Charge Air Cooler Fin Material

Main fin materials for marine CAC

1. Aluminum fin (most common OEM standard)

Alloy: 1050 / 1060 pure aluminium, thickness 0.12‑0.20 mm

✅ Pros: Highest thermal conductivity, low cost, easy stamping for dense fin pattern, light weight

❌ Cons: Vulnerable to acid condensate corrosion under slow‑steaming / low‑load operation; salt‑fog corrosion in engine room; galvanic corrosion risk when mated directly to copper‑nickel tubes if condensate forms electrolyteGovInfo.

👉 Solution: Epoxy / E‑coated aluminium fins. Thin protective coating against acid & salt mist; widely used for 2‑stroke main engine CAC to extend service life

👉 Typical use: Standard ocean‑going merchant vessels, new‑build OEM units.

 

2. Copper fin (tinned‑copper is popular marine grade)

‑ Thickness 0.15‑0.22 mm; often tin‑plated copper fin

✅ Pros: Very good thermal conductivity; far better acid‑condensate resistance than bare aluminium; good mechanical strength, less easy to bend during cleaning.

❌ Cons: Higher cost, heavier.

👉 Typical use: Retrofit upgrade, vessels operating frequently at low‑load / slow‑steaming; many European aftermarket CAC suppliers select tinned‑copper fins.

 

 

3. Stainless‑steel fin (304 / 316L)

‑ Thickness 0.10‑0.15 mm

✅ Pros: Excellent resistance to acid condensate, sulphur, salt‑mist, high temperature; mechanically tough, resistant to jet‑wash damage.

❌ Cons: Poor thermal conductivity, so requires larger fin area; higher air‑side pressure drop; higher material cost.

👉 Typical use: Harsh condition: heavy‑fuel high‑sulphur fuel ships, offshore, fishing vessels; rarely for standard large 2‑stroke main engine due to thermal penalty.

 

4. Cu‑Ni fin (copper‑nickel 90/10)

✅ Pros: Outstanding corrosion resistance, good compatibility with Cu‑Ni tubes, minimal galvanic risk.

❌ Cons: Very expensive, limited supply for thin fin strip.

👉 Typical use: Special naval / high‑end offshore projects only, not standard commercial merchant ships.

 

Fin coating options (critical upgrade)

E‑coating / Epoxy coating: For aluminium fins. Uniform thin polymer layer, resist sulphuric condensate and salt spray; maintain heat‑transfer performance; most widely adopted upgrade for slow‑steaming vessels.

Tin‑plating: Applied on copper fins; improve anti‑corrosion, reduce soot sticking tendency.

Note: Heavy paint coating is not allowed; thick coating will insulate and reduce heat transfer.