DELO-GUM Silicone Adhesives and Sealants
DELO-GUM adhesives and sealants are one-component, moisture-cured silicone products, used for fixing, sealing, potting, and encapsulating in applications where rigid cured adhesives would crack, delaminate, or transmit damaging mechanical stress to the assembly. The range covers standard industrial grades, high purity grades for sensitive electronic applications, and formulations maintaining sealing integrity at sub-zero temperatures.
What is a Silicone Adhesive?
Silicone adhesives are elastomeric, permanently flexible bonding and sealing materials based on a silicone rubber polymer. Unlike epoxy or acrylate adhesives that cure to a rigid solid, silicone adhesives retain their elasticity after cure, accommodating differential thermal expansion, vibration, and mechanical movement between bonded components without cracking or losing adhesion.
DELO-GUM silicones cure through a moisture-activated reaction at room temperature. Curing progresses from the exposed surface inwards at a rate of 2mm per 24 hours, so joint design and layer thickness directly affect the time to full cure. Relative humidity in the production environment affects cure speed and should be controlled between 30 and 80% for consistent results throughout the year.
The properties that distinguish DELO-GUM from standard household or sanitary silicones are the adhesion performance and chemical resistance levels, which are formulated specifically for industrial bonding and sealing rather than decorative or general-purpose applications.
The key characteristics of DELO-GUM silicone adhesives are:
- Permanent flexibility: the cured adhesive retains elasticity throughout its service life, absorbing thermal expansion, vibration, and mechanical movement without stress transfer to bonded components
- Moisture cure at room temperature: no heat source, UV lamp, or mixing equipment required, with skin formation in 5 to 20 minutes at 30 to 80% relative humidity
- Wide temperature resistance: suitable for applications operating from sub-zero temperatures up to sustained elevated temperatures in industrial and automotive environments
- Weathering and ageing resistance: stable against UV exposure, humidity, and ozone over extended service life in outdoor and harsh environment applications
- Neutral cross-linking: selected grades cure without releasing acetic acid or other corrosive by-products, protecting sensitive electronic components from corrosion within the assembly
- High purity grades: formulations available with low ionic content and minimal outgassing for use in sensitive electronic or pharmaceutical adjacent applications
- Substrate versatility: adhere to glass, metal, plastic, and ceramic substrates, with a silicone primer available to improve adhesion on rigid or low-energy surfaces
Silicone Adhesive Resources
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DELO GUM Engineering Article
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Cure at rate of 2mm every 24 hours
Sealants like DELO-GUM are available as one-component products, curing through exposure to humidity. Thicker layers and full-surface areas take a bit longer until they are fully cured. DELO’s silicone adhesives exhibit significantly superior adhesive properties compared to conventional silicones typically used in household or sanitary applications.
Applications and Benefits of DELO GUM Silicone Adhesives
DELO GUM adhesives are designed for uses where permanent elasticity, effective sealing and long term environmental protection are required, rather than high structural strength. Their silicone based formulation makes them particularly suitable for assemblies that must accommodate movement and stress without loss of performance.
They are widely used in electronics for bonding, sealing, encapsulation and potting. In these contexts, they tolerate vibration and thermal cycling while providing reliable protection against moisture, chemicals and aging. Neutral cross linking systems and high purity grades further reduce the risk of corrosion on sensitive components.
In automotive environments, DELO GUM adhesives are commonly used as elastic sealants and fixing materials for housings and assemblies exposed to temperature extremes and weathering. They are selected for their ability to maintain flexibility and adhesion over time, delivering durable performance under harsh operating conditions.
DELO-GUM Applications
DELO-GUM silicone adhesives and sealants are used where permanent flexibility, moisture cure at room temperature, and long-term resistance to temperature extremes, weathering, and chemical exposure are required in the finished assembly.
Electronics Encapsulation and PCB Protection
DELO-GUM silicone adhesives encapsulate and protect PCBs and electronic assemblies inside plastic and metal housings where the cured material must remain flexible to absorb vibration and thermal cycling without transmitting mechanical stress to solder joints or component leads. High purity grades with neutral cross-linking cure without releasing corrosive by-products, making them suitable for use directly in contact with sensitive electronic components. DELO-GUM silicones are used to encapsulate PCBs in PolyOxyMethylene housing assemblies for fill-level sensors, where the adhesive seals components from the measured media while maintaining adhesion to both the housing and the FR4 substrate.
Sensor Sealing and Potting in Harsh Environments
In sensor manufacturing for industrial and automotive applications, DELO-GUM silicone adhesives pot and seal sensor elements inside housings where the assembly will be exposed to humidity, temperature cycling, and chemical media over a long service life. The permanently flexible cured material accommodates dimensional changes in the housing under thermal load without cracking or pulling away from the substrate, maintaining the environmental seal throughout the service life of the sensor.
