Remix each of the two components (part A and B) every time before using

1. Mixing of the two components

Add 100 parts of BLUESIL RTV 4082/8 A to 10 parts of BLUESIL RTV 140/8 B.

The two components may be intimately mixed either by hand or using a low-speed electric or pneumatic mixer to minimize the introduction of air into the mixture.

2. Degassing

After mixing parts A & B it is recommended to degas the product to eliminate the air introduced in the mixture; if the material is processed using an automatic dosing machine, each of the two parts has been previously degassed and air is not introduced during the mixing.

BLUESIL RTV 4082/8 – RTV 140/8 is degassed under a 30 to 50 mbar vacuum.

When the vacuum is applied the product expands 3-4 times its initial volume and bubbles form on the surface. Once bubbles disappear the mixture collapses back to its initial volume. To complete degassing simply wait several minutes before releasing the vacuum, the product will then be ready to use.

Releasing the vacuum once or twice during the operation will improve and facilitate gas removal.

A container with a high diameter/height ratio will ease the operation as well.

Pour the degassed material slowly in a steady stream from one edge of the mould so that the material flows evenly over the mould minimizing the entrapment of air bubbles under the flowing rubber.

3. Crosslinking

At room temperature (23°C) BLUESIL RTV 4082/8 – RTV 140/8 cures in approximatively

24 hours, regardless the thickness of the mould. Room temperature curing assures the lowest possible shrinkage, if accelerated cure is desired, mild heat should be preferred.

To minimize shrinkage cure the elastomer at maximum temperature of 60°C for 3-4 hours, higher temperatures will cause higher shrinkage.

Conversely at lower temperature polymerization is much slower, at 20°C 36 hours may be necessary to complete cross-linking.

Be aware that contact with certain materials can inhibit the curing of this RTV:

  • Natural rubbers vulcanized with sulphur.
  • Polycondensation RTV catalysed with metal salts.
  • PVC stabilizing agents.
  • Amine cured epoxies.
  • Sulphur containing clays.

If doubts exist it is recommendable to run a quick test with a small quantity of material in order to assess compatibility. Take duly note that cross contamination due to not well cleaned tools or devices are frequently the main causes of inhibition. The best way is to use only dedicated gear when processing polyaddition RTVs.

BLUESIL RTV 4082/8 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 RTV 4082/8 A + XL 140/8 B is a two component silicone elastomer that crosslinks at room temperature by polyaddition reaction. The polymerisation can be accelerated by heat.

The silicone components are delivered as two components viscous liquids, which once mixed and cured, transforms into a grey, elastic and resistant material.

Polymerisation occurs without formation of heat.


2 Part RTV

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




Viscosity30000MonocompNF T 76102mPa.s
Density1.30PairedCompISO 2781g/cm3
Hardness40MonocompISO 868sh.A
AppearanceViscous liquidMonocompASTM D 412