Remix each of the 2 components (parts A and B) every time before using.
BLUESIL RTV and can be mixed in any proportion so as to adjust the pouring viscosity to the required value.
2. Mixing the two components
Add 10 parts of BLUESIL RTV 147 B to 100 parts of BLUESIL RTV or RTV .The two components are thoroughly mixed using an electrical or pneumatic mixer, on a low speed setting so as to limit the inclusion of air in the mixture.
After mixing parts A and B, it is preferable to degas the products to eliminate the air bubbles that would be visible in the finished part and which would reduce the mechanical and dielectrical properties.
Degasing is generally carried out with a vacuum of 30 to 50 mbar releasing the vacuum once or twice during the operation.
Due to its viscosity, BLUESIL RTV 147 is particularly long to degas. A recipient with a high diameter/height ratio is better suited to quick degasing however the height must be sufficient to contain the swelling of the elastomer under vacuum conditions.
4. Pouring / encapsulating
BLUESIL RTV 147 and 148 are poured slowly and regularly.
In the case of a high thickness coating operation, the casting must be made at the lowest point in the volume to be filled this avoids forming and including air bubbles in the volume. It should not be filled totally to allow expansion of the RTV at service temperatures.
Demoulding is possible after approximately 24 to 48 hours at room temperature. Curing at room temperature allows virtually no linear shrinkage to occur, however it stops the cured compound from reaching its optimum mechanical properties. Heat helps to accelerate curing. Recommended curing temperature, starting from the point at which the RTV is at the chosen temperature :
- 4 hours at 65 °C
- or 1 hour at 100 °C
- or 30 min at 150 °C
Comment : Certain materials that the RTV may be in contact with when curing could inhibit the reaction:
- Sulphur-containing cured natural or synthetic rubber compounds
- RTV's catalyzed with metal salts
- PVC stabilized with tin salts
- Epoxydes catalyzed with amines
If in doubt, it is recommended to carry out a test by applying a mixture of the two components A+B with a brush to a small area of the object.
It is also recommended to keep special degasing equipment for this type of RTV. Indeed, degasing of other products in the same container could pollute the latter and be detrimental to the curing of BLUESIL RTV 147 and 148.
Adhesion is achieved on most materials using PRIM PMB 821 (after degreasing beforehand with a solvent), applied by immersion or with a brush, then dried for 30 minutes at a minimum of .
Excess primer deteriorates the adhesion level. When PRIM PMB 821 does not give sufficient results, another primer can be recommended.
7. Reversion resistance
BLUESIL RTV 147 and 148 have good reversion resistance: after 7 days at 250 °C, the Shore A hardness only drops by around 15 points.
For certain applications it may be necessary to reduce the viscosity of BLUESIL RTV 147 and 148. To achieve this, before catalyzing, it is possible to add up to 10 % of BLUESIL FLD 47V100 more than 10% would greatly reduce the properties of the parts produced.
Make sure that packaging is hermetically closed again each time it is used.
|BLUESIL RTV 148 A may be stored at temperatures between -20°C / -4°F and 30°C / 86°F for up to 18 months from its date of manufacturing.||Please consult the Safety Data Sheet of this product.|
BLUESIL RTV 148 A
BLUESIL RTV 147 A & B and RTV 148 A & 147 B are two component, polyaddition reaction, room temperature curing silicone elastomers. Curing can be accelerated by heating.
It is possible to mix BLUESIL RTV 147 A and 148 A to give an elastomer of intermediary hardness. These mixtures are combined with BLUESIL 147 B in the proportions given in this technical datasheet.
After mixing the two components (parts A and B), BLUESIL RTV 147 and 148 form a flowing paste which transforms into an elastic material once cured. The reaction does not give off any heat.
High Temperature Protection
2 Part RTV
- Possible to cure quickly by heating to with curing taking place without any bubble formation.
- Good reversion resistance.
- Very good heat stability.
- Good heat stability in confined environments.
- Producing thermal protection.
- Producing flexible, moulded insulators.
- Producing moulded joints.
- Encapsulation protection of electrotechnical systems.
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