The versatile chemistry for electronic assemblies, filter applications and more...

SONDERHOFF FERMADUR are the two-component polyurethane systems for the manufacture of hard- to gel-like potting compounds.

They are directly applied to the part with the aid of SONDERHOFF mixing and dosing systems with FIP (Formed-In-Place) technology and cure there under room temperature.

Chemical constituents

The systems consist of a resin basis (A-component) and a hardener (B-component), which are mixed with each other in a predetermined mixing ratio. After suitable processing a bubble-free potting compound is formed in a few minutes.

The systems consist of a resin basis (A-component) and a hardener (B-component), which are mixed with each other in a predetermined mixing ratio. After suitable processing a bubble-free potting compound is formed in a few minutes.

The function of the potting compound is determined by the application. It can range from surface coating to protect against environmental effects, to encapsulating electronic components or bonding components. The flowability, reactivity, degree of hardness and color of the material formulations can be adjusted as required.

Henkel can draw on the variety of more than 500 application-specific formulations of the SONDERHOFF FERMADUR product family.

Your product is important to us – we will be happy to advise you!

Appearance Black or grey, other colours upon request (including transparent)
Hardness Covering the entire Shore A range up to 80 Shore D, also gel-like
Density From 0,8 g/cm³ to 1.7 g/cm³
Reacton time Adjustable from 60 s to 90 min
Flame retardant Up to UL-94 V-0 possible, even with 2 mm coating thickness
Other properties
E.g., light-fast, good thermal conductivity, can be used for rotation molding, dissipates static, hydrophobic, also available as a syntactic foam, with multilevel flow behavior, abrasion
resistant, greater adhesion
FERMADUR systems are processed using mixing and dosing machines for two components. The recommended processing temperature is 23 °C ± 5 °C at a relative humidity between 40 and 70 %.


Potting systems in difficult conditions

The SONDERHOFF FERMADUR systems are, with their many different characteristics, also available for use in very difficult surroundings, from outdoor or underwater uses to flame-protected applications for lighting in tunnels, or from uses requiring ATEX protection in explosion risk zones right up to optical potting, with good heat dissipation qualities for the high temperatures produced by high-power LED light technologies.


Swimming pool lighting

Depending on the complete construction, part and potting can reach impermeability classes to IP68 with SONDERHOFF FERMADUR, meaning that e.g. swimming pool lighting is possible.

Tunnel lighting

For tunnel lighting flame-retardant SONDERHOFF FERMADUR products can be created to meet UL94 V-0 testing standards.

EX protected lighting

For explosion-protected lighting elements, e.g. for emergency lighting in hazardous surroundings underground, our SONDERHOFF FERMADUR potting systems are formulated to withstand ATEX system testing in accordance with ATEX Directive 2016/34/EC.

Sealing of LEDs

The transparent polyurethane-based SONDERHOFF FERMADUR potting products, e.g. for the sealing of LEDs, are protected from UV-radiation by the use of aliphatic isocyanates and are temperature-stable to 130°C.


Broad potting spectrum covers very different requirements


The function of the SONDERHOFF FERMADUR potting system is determined by its application and can range from part protection against environmental influences through the sealing of electrical assemblies to the gluing of components such as the filter systems used in industry and the home.

Component sealing with SONDERHOFF FERMADUR potting protects parts from infiltration of damp, dust, foreign bodies, water and so on. The chemical properties of the material recipe can be varied so that the potting mass can be perfectly adapted to the task placed on it.

SONDERHOFF FERMADUR potting also can be used to join electronics together and for interference protection and electrical insulation of cables and plugs. Potting increases the mechanical stability and dielectric strength of the electronic parts, their vibration and shock resistance.

Potting with SONDERHOFF FERMADUR products impedes detachments or the opening of crevices at the edge of the potting mass because of dramatic temperature differences or vibrations, so that damp or aggressive materials cannot penetrate the part and adversely affect its functionality or even destroy it.

According to their conditions of use, SONDERHOFF FERMADUR potting systems can be adapted widely for their ease of flow, reactivity, hardness grade and colour.

SONDERHOFF FERMADUR potting possesses a very high tear resistance and flexural strength, so that components can still be used under extreme environmental conditions.


