Urethanes Conformal coating 2A64
Model No: 2A64

HumiSeal® 2A64 is a two component polyurethane conformal coating supplied as Parts A and B, suitable for general printed circuit board applications. HumiSeal® 2A64 is characterized by high solids and low viscosity for ease of application and processing, and it fluorescence under UV light for inspection purposes.

 Product Enquiry

HumiSeal® 2A64 conformal coating is:

  • Urethane chemistry
  • chemically resistant
  • two component
  • used in combination with Thinner 64


HumiSeal® 2A64 conformal coating has:

  • excellent moisture and environmental protection for printed circuit assemblies
  • fluorescence under UV light for ease of inspection
  • MIL-I-46058C qualified
  • IPC-CC-830 compliant
  • RoHS Directive 2015/863/EU.


Application of HumiSeal® 2A64 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. 

Mixing ratio of Part A to Part B is 1:1 by volume. Prior to application, HumiSeal® 2A64 Parts A and B should be thoroughly mixed until a homogenous blend is achieved. Vigorous mixing is not recommended. The mixed coating should be allowed to settle for 30 minutes prior to use so that any air bubbles formed during blending can escape.


Properties of Mixed HumiSeal® 2A64

Density, per ASTM D1475

1.07 ± 0.03 g/cm3

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

55 ± 5 %

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

130 ± 50 centipoise


501 grams/litre

Recommended Coating Thickness

25 – 75 microns

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

15 minutes

Optional Curing Conditions to Reach Optimum Properties

3 hrs @ 76°C

Recommended Thinner

HumiSeal® Thinner 64

Recommended Stripper

HumiSeal® Stripper 1072

Pot Life at Room Temperature

8 hours

Shelf Life at Room Temperature, DOM

12 months

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

-65°C to 125°C

Coefficient of Thermal Expansion – TMA

82 ppm/°C Below Tg
255 ppm/°C Above Tg

Glass Transition Temperature – DSC


Modulus – DMA

4101 MPa @ -40ºC
2777 MPa @ 25ºC
2 MPa @ 80ºC

Flammability, per MIL-I-46058C


Dielectric Withstand Voltage, per MIL-I-46058C

>1500 volts

Dielectric Breakdown Voltage, per ASTM D149

3500 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

4.5 x 1014  ohms (450TΩ)

Moisture Insulation Resistance, per MIL-I-46058C

4.8 x 1010 ohms (48GΩ)

Fungus Resistance, per ASTM G21