The UK leader in Stud Welding and Refractory products
Isofrax® Mastics are high-performance insulation materials composed of Isofrax alkaline earth silicate wool dispersed in high-temperature binders. Upon drying, these mastics form a strong insulating structure with low thermal conductivity. They can be caulked, trowelled, pumped, or moulded quickly and easily, making them ideal for filling, sealing, repair, and general packing applications in industrial furnaces and process equipment.
Engineered for low thermal conductivity, thermal shock resistance, low shrinkage, and excellent adhesion, Isofrax Mastics provide reliable performance while simplifying installation and maintenance processes.
Isofrax Mastics deliver effective high-temperature insulation solutions for fibre-lined and refractory systems.
| Property | Pumpable 120 | Mouldable 120 | Mouldable LDS |
| Colour | White | White | White |
| Use Limit Temperature | 1200°C | 1200°C | 1285°C |
| Product Form | Putty | Putty | Sticky Putty |
| Wet Density (kg/m³) | 1090 | 1140 | 1285 |
| Dry Density (kg/m³) | 270 | 340 | 525 |
| Application Method | Pump, Caulk, Trowel | Trowel, Mould | Hand/Trowel |
Isofrax Mastics are suitable wherever insulating, sealing, or repairing high-temperature fibre linings is required:
Isofrax Mastics are widely used across high-temperature industrial sectors and demanding refractory, maintenance, and thermal processing applications:
Selecting the correct Isofrax Mastic is essential to achieving optimum sealing performance, thermal efficiency, and service life. Factors such as operating temperature, joint design, substrate type, and application requirements should all be considered during specification.
Our technical team provides support across high-temperature insulation systems, refractory maintenance, and thermal process applications, helping ensure the most suitable Isofrax Mastic solution is specified for your operating conditions
Speak with our technical specialists to discuss sealing requirements, refractory repairs, and high-temperature insulation applications. We can assist with product selection, application guidance, and specification support to help maximise thermal performance and operational reliability.