• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies living kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education experiences global resources the cider press projects digital market permies.com all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • raven ranson
stewards:
  • paul wheaton
  • Jocelyn Campbell
  • Julia Winter
garden masters:
  • Anne Miller
  • Pearl Sutton
  • thomas rubino
  • Bill Crim
  • Kim Goodwin
  • Joylynn Hardesty
gardeners:
  • Amit Enventres
  • Mike Jay
  • Dan Boone

J tube  RSS feed

 
Posts: 9
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
We are building the rocket mass heater core with fire brick. The bricks will be mudded with clay or furnace cement. What is the best way to insulate the J tube? Should we allow for heat expansion between the J tube and the cob? If so would ceramic fiber blanket suffice for both?
Thanks to all for their guidance
Bob
 
gardener
Posts: 2596
Location: Upstate NY, zone 5
93
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Ceramic fiber blanket is ideal for insulating the J-tube and heat riser. That would as you mention avoid any expansion issues as well. You would want some sort of insulating material in any case, and they tend to be softer or at least weaker and more forgiving.
I'm not sure space between the firebricks and a cob layer would be necessary, though if the cob were thinnish and served as the finished surface a tiny gap would reduce shrinkage and heat expansion cracks.
 
Just the other day, I was thinking ... about this tiny ad:
177 hours of video: the 2017 Permaculture Design Course and Appropriate Technology Course
https://permies.com/wiki/65386/hours-video-Permaculture-Design-Technology
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!