Joint preparation:
The joint faces to be bonded must be clean, dry and free from dust, oil, grease, old sealant and any traces of contaminant which may affect adhesion. Surfaces should be degreased with solvent soaked cloth and then wiped with a clean cloth. To remove dust, use oil-free compressed air.


Although BLUESIL SLT 3B will bond well to most clean and dry surfaces, it is recommended that a primer be used on certain substrates in order to ensure a strong and uniform bond:

- Cast, extruded or anodised aluminium: BLUESIL PRIM 10073.


- Steels, ferrous metals, painted and most rigid plastics: BLUESIL PRIM 10073.

In the case of particularly porous materials, apply a second layer after drying.

Joint dimensions: 

The movement capability of sealants as well as local regulations must be considered. Joint width should be twice the depth.

Sealant application:
For good performance it is essential that the sealant is only bonded to the two facing sides of the joint. To achieve this, install a backup material (closed cell polyethylene or open cell polyurethane foam). Apply the sealant in a continuous operation making sure all air pockets or voids are eliminated. Tool the sealant with light pressure to spread the material against the joint surfaces.
This operation should be made with a dry spatula before skin formation occurs.
Excess uncured sealant should be wiped and cleaned with a commercial solvent, cured sealant can only be removed by scraping (i.e. with a razor blade), or with a special silicone remover product like BLUESIL SILICONE REMOVER.

BLUESIL SLT 3B TRANSLUCENT may be stored at temperatures between -5°C / 23°F and 50°C / 122°F for up to 24 months from its date of manufacturing.Please consult the Safety Data Sheet of this product.


BLUESIL SLT 3B is a one-component silicone sealant which when exposed to atmospheric humidity, cures rapidly to form a permanently flexible and extremely durable weather tight seal. The cured sealant will accommodate joint movement of maximal amplitude of 25 % throughout a wide temperature range. 

Resistance to severe weathering is excellent.

BLUESIL SLT 3B is available in the following colors: 

- Translucent, 

- White, 

- Black.


1 Part RTV Acetoxy

BLUESIL SLT 3B bonds strongly to clean uncoated glass, ceramics and glazed or painted surfaces without the need to prime. For most other substrates it is recommended that a primer be used, a range of high-performance primers is available which will ensure optimal bonding to most commonly encountered substrates.

After cure, BLUESIL SLT 3B will be resistant to many diluted acids and bases as well as salt spray, and will tolerate short exposure to most industrial solvents and hydrocarbon-based products. In the latter case some reversible swelling and softening will occur.

Once cured, BLUESIL SLT 3B is not affected by exposure to sunlight, rain, snow and ozone and maintains this resistance over many years.

The exceptional translucent quality of BLUESIL SLT 3B is such that it is ideally suited for use where the sealant is visually prominent, examples being, display cases and shop windows.

BLUESIL SLT 3B is a high modulus sealant and should be selected for use on applications where joint loads are high and where relative movement between substrates is to be minimised. When used on external joints a weathertight seal of high integrity will result.

  • All classical glazing joints
  • Door and window frames
  • Cladding and curtain wall construction
  • Shop windows, display cases, panels and signs
  • Portable buildings, caravans and containers
  • Conservatories and greenhouses
  • Heating, ventilation and air conditioning (HVAC) ducting
  • Construction joints
  • Swimming pools
  • Marine hardware

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




Elongation500MonocompNF ISO 37%
Hardness23MonocompISO 868sh.A
Tensile strength2.1MonocompNF ISO 37MPa