Elastomeric Fuel Resistant Sealant

flexothane® HS is a two part, cold applied elastomeric fuel resistant joint sealant based on a polyurethane and tar blend.


flexothane® HS is suitable for flexible joint sealing in applications such as:

  • concrete pavements
  • asphalt pavements
  • garage forecourts
  • fuel depots
  • transport and cargo depots
  • Very good flexibility
  • Chemically resistant to fuel, oils and hydraulic fluids making it suitable for numerous applications
  • Self leveling and very easy to apply without the need to tool
Typical Physical Properties
 Base Viscous liquid
Curing agent Liquid
Color Black
M.A.F. 25%
Reaction type Chemical cure
Trafficable 24 hours
Full cure 7 days
Shore A hardness 15 to 20
Chemical resistance to occasional spillage Resistance to dilute acids, mild alkalis, petrol, aviation fuels, diesel fuels, synthetic oils, mineral oils, hydraulic fluids, kerosene and white spirit
Solids content 100%
Relative Density 1,36 kg/litre
Flash point > 62 °C
Coverage for Estimating Purposes
 Joint size in mm Litre per meter
10 x 10 0,100
13 x 13 0,169
15 x 15 0,225
20 x 15 0,300
20 x 20 0,400
25 x 20 0,500
25 x 25 0,625
30 x 25 0,750

One litre of flexoprime® A or C is normally sufficient for 20 litres of flexothane® HS. Figures quoted are theoretical and no allowance has been made for wastage or the varying porosity of the concrete to which it is to be applied.

Joint Geometry

 The minimum joint width for flexothane® HS is 6 mm. The width of joint to be sealed should be four times that of calculated movement. For joints up to 12 mm in width the sealant depth must equal the joint width; for joints 12 mm to 24 mm wide the depth must be 12 mm and finally for joints greater than 24 mm in width, the sealant depth must be half the width. The joint faces must be parallel.

Surface Preparation

Thorough preparation of joints is essential to obtain a satisfactory seal. Concrete surfaces must be clean sound and dry, all traces of dust, laitance, mould oil, any previous sealant and all other foreign material must be removed by mechanical grinding, followed by blowing out with dry oil-free compressed air.

Refer to the “Preparation of Surfaces” datasheet for further information.

Bonding / Priming

Porous surfaces must be primed with flexoprime® C brushed well into the joint face, allowing the solvent to evaporate. The surface should be touch dry in 30 minutes to 2 hours subject to temperature and relative humidity.

flexothane® HS must be introduced into the joint during this time period. If this period is exceeded another coat of primer must be applied.

Where flexothane® HS is in contact with asphalt, flexoprime® A must be used to prime this surface, brushed well into the joint face, allowing the solvents to evaporate. The surface should be touch dry in 30 minutes to 2 hours, subject to temperature and relative humidity.


Place the entire contents of the activator into the base and thoroughly mix for approximately 4 minutes using a suitable mixing paddle attached to a slow-speed drill (300-400 r/min). It is essential to ensure that the base and activator are thoroughly mixed, periodically scrape the sides and bottom of the tin while mixing and ensure that the mix obtained is homogeneous, smooth and consistent. Re-mix where necessary.

Note: It material is not mixed thoroughly, it’s performance will be impaired.

Back-Up Material

Suitable back up material must be used to adjust sealant depth in the joint to comply with the joint geometry cited in the table. duracord is a self-releasing material, but if soft-board is used as the joint filler, a plastic strip bond breaker must be placed on the filler surface before sealant is applied.


flexothane® HS may be poured directly from the container when joints exceed 25 mm. However it is always recommended that flexothane® HS is applied using a suitable sealant gun ensuring that the sealant is set 4 mm below the operational surface of the concrete or asphalt pavement. flexothane® HS is a self-leveling sealant and no tooling is required. 


Tools and mixing equipment should be cleaned immediately after use, and before the material has set with abe® super brush cleaner, followed with washing with soap and water.

Protection on Completion

The finished sealant should be protected from heavy traffic until the sealant has fully cured. Over-painting of sealant is not recommended.

Application Temperature

Surface and ambient temperature must be at least +5°C and rising ideally between 20°C and 30°C. Lower temperatures will extend the curing period. 


Refer to “Coverage for Estimating Purposes” for anticipated coverage.

Model Specification

Heavy-duty pavement sealant for cold-sealing of joints in concrete paved areas. Fuel resistant.

The sealant will be flexothane® HS, a two-component, cold-applied elastomeric sealant applied in accordance with the recommendations of a.b.e.® including primers flexoprime® A for asphalt and flexoprime® C for concrete.

The sealant will have a movement accommodation factor of 25% and be resistant to fuel, oil and hydraulic fluid.


flexothane® HS is supplied in 5 litre kits.

flexoprime® A and C are supplied in one litre tins.

Health & Safety

Uncured flexothane® HS contains coal tar and is toxic and flammable. Ensure the working area is well ventilated during application and drying. Avoid naked flames in the vicinity. Gloves should always be worn to avoid skin contact. Also avoid excessive inhalation of fumes. If the product is splashed in the eye, wash with plenty of clean water and seek immediate medical attention. It is imperative that after handling the product, hands must be thoroughly cleaned before eating or smoking.

flexoprime® C is a highly flammable liquid and must not be used near a naked flame. It is also advisable to wear gloves during application of the primer and thorough washing of the hands after use is strongly advised.

Handling & Storage

flexothane® HS has a shelf life of 12 months if kept in a cool, dry place in the original packaging. Ideal storage temperature of 25 °C, Storage in temperatures above 25 °C may reduce shelf life.

Important Note

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.® endeavours to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot accept any liability for application – because a.b.e.® has no direct or continuous control over where and how a.b.e.® products are applied.

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

a.b.e.® has a wealth of technical and practical experience built up over the years in the company’s pursuit of excellence in building and construction