Freezer Gasket Assembly and Sub-Zero Sealing
DELO-GUM silicone adhesives bond and seal silicone gaskets in freezer and cold storage equipment where the adhesive must maintain flexibility and sealing performance at sub-zero operating temperatures. The cured adhesive retains the same softness and elasticity as the gasket material itself, producing a continuous seal that does not harden or crack under sustained cold. High purity grades are available for use in environments where food or pharmaceuticals are stored, where low ionic content and minimal outgassing are a requirement.
Outdoor and Weathering Exposed Assemblies
DELO-GUM silicone adhesives are used in outdoor assemblies including lighting, automotive exterior components, and industrial enclosures where the bond or seal will be exposed to UV radiation, humidity, ozone, and temperature extremes over an extended service life. The silicone polymer base provides inherent resistance to UV degradation and weathering without requiring additional surface treatments or protective coatings over the bond line.
Injection Moulding and Casting Resin Demoulding
DELO-GUM silicones are used as release agents and separating materials in injection moulding and casting resin applications, where the non-stick surface properties of cured silicone prevent adhesion between the moulded part and the tool or mould surface, supporting clean demoulding without damaging the part or the tooling.
Got a Question About Silicone Adhesives?
Whether you’re developing a new product or refining an existing process, Inseto’s team of experts is here to help.
From selecting the right silicone adhesive to optimising your curing process, we provide technical guidance, documentation, and samples to support your application needs.
Example Applications Using Silicone Adhesive
DELO-GUM Silicone Adhesive Product Range
DELO-GUM Silicone Adhesive Products
- Room-temperature-curing
- Free of solvents
- Tension-equalizing
- Self-leveling
- Very good temperature resistance
- Used as: Sealant, encapsulant / potting compound
Product 3699
Properties
326,000 Viscosity
Silicone Adhesive
Red
Very flexible, suitable for use to 300ºC
Product SJ3096
Properties
400,000 Viscosity
Silicone Adhesive
Whitish / transparent
Very flexible, general purpose sealant and adhesive
Knowledge Base Articles
Related Products
FAQs
How do DELO-GUM silicone adhesives cure?
DELO-GUM silicone adhesives cure through a moisture-activated reaction at room temperature. Curing begins on contact with atmospheric moisture and progresses from the exposed surface inwards at a rate of 2mm per 24 hours. No heat source, UV lamp, or mixing is required. Relative humidity in the production environment should be maintained between 30 and 80% for consistent cure speed and results throughout the year.
How long does DELO-GUM take to reach full cure?
Skin formation occurs within 5 to 20 minutes of exposure to atmospheric moisture depending on the grade and ambient humidity. Full cure depth depends on layer thickness and can be calculated at 2mm per 24 hours. Assemblies with thicker bond lines or fully enclosed potting applications will require proportionally longer cure times before handling or testing.
What substrates do DELO-GUM silicone adhesives bond to?
DELO-GUM silicone adhesives adhere to glass, metal, plastic, and ceramic substrates. On rigid or low-energy surfaces, the silicone primer DELO-PRE 3003 improves adhesion and long-term bond durability. Surface preparation including cleaning and degreasing is required before application to achieve consistent adhesion across all substrate types.
Are DELO-GUM silicone adhesives safe to use near sensitive electronic components?
Selected DELO-GUM grades use neutral cross-linking chemistry, meaning they cure without releasing acetic acid or other corrosive by-products that could damage electronic components or cause corrosion within the assembly. High purity grades with low ionic content are available specifically for electronics encapsulation and potting applications where contamination of the assembly is a concern.
How do DELO-GUM silicone adhesives differ from standard household silicones?
DELO-GUM silicones are formulated for industrial bonding and sealing applications and offer significantly higher adhesion performance and chemical resistance than standard household or sanitary silicone products. They are supplied in industrial formats including 310ml Eurocartridges compatible with standard dispensing equipment, and are supported by full technical documentation, grade selection guidance, and application testing from Inseto.
What is the difference between DELO-GUM and DELO DUALBOND for sensor potting applications?
DELO-GUM silicone adhesives cure to a permanently flexible elastomer, making them suited to sensor potting where the cured material must absorb vibration and thermal movement without transmitting stress to the sensor element. DELO DUALBOND cures to a harder, more dimensionally stable bond line and is better suited to sensor potting applications where positional accuracy and dimensional stability of the encapsulated element are the primary requirements rather than flexibility.
Can I get samples or technical support from Inseto?
Inseto provides technical support, product documentation, and samples for the full DELO-GUM range. As the exclusive UK and Ireland DELO distributor, Inseto can advise on grade selection, surface preparation, primer requirements, and dispensing equipment for your specific application. Send an enquiry using the form below or call us on +44 (0)1264 334505.
Further Information
Applications
Bonding, Sealing, Encapsulation
Industry Segments
Electronics, Electrical and Mechanical Engineering
View more details about DELO-GUM on the DELO Website
https://www.delo-adhesives.com/products/adhesives/detail/delo-gum/
Region
Available from Inseto in the United Kingdom & Ireland
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