Single component hybrid construction sealant / adhesive

flexothane® 45 is a thixotropic, VOC free moisture curing hybrid sealant / adhesive. It is a filled, moisture and oxidation resistant, mastic that exhibits excellent adhesion to cementitious and steel substrates.


flexothane® 45 can be used as a general joint sealer on low movement joints, a crack filler on cementitious surfaces, and also as an adhesive on a wide range of substrates. It provides medium chemical, wear and corrosion resistance, while at the same time curing to a 45 Shore A hardness (± 5 Shore A). A degree of colour change with time is to be expected.

  • One-component, easy to gun
  •  Oxidation resistant
  •  VOC free
  • Non-tack/does not pick up dirt
  •  Crack filler on cementitious substrates
  • Good adhesion on the most common construction materials
  • Good weathering and aging properties
  • Medium chemical and wear resistance
Surface Preparation

All surfaces are to be clean sound and free of moisture, dust, laitance and oil.


If applied to natural stone, we recommend the use of flexoprime® 105.

Back-up material

Suitable back-up materials must be used to adjust sealant depth in the joint. dura.cord is self-releasing material, but if dura.sheet,   soft-board or cork has been used as the joint filler and the sealant is going to applied without dura.cord a plastic strip bond breaker (polyethylene) must be placed on the filler surface before sealant is applied.

Protection of adjacent surfaces

Masking tape applied to areas adjacent to the joint will protect them from contamination and enable the joints to be finished in a neat line. The tape should be applied after the joint has been prepared, prior to any priming or sealing operation and removed after all finishing and tooling operations have been completed, but before the sealant has cured.

Typical Physical Properties

(download datasheet)


Place sausage in the barrel gun, cut end off of sausage and fit the nozzle; trim the tip to suit the joint spacing to be filled. Insert backing rod to the correct depth. Gun the product into clean joints that are free of loose material and laitance, then smooth with a dry spatula. The joint width should be designed to accommodate the expected movement, a width to depth ratio of 2:1 should be respected and a minimum width of 6 mm and a maximum of 20mm should be adhered to (10 mm in depth).


Tooling of sealants is necessary to avoid air entrapment and to assist in wetting out the surfaces to which the sealant is applied.  The surfaces of the joint should be smoothed with a clean knife or spatula. A mild solution of liquid soap and water can be sprayed onto the tooling spatula if required.

Model specification

The sealant will be flexothane® 45, a single-component, hybrid, moisture curing sealant/adhesive that is VOC free applied in accordance with the recommendations of a.b.e.® Construction Chemicals.

Tools should be cleaned immediately after use, and before the material has cured, with abe® super brush cleaner followed by washing with soap and water. Once the product has polymerize it may only be removed mechanically.

600 ml cartridges packed 12 per box.

Handling & Storage

This product has a shelf-life of 12 months if kept in a dry cool place in the original packaging. In more extreme conditions this period might be shortened.

Health & Safety

Uncured flexothane® 45 is toxic and should not be allowed contact with skin and eyes. The use of gloves and eye protection is advised. Splashes into eyes should be washed immediately with plenty of clean water and medical advice sought. Ensure the working area is well ventilated during application and drying. Always wear gloves when working with the material and avoid excessive inhalation and skin contact.
Cured flexothane® 45 is inert and harmless.

Important Note

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.® Construction Chemicals endeavors to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot – because a.b.e.® has no direct or continuous control over where and how a.b.e.® products are applied – accept any liability either directly or indirectly arising from the use of a.b.e.® products, whether or not in accordance with any advice, specification, recommendation, or information given by the company.

Further Information

Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements.