Sodium Silicate

High-temperature adhesive for perlite refractory insulation. Mix lye and water in heat resistant container. This is an exothermic reaction.

Add in Silica Gel. This is another exothermic reaction.

If the gel is not disolving, add some heat to help it disolve quicker. Once it gets going, the reaction may get sufficiently exothermic to start boiling itself.

Stir and heat until all gel is disolved into a clear liquid.

This can be used as an adhesive for making high-temperature insulation. Just mix it with perlite and wait for it to set.
Adding a pinch of Plaster of Paris can help it to set faster.

Aaron Birenboim