High Temperature Stove & Flue Sealant 1500°C - 310ml Black

High-temperature stove and flue sealant, rated to 1500°C (2732°F), is a silicate-based black paste purpose-made for sealing solid-fuel stove and flue joints. Rather than remaining a flexible rubber-like compound, it solidifies under heat into a rigid, ceramic-like finish that stays put for the life of the joint.

Standard "heat resistant" automotive silicones are typically rated to no more than 300°C and can turn brittle or fail under the sustained heat of a wood burner or multi-fuel stove. This sealant uses a different, silicate-based chemistry: rather than degrading, it vitrifies under heat into a hard, ceramic-like mass that bonds tightly to the surrounding surface, forming a permanent, smoke-tight seal against carbon monoxide and flue-gas leakage.

It is supplied as a smooth black paste in a standard 310ml (10.5fl oz) cartridge that fits any standard-thread sealant/caulking gun, and is thixotropic (non-slump), so it can be tooled into vertical and overhead joints without sagging. Once fully solidified and the appliance is brought into use, the joint should be slowly heated up to +250°C (482°F); as it reaches this temperature the sealant turns dark grey and becomes extra-hard, completing the cure.

Key Features

• Rated to 1500°C (2732°F) maximum service temperature: engineered specifically for solid-fuel stove and flue joints where ordinary silicone sealants fail.
• Silicate-based formula that vitrifies under heat into a rigid, ceramic-like mass rather than degrading like a standard heat-resistant silicone.
• Forms a permanent, smoke-tight seal that resists carbon monoxide and flue-gas leakage at static, non-moving joints.
• Thixotropic (non-slump) black paste that holds its shape when tooled into vertical or overhead joints.
• Supplied in a 310ml (10.5fl oz) standard-thread cartridge, compatible with any standard sealant/caulking gun.
• Net weight of 724g (1.6lb) per cartridge.
• Changes colour from black to dark grey and becomes extra-hard once heat-cured up to +250°C (482°F) in service.
• Bonds well to cast iron, mild steel, stainless steel, firebrick, concrete, stone and clay.

Specification

Typical Applications

Because it is formulated specifically for the sustained heat of solid-fuel appliances rather than general household or automotive use, this sealant is suited to hearth and flue jobs that sit well beyond the working range of an ordinary silicone. Typical applications include:

• Sealing the joint between a stove spigot and the flue pipe on a wood burner or multi-fuel stove.
• Bonding flue liners to register plates for a smoke-tight connection at the top of the flue run.
• Filling cracks in firebacks and resetting loose firebricks inside the firebox.
• Sealing pizza ovens and chimineas, which reach similarly high working temperatures.
• Bonding ceramic rope seals or sealing stove glass into cast iron stove doors.
• General hearth and flue maintenance and repair work on any joint that is static rather than subject to movement or vibration.

Because the cured sealant bonds well to cast iron, mild steel, stainless steel, firebrick, concrete, stone and clay, a single cartridge covers the great majority of solid-fuel hearth and flue repair jobs without needing a different product for each substrate.

Installation Guidance

1. Ensure all surfaces are clean, dry and free from rust, dust or grease before applying.
2. On porous substrates such as brick, clay or firebrick, lightly mist the surface with water first; this slows the surface skinning-over and reduces the risk of cracking as the sealant cures.
3. Load the cartridge into a standard sealant gun and apply the sealant into the joint.
4. Tool the joint to shape while the sealant is still workable; its thixotropic (non-slump) consistency holds its position in vertical and overhead joints.
5. Apply within the +5°C to +35°C (41°F to 95°F) ambient application temperature range, and leave the sealant to fully solidify before lighting the appliance.
6. Once the appliance is brought into use, allow the joint to slowly heat up to +250°C (482°F); the sealant will turn dark grey and become extra-hard as it completes its cure.
7. This is a rigid, vitrifying sealant intended for static joints only; do not use it where movement or vibration is expected.

Order before 2pm Mon–Fri for same-day dispatch from our UK warehouse.