medium
| Medium | System | Note |
|---|---|---|
| Water / neutral | Bisphenol-A epoxy | General; needs good surface prep |
| Strong acid / chemical | Vinyl ester / novolac | High acid and solvent resistance |
Defects & fixes
- Blistering: substrate moisture or medium permeation — control RH, build barrier, spark-test.
- Static build-up: plain insulating coat on flammable media — switch to conductive lining.
- Weld seams miss coverage: grind and stripe-coat edges before full application.
FAQ
Can solventborne be used in potable tanks?
Prefer solvent-free/waterborne food-grade epoxy meeting hygiene testing; solventborne is constrained by VOC and residue.
How to know it needs anti-static?
Store of flammable products/solvents should use conductive linings to avoid static discharge ignition.
How to find pinholes?
After cure, spark-test at standard voltage; pinholes discharge and are re-coated.
Ref: GB 50050-type tank anti-corrosion design and ISO 12944 grading; potable-water coating hygiene evaluation (public standards).
Kexin New Materials (Guangdong) Co., Ltd. · 2026-09-18