• 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 skip experiences global resources 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
  • Anne Miller
  • Pearl Sutton
  • Mike Haasl
stewards:
  • paul wheaton
  • Joylynn Hardesty
  • Dave Burton
master gardeners:
  • jordan barton
  • Greg Martin
  • Steve Thorn
gardeners:
  • Carla Burke
  • Jay Angler
  • Kate Downham

shippable cores - could CO2 sand be the answer?

 
Mother Tree
Posts: 11640
Location: Portugal
2237
dog duck forest garden tiny house books wofati bike bee solar rocket stoves greening the desert
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I was talking with a friend of mine yesterday about rocket mass heaters, and showed him some links and videos.  And he immediately said 'Why don't they cast that bottom bit out of CO2 sand?'  I explained that various attempts have been made to cast the core out of various things, mostly without long-term success, but that I'd never heard of CO2 sand.

Apparently it's used in making molds for casting engine parts and can take some very high temperatures.  It's also being used as a building material in disaster relief areas.  

I've collected a few videos and links and just dumped them here for brainstorming purposes.











https://en.wikipedia.org/wiki/Sand_casting

http://www.industrialmetalcastings.com/casting_co2_molding.html

http://inhabitat.com/new-co2-sand-bricks-are-2-5-times-stronger-than-concrete/

https://a3511.wordpress.com/2016/11/17/co2-sand-bricks/
 
pollinator
Posts: 272
Location: Worcestershire, England
55
hugelkultur purity forest garden fungi trees urban bike bee woodworking
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I think the answer is in the forth video after the casting the chap pokes near the pattern and it falls apart. In the second video it is "hard as brick" but they are using epoxy to stick the sand because hard things tend to break easily as they are not ductile. The ductility here comes from the epoxy which I would think would combust in the rocket mass heater. If you could replace that with some else like a e.g high temperature silicone? maybe it would work.

Interesting videos though.

 
Where does a nanny get ground to air missles? Protect this tiny ad:
Greenhouse of the Future ebook - now free for a while
https://permies.com/goodies/greenhouse
reply
    Bookmark Topic Watch Topic
  • New Topic