Very precise. Thanks for sharing. What is an ideal ventilation we can add to the drum tho?It's kind of a long process to be able to write here, but I'll try to sum it all up really quickly. Firstly, you just need a steel drum or a barrel you can use as the outer shell. You can be creative as much as you want because this is like its outer covering. You put insilation inside using bricks or ceramic fiber to keep it hot and burning. Maybe then you can decide on whether to use a burner or a charcoal setup for it. The former I think is more modern because the burner will be attached externally to a propane tank. Add a ventilation to this drum and then test it. Just make sure you dom't scald yourself doing it.
You'll need high-temperature insulation, such as Kaowool, a good refractory lining, and a burner that can easily reach 1000°C for your corn steel heater idea. I've built a small metal-melting furnace before. Propane is your most straightforward option. If you are using the melt chamber for two purposes, be sure to separate it from the rest of your heat exchanger setup. Hope this helpsi need to create a corn steel heater which ill be also using to melt other metals as needed so i could use some help if someone here has done that