WACKER® PRIMER G 791 A/B is a two-component, addition-curing primering system diluted in an organic solvent. The primer is applied to the substrate and after curing forms a primer film which firmly adheres to the substrate. Application of a silicone rubber onto the primed substrate and subsequent vulcanization will then result in a tight bond between the silicone rubber and the substrate.
This primer is suitable for all addition curing silicone (Silicone Addition ...) variants from our webshop.
Most addition curing silicone does not attach to a surface chemically. In order to promote the adhesion a primer should therefore be used.
Applications
• Arresters
• Cable Accessories
• Insulators
Bonding agent preferably used for bonding addition-curing silicone rubbers onto vulcanized, addition-curing rubbers (e.g. WACKER® ELASTOSIL® RTV-2, LSR and R plus or WACKER® POWERSIL® RTV-2 and LSR). WACKER® PRIMER G 791 A/B is especially suited for bonding addition-curing POWERSIL® XLR® 630/640 onto vulcanized silicone rubber of the same grade.
PLEASE NOTE. The primer has an ignition temperature of 3°C (from 3°C flammable gases will start to evaporate). PLease use caution!
Processing
Surfaces to be primed have to be dry and free from grease, oil, wax, dust, rust or other contaminants. Also mold-release agent from the previous vulcanization cycle on the silicone rubber substrate has to be removed. The surface should be cleaned, e.g. with a non-polar solvent such as mineral spirits (boiling range between 80 °C and 140 °C), followed by a polar solvent, such as acetone. Very smooth surfaces may be roughened by grinding until the shine of the surface disappears. Loose particles must be removed.
Components A and B must be homogenized before use. A and B are mixed in a ratio of 1:1 by weight. The pot life of the catalyzed primer mixture is 2 – 3 days at room temperature and can be prolonged by cooling to approx. 1 week at 6 °C. Storage must be in properly sealed containers.
Wacker Primer G 791 A/B [1.0] is applied in a thin film layer with a brush, by dipping or spraying. The primer film has to be vulcanized for 20 – 60 minutes at 100 – 120 °C.
The silicone rubber should be applied to the primed surface soon after the heating process, if possible. It is recommended that this is done not later than approximately 2 days after priming the substrate. Otherwise a drop in adhesive strength may occur. Prior to the application of the silicone rubber, the primed surface has to be kept free of contaminations.
Important Initial adhesion directly after vulcanization of the rubber will in many cases be high already. In some cases, however, initial adhesion will be sufficient for handling the composite while maximum adhesive strength will only be achieved after about 4 days. Additional post curing of the cured rubber at 70 °C – 150 °C will further improve adhesion. Once opened, containers of WACKER® PRIMER G 791 A/B should be kept well sealed and stored in a cool and dry place. For detailed information, refer to brochures on www.wacker.com.
Durability
At least 1 year. If stored between 10 and 25°C and out of direct sunlight.
Safety
H-CodeHazard Statements
H225 Highly flammable liquid and vapour.
H304 May be fatal if swallowed and enters airways.
H315 Causes skin irritation.
H318 Causes serious eye damage.
H336 May cause drowsiness or dizziness.
H361d Suspected of damaging the unborn child.
H373 May cause damage to organs through prolonged or repeated exposure.
H411 Toxic to aquatic life with long lasting effects.
P-Code Precautionary Statements
P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
P233 Keep container tightly closed.
P271 Use only outdoors or in a well-ventilated area.
P280 Wear protective gloves/protective clothing/eye protection.
P273 Avoid release to the environment.
P243 Take action to prevent static discharges.
P301 + P310 IF SWALLOWED: Immediately call a POISON CENTER/ doctor.
P331 Do NOT induce vomiting.
P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P310 Immediately call a POISON CENTER/ doctor.
P304 + P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P312 Call a POISON CENTER/ doctor if you feel unwell.
P302 + P352 IF ON SKIN: Wash with plenty of soap and water.
P332 + P313 If skin irritation occurs: Get medical advice/ attention.
P391 Collect spillage.
P370 + P378 In case of fire: Use extinguishing powder, alcohol-resistant foam or carbon dioxide to extinguish.
P403 + P235 Store in a well-ventilated place. Keep cool.
P501 Dispose of contents/container to waste disposal
Product information
Productinformatieblad Siliconen Primer Wacker G791
SDS Wacker Primer G791 A EN.pdf
SDS Wacker Primer G791 B EN.pdf
