A liquid solution of binders. The solution is designed for very rapid drying and is flammable.
Hardening of moulds, especially foundry sand moulds in areas where there is high turbulence. It also allows sodium silicate bonded moulds to be stored for up to a year before use.
Mould hardener can be brushed on or sprayed on. Use between half a litre and two litres per square metre. This will give a penetration of between 1mm and 4mm.
Hardening will occur as soon as the solvents have evaporated. To speed up the drying, ignite the surface with a match.
Clean the spraying equipment or paint brushes thoroughly with solvent after use. Application by a "swab" or rag is convenient, if the equipment can be burned after use. This stuff is seriously sticky, and it usually pays to wear gloves when working with it. If you struggle to get it all off your hands, just dry your hands well ,as with a hot air blower, and once dry the stickyness almost disappears.
Read the safety data sheet.