Acrylics Conformal coating 1B31
Model No: 1B31

HumiSeal® 1B31 is a fast drying, single component, acrylic conformal coating that provides excellent moisture and environmental protection for printed circuit assemblies. HumiSeal® 1B31 demonstrates excellent flexibility, fluoresces under UV light for ease of inspection and is easily repaired.

 Product Enquiry

HumiSeal® 1B31 conformal coating is:

  • an acrylic chemistry
  • fast drying
  • single component


HumiSeal®1B31 conformal coating has:

  • excellent moisture and environmental protection for printed circuit assemblies
  • excellent flexibility
  • fluorescence under UV light for ease of inspection
  • rework ability with ease
  • MIL-I-46058C qualification
  • IPC-CC-830 compliance
  • RoHS Directive 2002/95/EC compliance


Application of HumiSeal® 1B31 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. 


Product Specification

Density, per ASTM D1475

0.91 ± 0.02 g/cm3

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

35 ± 3 %

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

200 ± 15 centipoise


592 grams/liter

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

10 minutes

Recommended Coating Thickness

25 – 75 microns

Recommended Curing Conditions

24 hrs @ RT or 30 min @ 76°C

Time Required to Reach Optimum Properties

7 days

Recommended Thinner (dipping & brushing)

HumiSeal Thinner 503

Recommended Thinner (spraying)

HumiSeal Thinner 521, 521EU

Recommended Stripper

Stripper 1080, 1080EU

Shelf Life at Room Temperature, DOM

24 months

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

-65°C to 125°C

Coefficient of Thermal Expansion – TMA

170 ppm/°C below Tg340 ppm/°C above Tg

Glass Transition Temperature – DSC


Modulus – DMA

2000 MPa @ -40°C1050 MPa @ 20°C8.5 MPa @ 60°C

Flammability, per MIL-I-46058C


Dielectric Withstand Voltage, per MIL-I-46058C

>1500 volts

Dielectric Breakdown Voltage, per ASTM D149

7500 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

8.0 x 1014 ohms (800TΩ)

Moisture Insulation Resistance, per MIL-I-46058C

6.0 x 1010 ohms (60GΩ)

Fungus Resistance, per ASTM G21