I built some Mikey burners a few years ago. Back then the book was only $20.00 so I bought it. I also have a pdf copy on my phone for quick reference.
Attachment 43620 Attachment 43621 Attachment 43622 Attachment 43623 They go from the smallest made from a ballpoint pen for the nozzle to the large ones using mig nozzles and parts turned on the lathe. The big one is blowing into the end of a fire extinguisher and melting glass inside. It also heats the shop to 90° in just a few minutes from near freezing. With a stack of fire brick, it gets steel up to forging temperature.