I’m on a number of forums on other media, and kept answering the same questions primarily because those forums didn’t have the Bladeforums/Shop Talk education that I had. Most questions boiled down to a lack of understanding why forges and burners work. They simply copied what they saw on a youtube video or someone’s (inaccurate) rehash of Ron Reil’s page. Still, it took me like 10 minutes to type all this out, and it condenses hundreds of threads on here. Hopefully, the information is up to normal Shop Talk standards.
1. Blacksmithing and knifemaking, despite their similarities, have very different requirements for heat control, steel type, flux use, etc.
2. Burner’s don’t need flares in a forge, the chamber will sufficiently act as a flare. Try it, you’ll see.
3. Your burner is too far into the chamber. The tip should not be visible in the chamber.
4. Your burner is too long. The tube should be 6-8″ in length.
5. Your forge is starving for oxygen. Your burner holder(port) should be about 50% bigger than the burner tube and should NOT be stuffed with kaowool. This will allow it to get more air and burn hotter.
6. You only need 100k BTU for a propane tank forge, why do you have two or three burners?
7. Forced air does NOT use less gas than venturi or ribbon burners.
8. Coat your kaowool with something, uncoated kaowool is extremely bad for your lungs and it gets damaged quicker.
9. 1/8″ coating on your kaowool is plenty, you don’t need 3/4″. Refractory has little insulation value, it’s just protecting your lungs and the wool.
10. Those are hard firebricks. They have very little insulation value. You want to be using soft insulating firebricks.
11. A 55 gallon barrel is a bit big for a propane forge.
12. A straight down flame is OK for blacksmithing, but knifemaking works better with an angled burner that creates a swirling chamber.
13. Burners should be measured in BTU, not inches. 3/4″ or 1″ is meaningless with regards to BTU output. A BTU calculator is linked here BTU Calculator
14. Just because you saw someone do it that way on a YouTube video doesn’t make it the only way, or even the best way. My way isn’t the only way. But I have spent hundreds of hours testing different designs. I have sold over 1500 forges and 2000 burners and I’m just trying to help share my time and knowledge so you can accel in this hobby(Like Stacy did for most of us).
And here’s what you end up with if you follow these guidelines: