Refractory

Refractory is a single-component grey refractory mastic, completely asbestos-free. After complete hardening it forms a rigid mass which, thanks to the formulation based on stabilized silicates – as binders – and a mixture of aluminium, silicon and potassium oxides and hydroxides – as pyrogen-free fillers – maintains a high resistance even when exposed to open flames. The selected fillers do not lead to any loss of volume at high temperatures, thus ensuring a perfect seal of the joint even at temperatures of 1000 °C. The thixotropic consistency guarantees excellent vertical workability, without dripping material which, however, thanks to its fluidity, is easy to work. Once exposed to high temperatures, the colour of the hardened mass lightens and turns into a pale pink colour, but this does not affect the refractory characteristics of the material.

Instructions for use

1. Moisten porous substrates such as concrete or bricks before applying Refractory. Previously clean and degrease smooth surfaces.
2. Use special mechanical or pneumatic guns and choose the diameter of the extrusion nozzle according to the size of the joint.
3. Introduce an excess amount of mastic into the joint cavity in order to apply pressure to the material during smoothing and to facilitate filling without voids and better adhesion on the sides of the joint.
4. Be very careful not to introduce air bubbles, as they lead to the formation of preferential routes for water evaporation and can therefore encourage the formation of cracks.
5. Smooth before surface filming, specifically within the first 20 minutes after extrusion.
6. In the case of applications subject to mechanical stress, it is recommended to apply a layer of glass fibre between two coats of product.

Tools cleaning
While the mass is still fresh, water is sufficient. Once hardened, it can be removed only mechanically.

Storage

Protect from frost. In the closed original packaging the product is stable for at least 12 months.

Warnings

The mastic hardening takes place from the outside to the inside. Therefore the waiting time for mass exposure to high temperatures depends on the thickness of the product layer applied. However, it is recommended to wait at least 24 hours after extrusion before heating the hardenedmass and to heat it gradually to avoid the formation of bubbles.

Once hardened, the product is rigid and therefore not suitable for elastic sealing.