Waterborne Polysiloxane (Sol-Gel) Coil Coating
Key specifications
| Property | Value | Standard |
|---|---|---|
| Dry film thickness | 5–15 μm (0.2–0.6 mil) | Microscopy / eddy-current gauge |
| Heat-transfer efficiency loss | ≤ 1.8 % | GB/T 8446.2 |
| Neutral salt spray | ≥ 2,000 h, no red rust | GB/T 10125-2021 |
| Acetic acid salt spray | ≥ 800 h | GB/T 10125-2021 |
| Copper-accelerated salt spray | ≥ 350 h | GB/T 10125-2021 |
| Adhesion (cross-cut) | Grade 0 | GB/T 9286 |
| Pencil hardness | ≥ 2H | GB/T 6739 |
| Thermal cycling | −60 °C to 150 °C × 100 cycles, no cracking | GB/T 2423.4 |
| Chemical resistance | 2% H₂SO₄ and 2% NaOH, 48 h immersion no change | |
| Cure | Thermal (recommended) or ambient moisture-cure | |
| Application | Dip (recommended), low-pressure spray, roller | |
| Substrates | Cu, Al, Al alloys, stainless steel, galvanised steel |
Laboratory values from the coating data sheet.
Suitable for
- Suitable: New Cu-Al and microchannel coils coated before shipment
- Suitable: OEM dip lines with thermal cure
- Suitable: Coastal and tropical sites rated C3 to C5
- Suitable: High-density fins where heat transfer must be preserved
Not suitable for
- Not suitable: Wastewater, H₂S or chemical plant exposure — use PG-C
- Not suitable: Heavily corroded coils already in service
- Not suitable: Direct marine spray rated CX without a topcoat
- Not suitable: Units that cannot be dipped or sprayed evenly on site
Matches these environments
Compare with other systems
| System | Film thickness | Cure | Best for |
|---|---|---|---|
| PG-S1This system Waterborne polysiloxane (sol-gel) | 5–15 μm | Thermal or ambient | New coils before shipment, OEM dip lines |
| PG-S2 Polysiloxane-urethane clearcoat | 5–10 μm | 160 °C / 60 min | Aluminium radiators, bakeable heat exchangers |
| PG-W Waterborne two-component | 5–10 g/m² per side | 80 °C touch-dry | Coil lines, mild coastal and humid sites |
| PG-C Air-dry two-component, chemical-resistant | 20–40 μm | Ambient 72 h | Complete units, chemical and wastewater sites |
How PG-S1 is applied
Dip coating is the recommended method. Full immersion reaches the inner rows of the coil and the fin roots that spray cannot, and controlled drain-off keeps the film inside the 5–15 μm window.
Cure is the step that decides performance. Under-cured film loses adhesion and fails salt spray early, so the cure temperature and time are logged for every batch and adhesion is tested on panels cured alongside the coils.
Two-component option. Where a faster, harder cure is needed, PG-S1 is also supplied as a two-component version with a pot life of 2–4 hours after mixing. Mixing is done per shift and recorded in the batch report.
Related
- CoatingsNano Coatings for Heat Exchangers
- ServicePre-Shipment Coil Coating in China
- StandardsHow Coating Impact on Heat Transfer Is Tested
- ComparisonsThin-Film vs Thick-Film Coil Coatings
- GuidesDoes Coil Coating Reduce Heat Transfer?
- ServiceDip Coating for Finned Heat Exchangers
Also see
- StandardsMeasuring Dry Film Thickness on Fins
- ComparisonsAir-Dry vs Baked Coil Coatings
Can PG-S1 be applied without an oven?
Yes. It moisture-cures at ambient temperature. Thermal cure is recommended because it gives a harder film sooner and more consistent results.
Does it bridge between fins?
At 5–15 μm the film is thin enough for standard fin pitches. Every batch is checked for fin bridging during QC.
Can it be used on microchannel coils?
Yes. Aluminium and aluminium alloys are listed substrates. Dip application reaches the inner louvres.
How is it repaired on site?
Field repair kits use a compatible low-pressure spray or brush-on version for scratches and brazed joints.
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