H.B. Fuller 1581

H.B. Fuller 1581 is a one-component, alcohol-cured RTV silicone sealant. A non-sag material with excellent heat resistance for use in industrial and electronics applications. 1581 has very good adhesion to a wide range of unprimed substrates. High performance with fast and excellent adhesion to glass, aluminum alloys, etc. It can be used for a variety of electronics bonding, encapsulation, and sealing applications. This material is certified by UL to pass HB flame rating testing. This material performs at temperatures ranging from -55°C to 210°C.

Product Type1K (1 component) Sealant, Encapsulant

Application AreaAppliances, Batteries, Battery Packs, Blades, Edge Gluing, Electric Vehicle (EV), Electrical Boxes, Electronic Components, Encapsulant, Energy Storage, Frame Sealing, Glass Surface, HVAC Applications, Ingot Bonding, Junction Boxes, Lithium-Ion Battery, Module Installation, Rail Bonding, Solar Cell, Turbines

Compatible Substrates & SurfacesGlass

Chemical FamilySilicones, Siloxanes

FeaturesExcellent Performance, Good Sagging Resistance, Good Weather Stability, Heat Resistance, UV Resistant

Technical Data Sheet

Enhanced TDS

Identification & Functionality

Chemical Family

Features & Benefits

Labeling Claims

Applications & Uses

Compatible Substrates & Surfaces
Cure Method
Curing Conditions

Cure speed will vary with temperature, relative humidity, depth of material and presence of moisture. Some applications may require special surface preparation. At 21 - 25°C, 45 - 55% relative humidity, typical cure depth is 2mm in 24 hours. Requires more time to cure in colder or lower humidity conditions.

General Instructions
  • For best performance bond surfaces should be clean, dry and free of any contaminants and oils.
  • Apply a continuous and even bead of silicone to one surface.
  • Assemble parts immediately. Remove excess material at once.


Electrical Properties
ValueUnitsTest Method / Conditions
Volume Resistivity3.0 x 10¹⁵Ω.cmIEC60093, GB/T1692
Breakdown Voltage20.0kV/mmIEC 60243-1, GB/T1695
Cured Properties
ValueUnitsTest Method / Conditions
Elongation at Break (21 - 25°C, 50% RH)380.0%
Lap Joint Shear Strength (at 21 - 25°C, 50% RH, Aluminum)1.2MPa
Hardness (at 21 - 25°C, 50%Rh)37.0
Tensile Strength (at 21 - 25°C, 50% +RH)2.1MPa
Thermal Service Range- 54 - 210°C
Damp Heat Aging Test Properties
ValueUnitsTest Method / Conditions
Tensile Strength (at 21 - 25°C, 50% +RH)1.3MPaISO37, GB/528
Elongation at Break (at 21 - 25°C, 50% RH)300.0%ISO37, GB/528
Uncured Properties
ValueUnitsTest Method / Conditions
Tack Free Time15.0min
Full Cure Time (21 - 25°C, 45 - 55% RH, min. 2mm)24.0h

Regulatory & Compliance

Certifications & Compliance

Packaging & Availability

Regional Availability
  • Africa
  • Asia Pacific (Excluding Russia)
  • Europe (Excluding Russia)
  • India
  • Latin America
  • Middle East
  • North America
Packaging Information

310ml Cartridge

Storage & Handling

Storage Condition

Product shall be ideally store in a cool, dry area in unopened containers. Material should be stored at a temperature of 8 - 25°C. Optimal storage is at the lower half of this temperature. Do not return unused material back into the container.