Optiflex 640

A high performance, fast curing, polyurethane joint sealant that offers a single component, moisture curing, non-slump, elastomeric seal with a good skin formation.


Product uses

  • Developed specifically for sealing dynamically moving joints – such as expansion and control joints.
  • Fills crevices and bridges gaps where a flexible polyurethane jointing compound is required, ie. steel bridges, fibre-cement butt joints.
  • Demonstrates high elasticity and recovery properties and therefore may be used to bond and seal most common building materials including concrete, glass, wood, stone, metal and anodised aluminium.



  • Durable resilient seal.
  • Excellent tear resistance and good weathering characteristics.
  • Primer free (except M1 smooth mortar).
  • Demonstrates good resistance to dilute acids and alkalis.
  • Non staining.
  • Has a good resistance to diluted
    acids and alkalis, ultra violet light and
    saline solutions.
  • Can bond to most coatings and be overcoated with most acrylics.



12m² per litre per application. Used at 10 % concentration. Dependant on width and
depth of joint.


Available Sizes

600ml sachets



Grey, White


While Optima Coatings makes every effort to ensure that paint colours match those shown on this website, variations will occur due to different computer screens. Please ask your Optima Coatings Technical Sales Consultant for more accurate colour swatches. To ensure consistency of sheen and colour, always check that paint containers carry the same batch number.