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

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Wacker

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 Read more

€22,41 Incl. BTW

SKU: S11678

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1.3 Kg Set [0.65 Kg A + 0.65 Kg B]
100 gram Set [50 gram A + 50 gram B]

1.3 Kg Set [0.65 Kg A + 0.65 Kg B]

€187,08

€143,90/kg

100 gram Set [50 gram A + 50 gram B]

€22,41

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✔ low solvent content
✔ straightforward processing
✔ 2 component mixing ratio 1:1
✔ excellent adhesion
✔ no drying necessary

⚠️ 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

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.
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.
Homogenize component A and B separately before use.
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.
Apply the primer in a thin layer by brush, dipping or spraying.
Vulcanize the primer film for 20 to 60 minutes at 100 to 120 °C.
Apply the silicone rubber preferably soon after heating, and no later than about 2 days after priming. Keep the primed surface free from contamination.
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.

Safety Information

GHS classification: highly flammable liquid and vapour (H225). May be fatal if swallowed and enters the airways (H304). Causes skin irritation (H315) and may cause drowsiness or dizziness (H336). May damage fertility or the unborn child (H360FD, component B). Toxic to aquatic life with long-lasting effects (H411). Component B contains a substance of very high concern (1,2-dimethoxyethane). Recommended personal protective equipment: chemical-resistant gloves (fluororubber or PE/EVOH laminate), tight-fitting safety goggles, protective clothing and, where ventilation is insufficient, respiratory protection with an ABEK filter. Use only in a well-ventilated area, away from ignition sources, and do not eat, drink or smoke while working. Wash hands thoroughly after use. This is a summary. Always consult the full Safety Data Sheet (SDS) for component A and component B for complete hazard information before working with this product.

Safety Pictograms	Safety Data Sheets (SDS)
	📥 EN SDS WACKER PRIMER G 791 A 📥 EN SDS WACKER PRIMER G 791 B

Signal Word	H‑code	Hazard Statement	P‑codes	P‑statements
Danger	H225	Highly flammable liquid and vapour	P210 P233 P240 P241 P280 P303+P361+P353 P370+P378	Keep away from heat, hot surfaces, sparks, open flames and other ignition sources Keep container tightly closed Ground and bond container and receiving equipment Use explosion-proof equipment Wear protective gloves/clothing/eye protection/face protection IF ON SKIN (or hair); take off immediately all contaminated clothing. Rinse skin with water/shower In case of fire; use appropriate extinguishing media
Danger	H304	May be fatal if swallowed and enters airways	P301+P310 P331 P405 P501	IF SWALLOWED; immediately call a POISON CENTER/doctor Do NOT induce vomiting Store locked up Dispose of contents/container in accordance with local regulations
Warning	H315	Causes skin irritation	P264 P280 P302+P352 P333+P313	Wash thoroughly after handling Wear protective gloves/clothing/eye protection/face protection IF ON SKIN; wash with plenty of water and soap If skin irritation or rash occurs; get medical advice/attention
Warning	H336	May cause drowsiness or dizziness	P261 P271 P312	Avoid breathing vapours/spray Use only outdoors or in a well-ventilated area Call a POISON CENTER/doctor if you feel unwell
Danger	H360	May damage fertility or the unborn child	P201 P202 P280 P308+P313 P405 P501	Obtain special instructions before use Do not handle until all safety precautions have been read and understood Wear protective gloves/clothing/eye protection/face protection IF exposed or concerned; get medical advice/attention Store locked up Dispose of contents/container in accordance with local regulations
Warning	H411	Toxic to aquatic life with long lasting effects	P273 P391 P501	Avoid release to the environment Collect spillage Dispose of contents/container in accordance with local regulations

More information about H and P statements: UK HSE &ECHA

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.

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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.

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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.

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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).

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

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

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