Seal-it® 235 ELASTO-STOP

Seal-it® 235 ELASTO-STOP is a high-quality, elastic putty for sealing and filling of heritage glass, based on silicone technology, that cures by moisture into a durable rubber that retains its elasticity.


  • Specially designed as a putty that retains its elasticity, for application of seam seals for single-pane, insulating and heritage glass, in wooden, steel and concrete frame rabbets.
  • As a higher-quality substitute for traditional putty in heritage and public buildings, such as canal-side buildings, farmhouses, schools, station buildings, etc.
  • As an elastic filler for smoothing/levelling surface damage such as screw and nail holes in glazing beads and other wooden parts.
  • Repair putty for damaged seals in seams, based on silicone technology.


  • Durable, retains elasticity, fast moisture-curing.
  • Excellent adhesion without primer on practically all surfaces, even when moist.
  • Superb workability using a professional caulk gun, due to the special yellow XL spout.
  • Easy to shape with a suitable jointing tool (PALU) and/or finishing block.
  • Good resistance to UV, weather, water, moisture and ageing.
  • Non-corrosive to metals.
  • Extremely low-maintenance, does not crack, split, wrinkle or petrify from drying out.
  • Compatible in direct contact with edge seals on insulating glass and PVB-laminated glass.
  • Isocyanate and solvent free.
  • Odourless, adhesive-free, bubble-free and non-shrink fast-curing hybrid system.

Application conditions

  • Application temperature (ambient and surface) between +5°C and +40°C.
  • On stable, compatible, clean, uncontaminated, grease-free and dust-free surfaces.
  • Use a suitable brush to remove any loose particles from the surface.
  • Degrease the surface properly using Seal-it® 510 Cleaner.
  • Seal-it® 235 ELASTO-STOP has a broad bonding spectrum, but highly porous surfaces should be pre-treated with Seal-it® 520 PRIMER and non-porous surfaces with minimal bonding should be treated with Seal-it® 525 Clean & Bond.
  • Minimum dimension of the seam seal (triangular joint): 10 mm x 10 mm.
  • Use a professional caulk gun fitted with yellow XL spout, shape using a scraper and/or finishing block.
  • Use Seal-it® 550 FINISH to apply a smooth and tight finish, before skin formation.

Standard product line


12 x 600 ml foil pack





SI-XXX-XXXX-XXX = Article number.
Other colours and/or packaging on request.


  • VOC emission class A+

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