1. Mixing the two components

Remix each of the 2 components (parts A and B) every time before using.
To 50 parts of BLUESIL LSR 8555 HTR A adds 50 parts of BLUESIL LSR 8555 HTR B.
The two components are thoroughly mixed either by hand, or using an electrical or pneumatic mixer, on a low speed setting so as to limit the inclusion of air in the mixture.
Comment: it is also possible to use a dispenser/mixer suited to processing two component elastomers. Please refer to us.

2. Degasing

After hand mixing parts A and B, it is preferable to degas the products to eliminate the air trapped in the mixture. If the mixture is processed using a machine, each of the two parts is degased beforehand and air is not introduced during mixing.
BLUESIL LSR 8555 HTR A&B is degased under a 30 to 50 mbar vacuum.
The product will expand under the action of the vacuum to between 4 and 5 times its initial volume and bubble on its surface. These bubbles will disappear gradually and the mixture will sink back down to its initial volume. To complete degasing, simply wait for several minutes before releasing the vacuum; the product will then be ready to use.
A recipient with a high diameter/height ratio is better suited to quick degasing.

3. Curing

The higher the temperature, the quicker the curing. The table below gives the time required for curing for information purposes, of a 6 mm thick part at different temperatures:

​Temperature (°C)​Cure time (min)

Comment: post curing for 1 hour at around 150°C is recommended to achieve optimum mechanical performance levels.
The crosslinking reaction can be slowed down or even inhibited on contact with substances containing sulphur, amines, or tin salts.


BLUESIL LSR 8555 HTR B may be stored at a temperature below 40°C / 104°F for up to 12 months from its date of manufacturing.Please consult the Safety Data Sheet of this product.


BLUESIL LSR 8555 HTR A&B is a two component, addition cure, silicone elastomer. Curing occurs by heating.
BLUESIL LSR 8555 HTR A&B is a viscous liquid which transforms into a strong elastic material once cured.


2 Part RTV


  • Easy processing, due to the good fluidity of parts A and B (mixed in a 50/50 ratio).
  • Easy curing, indeed BLUESIL LSR 8555 HTR A&B has a high pot life at ambient temperature (around 3 days) and can cure, even in the total absence of air or humidity, so that neither the section thickness nor the degree of confinement have an effect on the speed and uniformity of curing of this elastomer. This curing becomes very fast above .
  • Good mechanical characteristics notably with a good compromise between tensile strength and resilience.
  • Excellent dielectrical properties and particularly high tracking and electrical arc resistance.
  • Highly hydrophobic with a high capacity for hydrophobic recovery in polluted atmospheres.
  • Outstanding fire behaviour.
  • Good adhesion capability on metals, epoxy resins and glass fibre when using primer PRIM PM 820.



  • Production of elastomeric sheds and housings for composite insulators and surge arrestors.
  • Production of cable terminations.
(Technology used: medium pressure moulding)


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