Skip to main content

Si 57 EL

Epoxy-Phenolic-based Heat Cured Hydrophobic Lining for Strong Alkalis to Weak Acidic Media. For the Coating of Finned (Air) Coolers. High Gloss, Dark Brown Finish

SÄKAPHEN Si 57 EL is a high-quality hydrophobic single-component epoxy-phenolic thermosetting heat cured lining specifically formulated for the coating of finned air coolers as used in HVAC and HVAC-R equipment. The lining is self-priming and formulated for direct to metal application. The coating can be applied on coolers being operated either onshore and or offshore in an agressive marine environment.  In marine environment, the polyurethane topcoat is recommended.

Si 57 EL is chemically resistant to fumes, mist (also in droplets) of strong alkaline to weak acidic media, salt solutions, greases, oils and gases and all types of cooling water (including brackish, river, sea water and deionized water) and when used in conjunction with a polyurethane topcoat offers UV protection. Si 57 EL is also resistant to temperature fluctuations.

The lining film surface is hard elastic with outstanding hydrophobic properties, preventing caking, fouling and incrustation. Once polymerized, the lining is fully machinable with a formaldehyde concentration level of less than 0.1%.

Optimized for coating of Finned Air Coolers as used in HVAC and HVAC-R equipment, due to extremely low viscosity.

Product nameUnitSÄKAPHEN® Si 57® EL  
 Properties-Heat Cured Duroplast Coating  
 Resin base-Phenolic epoxy resin blend  
 Field of Application-Optimized for the application on finned air coolers. Due a particular low viscosity finned air coolers with a fin pitch from 1,5mm upwards can be protected.  
 Cure Mechanism-Heat cured  
 Quantity of components-1  
 Color-Dark Brown  
 General chemical resistance (All resistances have to be inquired separately!)-Resistant to fumes and mist also in droplets of strong alkaline to weak acidic media, all type of cooling waters brackish, river and sea water as well as deionized water, salt solutions, greases, oils, solvents, gases.  
 pH RangepH3 - 14  
 Wet Film Thickness per layerµm50  
 Total dry film thicknessµm30-80  
 Coverageapprox. kg/m²/DFT0,4 kg / m² / 80µm  
 Surface PreparationSaSA2 ½ - SA 3  
 Surface Profileµm40 - 60 µm*  
 Temperature resistance dry (dry air oven)°C-20°C to +180°C/200°C  
 Temperature resistance wet (water)°C-20°C to +180°C/200°C  
 Resistance to water vapor diffusion°C≤ ∆T 30°C  
 Overcoating Waiting Timehours/23°Cno limitations  
 Chemical Curingdaysafter final bake  
 Linear Thermal Expansionµm(VDE 0304): 44*10-6 mm/mm°C  
 Pore testingVolts67,5  
 Pendulum hardness acc. to König6° sec200  
 Shore D HardnessShore D94  
 Adhesion TestN/mm² [MPa]>30  
 Salt spray testhours1400  
 Impact Strengthmm (1 kg)> 1000  
 Surface smoothness (Ra)µm
Ø 3 readings
 Surface tensionmN/m<28  
 Taber Abrasion resistance, CS17 wheel, 1kgmg/1000 r.27  
 Crosscutclass0 (DIN EN ISO 2409)  
 Heat conductivity
Ø 12,7x2,0mm on C-Steel with 67,37 w/mK
 Comments *Surface profile on the frame,
fins remain untreated.

Thin film linings based on epoxy-phenol hybrids have a surface smoothness of less than 1/1000 mm. Simultaneously, the surface tension is less than 28 mN/m. Thus preventing incrustation and increasing flow.

SÄKAPHEN Heat Cured Linings and Coatings

High-End Corrosion Protection and Carbon Footprint Reduction

Feel free to contact us for technical advice.

For any specific chemical resistances, fields of use, technical questions or other lining and coating queries, please feel free to contact us for technical advice.

Tel.: +49 20439470 or Email: info[at]

SÄKAPHEN is happy to support!


* Mandatory fields