21 Inexpensive Sauna and Wood-Burning Hot Tub Design Ideas. My grandma and grandpa were from Finland. Every Fin had a sauna. and he always built very cool sauna's in each house he owned.
Untreated sauna benches and panel walls can be blackened using the Supi Sauna Wax by Tikkurila. This water-soluble solution with natural wax is colourless but it can be tinted black.