Silicones 1C48
Model No: 1C48

HumiSeal® 1C48 is a moisture curing, high build, VOC-free silicone conformal coating which provides excellent moisture and environmental protection for printed circuit assemblies. HumiSeal® 1C48 is solvent free. The coating demonstrates outstanding flexibility, fluorescence under UV light for ease of inspection and can be repaired. HumiSeal® 1C48 can be cured at room or at elevated temperatures.

 Product Enquiry

HumiSeal® 1C48 conformal coating is:

  • silicone based
  • fluoresces under UV light
  • room temperature, moisture cure
  • single component
  • high solids


HumiSeal® 1C48 conformal coating has:

  • no VOCs or solvent
  • low toxicity
  • excellent environmental resistance and moisture resistance
  • RoHS Directive 2015/863/EU compliant


Application of HumiSeal® 1C48 Silicone Conformal Coating

Conformal coatings can be successfully applied to substrates that have been cleaned prior to coating and also to substrates assembled with low residue “no clean” materials. Users should perform adequate testing to confirm compatibility between the conformal coating and their particular assembly materials, process conditions and cleanliness level.

1C49 is designed for application without additional thinning. Solvents or other thinners should not be mixed with 1C48. 1C48 may be applied by spray, brushing, flow coating or dipping. The time required to reach a tack-free state is dependent on ambient conditions such as temperature and relative humidity. The processing guidelines contained in this document were obtained with an ambient relative humidity of 50%.


Product Specification

Density, per ASTM D1475

1.01 ± 0.03 g/cm³

Min. Solids Content, % by weight per Fed-Std-141, Meth. 4044


Viscosity, per Fed-Std-141, Meth. 4287

270 ± 50 centipoise


0 grams/litre

Recommended Coating Thickness

50 – 200 microns

Drying Time to Handle per Fed-Std-141, Meth. 4061


5 min (100 μm, 50% RH at 21 ºC)
8 min (200 μm, 50% R.H. at 21 ºC)
1.5 min (100 μm, 8% R.H. at 60 ºC)
4 min (200 μm, 8% R.H. at 60 ºC)

Recommended Curing Conditions

24 hrs @ RT or 20 min @ 76°C*

Time required to Reach Optimum Properties

7 days

Recommended Stripper

HumiSeal Stripper 1091

Shelf Life at Room Temperature, DOM

12 months

Thermal Shock, 50 cycles per MIL-I-46058C

-65°C to 200°C

Coefficient of Thermal Expansion – TMA

367 ppm /ºC

Glass Transition Temperature – DSC

< -65°C

Storage Modulus – DMA

408 MPa @ -40ºC
1.6 MPa @ 25ºC
1.4 MPa @ 80ºC

Tensile, per ASTM D412

30-50 psi

Elongation, per ASTM D412

80-120 %

Build per Dip, per ASTM D823

5 mils

Flammability, per UL94


Dielectric Withstand Voltage, per MIL-I-46058C

>1500 volts

Dielectric Breakdown Voltage, per ASTM D149

7000 volts

Dielectric Constant, at 1MHz and 25°C per ASTM D150-98


Dissipation Factor, at 1MHz and 25°C per ASTM D150-98


Insulation Resistance, per MIL-I-46058C

5.0 x 1014 ohms (500TΩ)

Moisture Insulation Resistance, per MIL-I-46058C

1.0 x 1010 ohms (10GΩ)

Fungus Resistance, per ASTM G21


* Place an open pan of water in the oven during curing