I'm interested in building a J-Tube Rocket like the ones that appear to be in use at
Wheaton Labs (pictures attached). The one on the left in the picture heats the
shower water, and the one on the right seems to get used frequently for boiling pots of water and cooking rice for
PEP BBs. Both look like very similar designs. One has a longer burn tube and taller heat riser. It looks like the
water heater one was later modified to have a taller
feed tube and heat riser to reduce sooting. I have several motivations to build one: a)
to learn how to build one by building one from scratch, b) to have one on hand to earn some rocket related BBs, and c) to use to boil Big Leaf Maple sap to make syrup. Currently I use a combination of a propane crab cooker and my
wood stove to make Big Leaf Maple syrup, so it would
be nice to replace the propane crab cooker with a J-Tube rocket. I boil the sap in a stainless steel catering pan that is 13 inches wide by 21 inches long by 6 inches deep (picture attached). Large quantities I boil outside, smaller quantities I bring inside if the inside humidity is low. I would likely modify the top of the heat riser to better accommodate the catering pan so that it doesn't just scorch the sugar in the center of the pan.
For some reason, I particularly like the design of the pictured rockets. I already have angle iron and welding capabilities, but I'm curious to know:
1) do folks familiar with J-Tube designs like this design? What are the pros/cons?
2) what materials were used (other than the angle iron)
3) what are the actual dimensions of those J-tubes
4) is there someplace
online where the materials can be purchased (Amazon?) Has anyone already put together a shopping list with links to where each item can be purchased?
5) which of the two pictured rockets would you recommend for my application - shorter burn tunnel or longer and why? (for boiling sap)
The pictures attached are from the
2019 ATC Thread. I've searched extensively and haven't found any Permies Forum threads specifically about the construction of these two J-Tube rockets, so if those exist please link me to those threads.
Thanks in advance J-tubers!