I’m not saying that building a flamethrower is a responsible use of your time – but I’m not saying that you shouldn’t take the time to build one, either.
In January, Elon Musk’s Boring Company built 20,000 $500-flamethrowers and sold them all to the tune of $10 million. $500 is a lot of cheddar to throw at what basically amounts to a fancy tiger torch. Provided you’ve got the right tools on hand, as you can see in this video, it’s possible to build one for considerably less.
Disclaimer: Despite the fact that you can totally play with it, a flamethrower is not a toy. Always use fiery weapons that are the stuff of nightmares responsibly.