Remix each of the two components (base + catalyst) before each use.


1. Mixing the two components
Add 10 parts of BLUESIL RTV 141 B E5  to 100 parts of BLUESIL RTV A E5. 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. A dispensing machine can also be used.

2. Degasing
After mixing parts A&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 several times during the operation. This product 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.

3. Pouring the mixture
BLUESIL RTV 141 A&B E5 is 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.

4. Curing
At 23 °C, demoulding of BLUESIL RTV 141 A&B E5 is possible after approximately 24 to 48 hours at room temperature. Heat helps to accelerate curing.
Recommended curing temperature:
4 hours at 60 °C
or 2 hours at 100 °C
or 1 hour at 150 °C


Comment: Certain materials that the RTV may be in contact with when curing could inhibit the reaction:

  • Sulphur-containing cured natural and synthetic rubber compounds
  • RTV's catalysed with metal salts
  • PVC stabilized with tin salts
  • Epoxydes catalysed with amines

If in doubt, it is recommended to carry out a test beforehand. 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 141 A&B E5.

5. Adhesion
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 approx. 25 °C. For optimum adhesion, the RTV must be poured within the following four hours.
Excess primer deteriorates the adhesion level. When PRIM PMB 821 does not give sufficient results, another primer can be recommended, please consult us.

Specific case of repair work:

An object coated in BLUESIL RTV 141 A&B E5 can be repaired: after cutting, simply make up the volume of elastomer with more, new BLUESIL RTV 141 A&B E5 which has strong self adhesion without the need for a primer.

Repair of BLUESIL RTV 141 A&B E5 is invisible in the transparent bulk however, the incision should be made at the last minute to avoid any soiling of the surfaces before the new product is poured in.

Make sure that packaging is hermetically closed again each time it is used.

BLUESIL RTV 141 A E5 may be stored at temperatures between -20°C / -4°F and 30°C / 86°F for up to 24 months from its date of manufacturing.Please consult the Safety Data Sheet of this product.


BLUESIL RTV 141 A&B E5 is a two component, polyaddition reaction, room temperature curing silicone elastomer. Curing can be accelerated by heating. After mixing the two components BLUESIL RTV 141 A&B E5 forms a relatively low viscosity, colorless liquid which transforms into an elastic and transparent material once cured. The reaction does not give off any heat.

Optical Encapsulant;Optical Transparency;Protection;UV resistant

2 Part RTV

  • TRANSPARENCY, good optical transmission.
  • GOOD POURABILITY, for easy filling.
  • Possibility of adding fillers.
  • Good reversion resistance in confined spaces.
  • Coating or potting protection of electronic components and electrotechnical equipment.
  • Opto-electronic links.
  • Insulation of light sensitive cells.
  • Sheathing of step index optic fibers.

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




Viscosity3500PairedCompNF T 76102mPa.s









hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1Hardness50PairedMixDIN 53505sh.A
elongation_68a5ddf2-2baf-4e60-ac6f-0a8a18a758b2elongation_68a5ddf2-2baf-4e60-ac6f-0a8a18a758b2Elongation120PairedMixNF ISO 37%
tensile-strength_e61eb2e0-4dc3-47b0-a61f-b673f1b265dctensile-strength_e61eb2e0-4dc3-47b0-a61f-b673f1b265dcTensile strength6PairedMixNF ISO 37MPa





BLUESIL RTV 141 B E5BLUESIL RTV 141 B E5/our_offer/Product/90062024/90062027/BLUESIL-RTV-141-B-E5