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Remix each of the 2 components (base and catalyst) every time before using.
1. Manually
- Catalysis:
BLUESIL RTV 1523 A&B should be mixed thoroughly in proportions of 100:100 by weight, by hand or with an electric stirrer rotating at low speed, to prevent the entrapment of air into the mix
- Degassing:
The mixture of the two components should be degassed to remove air bubbles which would reduce the mechanical and dielectric properties.
Degassing is generally performed in a vacuum of 30 to 50 mbars for about ten minutes, releasing the vacuum twice in the chamber.
Degassing will be quicker in a container with a large diameter to height ratio.

2. Mixing machine
Equipment consisting of two metering pumps enables the control of volumetric flow rates of parts A and B which are thoroughly mixed when they go through a dynamic mixing head or a static mixer.

3. Preparing of materials and pouring
BLUESIL RTV 1523 A&B can be poured on to metals, glass, laminates or moulded articles containing organic resins or silicones, or on all other materials.
The following procedure is recommended:

  • Clean the surfaces and remove grease with the appropriate solvent. Silicone elastomer surfaces should first be roughened, if possible, by rubbing with sandpaper.
  • Apply a bonding primer to all surfaces except silicones, with a rag or a brush. The most commonly used is BLUESIL PRIM PM 821, which requires a minimum of 30 minutes drying time at .
  • Slowly pour the degassed BLUESIL RTV 1523 A&B mixture at the lowest point of the volume to be filled, to prevent the formation and entrapment of air bubbles.

The container should not be filled completely, to allow the RTV to expand at working temperatures.

4. Curing
At a temperature of , BLUESIL RTV 1523 A&B cures in approximately 8 hours.
Curing can be accelerated by external heat, and the higher the temperature the faster curing will be. For example, at 150 °C the product cures in about 5 minutes.

5. Repairs
An object encapsulated with BLUESIL RTV 1523 A&B can be repaired simply by cutting away the RTV and replacing the missing elastomer with new BLUESIL RTV 1523 A&B, which adheres very strongly to itself with no need for a primer.


Curing of the RTV may be inhibited by contact with certain materials

  • Natural or synthetic rubbers vulcanised with sulphur derivatives.
  • RTV catalysed with metallic salts.
  • PVC stabilised with tin salts.
  • Epoxies catalysed with amines.

In case of doubt, a test should be made by pouring the mixture of the two components on to a small area of the object. It is also advisable to keep degassing apparatus exclusively for this type of RTV, as use with other substances might contaminate it and affect curing of BLUESIL RTV 1523 A&B.
Ensure that the packaging is hermetically sealed again each time it is used.


STORAGE -5°C No special storage precautions noted. Material is stable under normal conditions. Avoid contact with oxidizing agents. Suitable containers: polyethylene. Plastic lined steel drum.Please consult the Safety Data Sheet of this product.ELV;RoHS;WEEE


BLUESIL RTV 1523 A&B is a two-component silicone elastomer which cures at room temperature by a polyaddition reaction. The curing can be accelerated by heating.
BLUESIL RTV 1523 A&B is supplied in the form of a viscous liquid which is transformed, after mixing parts A&B and then curing, into a strong, elastic material.

Fire Protection;Protection

2 Part RTV




  • Outstanding flame resistance.
  • Dissipation of calories (encapsulation).
  • Low viscosity (easily refilled).
  • Advantageous mixing ratios (1/1):
  • Unaffected by inaccurate dosage.
  • Usable in two-component machines.
  • Fast curing time.

Additives range: Accelerator BLUESIL ACC PA 39 and retarder BLUESIL RTRD PA 40.



  • Coating and encapsulation in electro-technical and electronics applications.
  • Thermal and fire protection in the aerospace, nuclear and building industries.


Asia Pacific;Europe Middle East Africa;Central and South America;North America

For information about Storage and Shelf Life for this product, please download the Technical Data Sheet.




Viscosity4500PairedCompNF T 76102mPa.s




Viscosity4500PairedCompNF T 76102mPa.s






hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1Hardness50PairedMixASTM D 2240sh.A
pot-life_0d649a54-7503-4c7c-a047-9d0c4b3e9f6apot-life_0d649a54-7503-4c7c-a047-9d0c4b3e9f6aPot life90PairedMixmin





BLUESIL RTV 1523 BBLUESIL RTV 1523 B/our_offer/Product/90000442/90000439/BLUESIL-RTV-1523-B