• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • paul wheaton
  • Anne Miller
  • Mike Jay
stewards:
  • Jocelyn Campbell
  • Burra Maluca
  • Devaka Cooray
garden masters:
  • Dave Burton
  • James Freyr
  • Mike Barkley
gardeners:
  • Joylynn Hardesty
  • Greg Martin
  • Pearl Sutton

Help understanding rocket oven j-tube  RSS feed

 
gardener
Posts: 1546
Location: Olympia, WA - Zone 8a/b
548
bike books forest garden fungi homestead hugelkultur kids trees
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello all,

I'm a novice when it comes to rocket ovens but I would like to build the one that is shown in Paul's rocket oven documentary sometime in the future. The dvd is great but I'm having a bit of trouble with the j-tube.

First, am I getting the basic vocabulary correct? Is it called a j-tube? Is it a batch box too? What exactly does that refer to and what is the alternative?

Also, is the base called the burn tunnel and then the part going up called a heat riser?

My understanding is that it can be built to different dimensions. I have seen threads talking about 4", 6" and 8". What exactly is being measured for those? Is it the open part on the inside?

Say you go with a 6" system. How does that affect the dimensions of the rest of the system? Is there a certain minimum height for the heat riser? How about a maximum height?

As far as building the j-tube. I have seen a couple different versions. Some seem portable and some do not. One looked like it used duraboard on the inside and then some sort of bricks on the outside of the duraboard. Do those bricks have to be fire bricks? Or would regular masonry bricks work?

Are there any basic schematics available for free online anywhere? Even hand drawn would help a lot for me to understand exactly how it is all built. Also, if there are any good YouTube videos that show the construction of a j-tube that is similar to the one used in the documentary that would be helpful too.

Really appreciate any help you all can give with this.
 
Posts: 414
Location: Wellington, New Zealand
12
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
There's a basic glossary here http://donkey32.proboards.com/thread/732/glossary-terms

The inch refers to the diameter of a theoretical circular riser where secondary combustion occurs. If you use a square riser, or octagonal riser, it's the diameter of a cylinder that fits inside.
 
The first person to drink cow's milk. That started off as a dare from this tiny ad:
It's like binging on 7 seasons of your favorite netflix permaculture show
http://permaculture-design-course.com/
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!