/diy/ - Do It Yourself

How can I make a powerful butane torch?
Proper butane torch (pic related) is fine for its intended purpose (soldering domestic copper pipes, heating screws, etc), but it really sucks to braze with it.
I tried replacing butane gas with isobutane (higher pressure. Butane is 16,6 pounds at 70F, and isobutane is 30 psi at 70F), it was a bit better, but I think bottleneck is torch.
Buying propane torch is not an option, since propane is forbiddingly expensive or inconvenient. ($15 for non-rechargable 400 g cylinder? Fuck that, I can get 7x200g butane canisters... Yes, sure, I can get powerful propane torches that work with household propane bottles, but imagine carrying this piece of shit).