Cast iron is 20% more heat-capacious and 30 times more thermoconductive than any stone. That is why cast iron cores laid in the stove enable a significantly faster warmup of the stone layout and the steam room.
Cast iron cores do not crack or break up due to temperature differences.
Why we do not recommend to use cast iron cores exclusively? Because they produce very hot and dry steam. To balance its humidity and get comfortable, soft, and healthy steam, use a mixed layout of cast iron cores and stones.
Density: 7200 kg/m3.
Specific heat capacity: 0,5 kJ/kg°C
Compressive strength: 500 to 1100 MPa
Melting point: 1100 to 1200 °C
How to use:
Lay cast iron cores upon the bottom of the stove. Lay natural stove stones (rodingite, porphyrite, dunite, chromite, etc.) upon the cast iron cores, with the remainder of such ores being mixed with stones in a 30-to-70 proportion (30% cores, 70% stones).
Using cast iron cores with Vitau stove stones, you will heat your stove and steam room quickly. Enjoy your sauna!