Neutral silicone sealant


  • Good primerless adhesion on many substrates
  • Low odour during vulcanisation
  • Non-corrosive to metals
  • Rapid crosslinking – quickly becomes tack-free
  • Resistant to moisture and moulding
  • Resistant to UV radiation
  • Compatible with water-based and solvent-based coatings: no plasticizer migration

MAKROFLEX NX108 neutral silicone has good adhesion on different surfaces like glass, tiles, ceramics,  metals (aluminium, zinc, copper etc), impregnated, varnished or painted wood, plastics (PVC, epoxides, polyester, polyacrylate), and alkaline substrates (concrete, mortar). Excellent weatherability. It is resistant to ozone and ultra-violet radiation.

Application areas

  • Sealing of connecting and expansion joints in the building industry
  • Sealing of joints exposed to high levels of moisture e.g. sanitary field and bathrooms
  • Sealing of joints between glazing and supporting structures
  • Suitable for alkaline substrates such as concrete, mortar, fibrous concrete

The application temperature of the silicone must be at least +20°C. It is recommended to perform jointing at temperatures between +5°C and +40°C. At temperatures lower than +5°C, jointing can only be carried out if the joint faces are free of condensation, snow and ice.

Packaging: 300 ml cartridges


The product quality is preserved unchanged for 18 months after the date of production if stored in a cool (between +5°C and +30 °C), dry place in unopened cartridges.

How to use


Substrate preparation

If applicable, remove the old sealant cutting it out with a cutter. Then wipe out the remaining marks by using White spirit as helping solvent. Surfaces to be filled must be clean and dry. Especially greasy surfaces must be cleaned with acetone or MAKROFLEX CLEANER. White spirit can be used for cleaning metal surfaces. If the joint is filled with old sealant, which could make the adhesion poor, the old filling has to be completely removed and the surfaces cleaned. Apply masking tape on both sides along the joint in order not to overflow on the adjacent surfaces.


  • Place the cartridge into the silicone applicator.
  • The tip of the nozzle should be cut offaslant (at about 45 degrees) according to the joint width.
  • Apply the adhesive on the one of the joint surface by zigzag or small frequent points and wait for 5 minutes.
  • Pull the trigger to apply sealant into the joint. Ensure sealant is applied evenly and has good contact with both sides of the joint.
  • Apply the sealant between 2 adhesive strips, pushing forward to fill the join and make it watertight.
  • Smooth sealant with a smoothing tool within 5 minutes. Remove excess sealant immediately with a smoothing tool or your finger dripped in liquid soap (depending on the product).
  • Remove the tape before the sealant cures. The seal will be perfectly straight and smooth.


Tools and stained surfaces can be cleaned with white spirit before the sealant is cured.


MAKROFLEX NX108 should not be used:

  • For construction or glazing of fish tanks and aquariums – contains fungicides.
  • On natural stones – they may be stained in contact with sealant.
  • In contact with some organic elastomers  (neoprene) – sealant may be discoloured.
  • In contact with food applications.
  • On bitumen based surfaces – bad adhesion.