Mixing guidelines:

1. Add 10 parts of BLUESIL ESA 7250 B E5  to 100 parts of BLUESIL ESA 7250 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. After mixing A and B parts, it is preferable to degas the product to eliminate the air bubbles that would be visible in the finished part and which would reduce the mechanical and dielectric properties. Degasing is generally carried out with a vacuum of 30 to 50 mbar releasing the vacuum several times during the operation. 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. BLUESIL ESA 7250 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 BLUESIL ESA 7250 A&B E5 at service temperatures.

4. Recommended curing temperature: 4 hours at 60°C , or 2 hours at 100°C , or 1hour at 150°C.
Certain materials that BLUESIL ESA 7250 A&B E5 may be in contact with when curing could inhibit the reaction. Especially troublesome materials are: sulphur-containing cured natural and synthetic rubber compounds (neoprene, latex, SBR), tin catalyzed silicone rubbers, amine catalyzed epoxies, PVC stabilized with tin salts and some polyurethane elastomers. 

BLUESIL ESA 7250 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 ESA 7250 A&B E5 is a two component, optically clear, high strength silicone elastomer. This silicone elastomer cures by a polyaddition reaction at room temperature. Curing can be accelerated by heating.

Optical Transparency;Optical Encapsulant;Protection;UV resistant

2 Part RTV

  • Optically clear.
  • High strength silicone elastomer.
  • Good pourability, for easy filling.
  • Possibility to adding fillers.
  • It is particularly suited for potting applications or wherever a tough, elastic and transparent protection is required.
  • Protection of electronic components and electrical engineering equipment by encapsulation or filling.
  • Opto-electronic connections.
  • Insulating photovoltaic cells. 

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




Viscosity4000PairedCompNF T 76102mPa.s




Viscosity750PairedCompNF T 76102mPa.s






hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1hardness_cd523e03-72a3-4261-93f9-36f7bbeeafb1Hardness52PairedMixDIN 53505sh.A
elongation_68a5ddf2-2baf-4e60-ac6f-0a8a18a758b2elongation_68a5ddf2-2baf-4e60-ac6f-0a8a18a758b2Elongation115PairedMixNF ISO 37%
tensile-strength_e61eb2e0-4dc3-47b0-a61f-b673f1b265dctensile-strength_e61eb2e0-4dc3-47b0-a61f-b673f1b265dcTensile strength6,2PairedMixNF ISO 37MPa





BLUESIL ESA 7250 B E5BLUESIL ESA 7250 B E5/our_offer/Product/90062023/90062022/BLUESIL-ESA-7250-B-E5