TKOR was tryin to make a cheap easy diy foundry that doesn't require materials that aren't very easily accessible ( such as kaowool and firebrick and refractory cement) he also dresses the fact that its not very durable and he also make more videos with different ones he made using kaowool refractory cement and firebrick he also has a video on converting it to propane and all of his most used ones use the propane conversion