Single-component hybrid construction joint sealant
flexothane® 27 is a one-part, medium-modulus, moisture-curing hybrid construction sealant. It guns easily, holds a non-sag bead vertically or horizontally, is self-priming on most common building substrates and can be overpainted. Movement capability is 50% of the initial joint width.
Concrete joint preparation before sealing, Botswana
Product at a glance
System
Single-component, moisture-curing hybrid construction sealant
Modulus
Medium modulus — 0.25 – 0.40 MPa at 100%
Movement capability
50% of the initial joint width
Tensile strength
0.80 – 1.50 MPa
Elongation at break
Greater than 600%
Hardness
Shore A 25 ± 5
Skin cure
1 – 2 hours, depending on thickness, humidity and temperature
Cure rate
Approximately 2 mm per day, depending on humidity and temperature
Application temperature
5 °C to 35 °C
Service temperature
60 °C dry
Chemical resistance
Dilute acids, dilute alkali and general chemicals
Colour
Grey; other colours against order
Finish
Non-sag, non-tack — does not pick up dirt
Overpainting
Overpaintable with water- or solvent-based paints
Brand
a.b.e. Construction Chemicals
Availability
Ordered per project Ordered per project on confirmation, typically 10 – 12 working days.
Working days exclude weekends and Botswana public holidays, and run from order confirmation rather than from enquiry. Cross-border clearance can occasionally extend a delivery — we will tell you if it does. Tell us your programme date and we will work back from it. Lead times for a.b.e. Construction Chemicals are shown on the a.b.e. Construction Chemicals page.
Where flexothane 27 is used
General joint sealing on cementitious surfaces
Crack filling in concrete, stone and masonry
Joints in steel and other non-porous substrates
Vertical and horizontal joints, interior and exterior
Joints requiring an overpaintable, non-tack finish
Coverage & packaging
Pack sizes
280 ml cartridge and 600 ml sausage
Box quantities
600 ml sausages packed 20 per box; 280 ml cartridges packed 12 per box
Minimum fillet
Not less than 10 mm across the face, with a rounded convex surface
Back-up material
duracord® closed-cell polyethylene cord, where the gap exceeds 5 mm
Cleaning
abe® super brush cleaner
Shelf life
12 months from date of manufacture, stored below 25 °C
Note on quantities. Sealant quantity is worked out from joint width × depth × total run length, so take it off the joint schedule rather than from an area. Correct joint design and the right back-up depth matter more to whether the seal survives than the product does. Confirm against the current a.b.e. data sheet before ordering.
Specification clause
For architects, engineers and quantity surveyors writing this product into a specification or bill of quantities — the manufacturer's own wording:
The one part polyurethane construction sealant will be flexothane® 27, a single-pack, medium modulus, moisture-curing hybrid construction sealant as supplied by a.b.e.® flexothane® 27 will be applied in accordance with the recommendations of a.b.e.®
Reproduced from the a.b.e. Construction Chemicals technical data sheet. Confirm against the current issue before it goes into a tender document.
Before you specify it
Thorough joint preparation is essential. On concrete, stone and masonry remove all dust, laitance, mould release oil, previous sealant and foreign material by sandblasting or mechanical abrasion, then blow the joints out with dry, oil-free compressed air.
On glass, metal and other non-porous surfaces, clean with a suitable solvent — abe® thinners no. 3, IPA or MEK — after confirming the solvent is compatible with the substrate.
flexothane® 27 is self-priming on most common building substrates, but carry out a preliminary adhesion check before committing to the job.
Where the gap between adjoining surfaces exceeds 5 mm, insert a back-up material such as duracord® to set the sealant depth.
A triangular pointing fillet, where unavoidable, must be at least 10 mm across the face with a convex surface.
It is not recommended for use in water-retaining structures.
A degree of colour change over time is to be expected.
Carry out a compatibility test before application or before overpainting.
Tell us the substrate, the area and the exposure and we will confirm whether this is the right system, what preparation it needs, and what it will cost.