The SONDERHOFF FERMADUR potting systems offer a wide range of properties for different applications and requirements, from potting for lighting and sensitive electronic components, through the bonding of filter packets and viewing windows in control cabinets to the coating of conveyor belts and transparent component surfaces.

Applications* Viscosity (A)
Shore 00
Other properties*
A-113-5-VP1 Potting compound for instrument and
connector plugs
1.000 A50 1,15 Flexible, levels very well, low shrinkage,
low surface tension
A-112-VP2 Filter gel 200 A30 1,00 Soft, gel-like, permanently sticky
A-134-10-VP6 Potting compound for sensors, circuit boards, electric switches and sensor elements approx. 1.800 A65 1,35 Flexible standard systems for electronics in the
automotive industry, listed in various OEMs, good adherence
A-134-15-VP2 Potting compound for sensors, circuit boards, electric switches and sensor elements 8.000 D40 1,40 Hight temperature resistant, aliphatic potting compound, UV stable
A-125-6 Potting compound for plugs 1.200 A70 1,10 Flexible potting compound, low shrinkage, low surface tension
A-203-3-VP Potting compound for transistors 1.200 A70 1,20 Flexible, for sensitive electronic applications,
low shrinkage, low surface tension
A-690 UL1 Potting compound for transducers 6.000 D80 1,60 UL94 V-0 listing at 1.5 mm, hard, good thermal conductivity
A-66D05-3 Binder natural stone 3.100 D45 1,10 Aliphatic, UV and weather resistant, tough elastic
A-117-37 Potting compound for transformers,
voltage transformers, capacitors, control units
23.000 D75 1,70 Hard, thermal conductivity 0.9 W/mK, conforms to UL94 V-0 at 3 mm
A-111-1-VP Potting compound for sensors and
circuit boards
300 gel-like
- A60
1,25 Transparent, soft to gel-like, for sensitive
electronic applications
A-180-1-VP1 Potting compound for light diodes 1.000 A70 1,10 Transparent, UV stable, tough-hard, temperature
stable up to +165 °C, high chemical resistance
A-173-3-VP1 Potting compound for cable sheathing or molded parts for cable routing approx. 1.000 A50 0,80 Slightly foaming, flexible, high longitudinal water
tightness achievable
A-120-1-VP1 Adhesive for panes in enclosures 200.000 D30 1,30 Tough-hard, good adherence on various
substrates, high mechanical stability,
can be used as a glue, highly thixotropic
A-25D45-01-R Rotation molding compound 50.000 D50 0,40 Hard, foamed potting, thixotropic
A-80DC8-1-CON Rotation molding compound for ferrules 250.000 D80 1,40 Non-drip, high stability and chemical resistances,
static dissipative potting compound
A-640-VP6 Coating for conveyor belts 23.000 A75 1,15 Flexible, particularly tear resistant
A-196-4-F Potting compound for filter end caps and adhesive for filter cartridges 1.000 D40 1,15 Tough-hard, good adherence to various substrates, two-step flow behavior available

* The description of the possible fields of use of our products as well as the technical data and values only have a general character and do not mean that a certain product can be used under all conditions in the respective field of use. In this respect, the stated field of use is not a binding specification or usage provision. Due to the great number of environment variables and their influences (e.g. temperature, test specimens, size, interaction with substrates, influence of machines, or the like) you as our customer must check whether the product is suitable for your specific field of use. We will be pleased to assist and advise you in this respect.


Good reasons for using SONDERHOFF FERMADUR


  • … can be used at a constant temperature up to +180°C, for special types up to +250°C
    and temporary up to +350°C.
  • … keeps the greatest possible flexibility even down to -60°C.
  • … is closed-cell and therefore nearly do not absorb water.
  • … is highly resistant to many chemicals.
  • … is hydrolysis stable and therefore suitable for use in tropical or damp environments.
  • … is tack-free in 2– 60 minutes, depending on the thermal conditions. A furnace can significantly
    shorten the reaction time, but it is not always necessary.
  • … is processed using a mixing and dosing machine for two components and can be adapted flexibly
    and quickly to other parts for sealing application at any time.
  • … develops a cross-linked structure which is extremely resistant to environmental effects
    such as humidity, dust and temperature.
  • … has an exceptional long-term behavior and almost 100% resetting ability, even after many years
    of continual use.
  • … is in some cases also suitable for direct contact with food.