WACKER Primer G 791 A/B – Addition-curing primer for silicone rubber & substrate adhesion

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WACKER Primer G 791 A/B – Addition-curing primer for silicone rubber & substrate adhesion

✔ low solvent content
✔ straightforward processing
✔ 2 component mixing ratio 1:1
✔ excellent adhesion
✔ no drying necessary
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€22,41 Incl. BTW
SKU: S11678
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    ✔ low solvent content
    ✔ straightforward processing
    ✔ 2 component mixing ratio 1:1
    ✔ excellent adhesion
    ✔ no drying necessary

    Size chart

    ⚠️ For commercial and professional users only. WACKER® PRIMER G 791 A/B is a solvent-based industrial product that, according to the manufacturer's safety data sheets, is not intended for sale to private consumers. Both components are highly flammable and component B is classified as a reproductive toxicant. Work only in a well-ventilated area with the prescribed personal protective equipment.

    Premium addition-curing primer for professional silicone-on-silicone and substrate adhesion

    WACKER® PRIMER G 791 A/B is a two-component, addition-curing priming system diluted in an organic solvent. The primer is applied to the substrate and forms a firmly adhering primer film after curing. When an addition-curing silicone rubber is then applied to the primed substrate and vulcanized, a strong, lasting bond forms between the silicone rubber and the substrate. The two components are mixed in a 1:1 ratio by weight, have an active substance content of approximately 20 percent by weight, and a pot life of 2 to 3 days at room temperature. Component A is opaque to whitish, component B clear yellowish. The product is mainly used for bonding addition-curing silicone rubbers onto already vulcanized addition-curing rubbers.

    Key benefits

    • 1:1 mixing ratio by weight → simple, predictable dosing of component A and B without complex weighing steps.
    • Pot life of 2 to 3 days at room temperature → generous working time, extendable to about 1 week when cooled to 6 °C.
    • Active substance content approximately 20 percent by weight → thin, even film build-up by brush, dipping or spraying.
    • Curing 20 to 60 minutes at 100 to 120 °C → fast vulcanization of the primer film in an industrial process.
    • Maximum adhesive strength after about 4 days → post-curing at 70 to 150 °C further improves adhesion.
    • Specifically matched to POWERSIL® XLR® 630/640 → especially suitable for bonding onto vulcanized silicone rubber of the same grade.

    Typical applications

    • → Surge arresters and high-voltage components
    • → Cable accessories and cable fittings
    • → Insulators
    • → Bonding addition-curing WACKER® ELASTOSIL® RTV-2, LSR and R plus
    • → Bonding WACKER® POWERSIL® RTV-2 and LSR
    • → Adhesion improvement between addition silicones and already vulcanized silicone substrates

    Processing instructions

    1. Ensure the surface to be primed is dry and free from grease, oil, wax, dust, rust or other contaminants. Also remove any release-agent residue from a previous vulcanization cycle.
    2. Clean the surface with a non-polar solvent (for example mineral spirits, boiling range 80 to 140 °C), followed by a polar solvent such as acetone. Roughen very smooth surfaces by grinding until the shine disappears and remove loose particles.
    3. Homogenize component A and B separately before use.
    4. Mix A and B in a 1:1 ratio by weight. The pot life of the mixed product is 2 to 3 days at room temperature, extendable to about 1 week at 6 °C.
    5. Apply the primer in a thin layer by brush, dipping or spraying.
    6. Vulcanize the primer film for 20 to 60 minutes at 100 to 120 °C.
    7. Apply the silicone rubber preferably soon after heating, and no later than about 2 days after priming. Keep the primed surface free from contamination.
    8. Maximum adhesive strength is in some cases only reached after about 4 days. Post-curing the cured rubber at 70 to 150 °C further improves adhesion.
    ⚠️ Fire and health warning. Due to its high organic solvent content this is a highly flammable liquid (flash point component A −4 °C, component B 3 °C). Keep away from heat, sparks and open flames, do not smoke, and take measures against static electricity. Component B may damage fertility or the unborn child. Component A can form hydrogen on contact with bases, alcohols or acids. Use only in a well-ventilated area.

    Storage and shelf life

    Keep opened containers well sealed and store them cool and dry. The best-before date is shown per batch on the label. Storage beyond this date does not automatically mean the product is unusable, but the properties must then be checked for the intended use.

    About the manufacturer

    Wacker Chemie AG is a world market leader in the development and production of silicones for industrial and technical applications.

    Professional support

    Unsure about the right surface preparation, curing temperature or the combination with a specific silicone rubber? Our specialists are happy to help you achieve a reliable bond. Contact us for tailored advice.

    Our story

    Our story began with our father, the founder of Nedform BV. We— Roel, Rutger, and Rob Collaris —are his sons and wanted to bring his passion and knowledge to the online world. That's how SAM (Silicones and More) was born—a creative space for everyone.

    Whether you're a beginner, an expert, or an enthusiastic DIYer looking for the right tools, materials, and some guidance, you've come to the right place. We've worked with silicones, resins, and casting materials ourselves for years. That's why we not only deliver quality but also genuine support—based on experience.

    • Small team with a great love for creating
    • Honest advice and reliable materials!
    • We help makers bring their ideas to life.

    FAQs

    What is the delivery time of my order?

    Orders placed and paid for on business days will be shipped on the same day in most cases. Orders received on weekends will be processed on the next business day.

    We always do our best to ship orders as quickly as possible, but actual shipping times may vary due to high volume, stock availability, or carrier circumstances.

    Delivery time depends on the destination country and the carrier. Below is a general indication:

    • Netherlands: usually within 1 business day
    • Belgium & Germany: typically within 1–2 business days
    • Other countries: depends on the destination and the local carrier

    Please note: these are guidelines, not guarantees. The final delivery time may differ due to factors beyond our control, such as sorting center delays, public holidays, or exceptionally high volume.

    What is the return policy?

    We offer a 30-day return policy as an added service. If you'd like to return an item or if there's something wrong with your order, please email us at info@siliconesandmore.com with your name and order number within 30 days of delivery. We'll help you quickly. The full terms and conditions can be found on our returns page.

    How can I track my order?

    Once your order has been processed and shipped, you'll receive a track and trace code by email, allowing you to easily track your package. Please note that it can sometimes take up to 24 hours after processing for the track and trace to be active.

    I have a problem with my order, how can I reach you?

    If you have any questions or run into any problems, please feel free to contact us via our contact page or email us at info@siliconesandmore.com . We'll be happy to help you quickly.

    If you want an immediate answer, ask our chatbot. They have extensive knowledge of all our products and can often help you right away!

    Can I also order for business purposes?

    Yes, business orders are possible . Customers within the EU outside the Netherlands can order VAT-free with a valid EU VAT number (0 percent intra-Community supply).

    Enter your VAT number on the shopping cart page , not at checkout.

    Go to the shopping cart via the link below and enter your VAT number and email address, after which the VAT will be automatically removed.

    https://siliconesandmore.com/cart

    Please note that if you only enter your VAT number at checkout, it will not be processed correctly and VAT may still be charged.

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