Heatmate Sealant everbuild

Heatmate Sealant

Temperature Resistant up to 300°C

Product Description

EVERFLEX HEATMATE SILICONE is a high modulus, reactive curing silicone sealant specifically designed for high temperature applications.  HEATMATE cures quickly to reduce dirt pick up.  It remains permanently flexible, forming a weathertight rubber-like seal.  


·         Excellent temperature resistance: remains flexible from   -50 - +300oC

·         Extremely low dirt pick up. – 1 hour tack free.

·         Orange/red colour – for easy installation identification (black also available)

·         Excellent adhesion to non-porous surfaces.

·         Waterproof seal           

Code Product Boxed In
080009 Heatmate Sealant (Black) 12

Areas For Use

·       Multitude of Industrial uses

·       As a gasket sealant.

·       For joints and assemblies, which must be resistant to high temperatures in ducting, metal chimneys, industrial/domestic ovens, heating appliances.




·       Do not use on porous surfaces such as brick, concrete and stone.

·       Do not use in conjunction with bitumen, lead or Asphalt.

·       Not for use on substrates that may bleed oils, solvent or plasticisers.

·       Do not use on soft metals such as lead or brass.

·       On temperatures above 285oC, slight discolouration may occur, but the joint will maintain its integrity.

·       Do not use above 300oC.



Surface Preparation

All surfaces must be clean, dry and dust free.  All loose or flaking surface coatings, and old sealant and mastic joints, should be removed before application. Highly porous substrates such as new plaster should first be primed with a dilution of Caulk with water at a ratio of 1:2. Can be applied to slightly damp surfaces.




The surfaces to be must be clean, dry and free from dust, grease and other contaminants.

Improve adhesion by wiping surface with white spirits. Priming is generally not required, although we always advise testing small areas prior to use.


Joint design should be as follows:

Minimum width: 6mm. Movement capacity will be impaired if the depth of the joint is greater than the width. For maximum movement accommodation, it is recommended that:

1.       The  joint depth should be no less than 5mm

2.       Joint depth should be 5mm for joints up to 10mm wide

3.       Joints above 10mm in width should be half the width in depth up to 20mm and  minimum 10mm for wider joints


Triangular fillets should be no less than 12mm across the face and should be finished with a flat or convex face. 


Cut the tip of the cartridge taking care not to damage the thread. Apply nozzle and cut at an angle of 45o with an opening slightly larger than the gap to be sealed. Apply using a standard sealant gun. Best results will be obtained by keeping an even pressure on the trigger and keeping the gun at a constant angle to the surface being sealed. To ensure a proper bond, always smooth the sealant down with a spatula or piece of wood wetted with linseed oil or white spirits. An improved joint appearance can be achieved by placing masking tape to both sides of the joint, removing within 5 minutes of application



Specific Data

Movement Accommodation

+ or – 20%

Skinning Time

5 mins @ 20°C

Cure Time

3mm per 24 hours

Hardness Shore A




Service Temperature Resistance

-50 to +300°C

Application Temperature

+ 5 to 40°C

Tensile Strength 

1.0 Mpa


0.3 Mpa

Specific Gravity



Uncured sealant: white spirit

Cured sealant: Silicone Eater

Minimum Joint Width


Maximum Joint Width     


Joint Ratio

Maximum depth 50% of joint width


@ 10 linear metres 9 x 9mm fillet joint



Health & Safety

Consult MSDS for full list of hazards




Store in cool dry conditions between + 5’C and 25’C. 

Shelf Life

24 months from date of manufacture.

File Download
Heatmate v2.doc
Everbuild Everflex Heat Mate Sealant SDS V2.1 190516.pdf