Win a copy of For the Love of Paw Paws this week in the Fruit Trees forum!
  • 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
  • Anne Miller
  • paul wheaton
stewards:
  • Jocelyn Campbell
  • Mike Jay Haasl
  • Burra Maluca
garden masters:
  • James Freyr
  • Joylynn Hardesty
  • Steve Thorn
  • Greg Martin
gardeners:
  • Carla Burke
  • Dave Burton
  • Pearl Sutton

Burn Tunnel and Riser cast as one

 
Posts: 3
Location: Zone 5a (I think) Kawartha's Ontario Canada
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have a chance of casting a 6 inch burn tunnel and riser as one complete casting. I wanted to use cardboard tube, suspended in a wooden box or crate former. I believe that I can get a good quality cast product out of this one use pattern. Once set I will fire it to burn out the cardboard. My concerns are, will a 6 inch round burn tunnel work, and how long should it be ? I will use a vibrating table to make sure all the air is out of the cast. The end product should be a large square L shape with a nice clean 6 inch bore running through it. Could this work?
Thanks
 
Posts: 135
Location: Springdale, WA USA - Cold Mediterranean Climate
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
What material are you casting it out of?
 
gardener
Posts: 3086
Location: Southern alps, on the French side of the french /italian border 5000ft elevation
135
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Simon, dunno about clay based materials.

But with castable refractory and ciment fondu, you should leave expansion joints.
 
gardener
Posts: 791
Location: Tonasket washington
44
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Make the interior of the Burn tunnel and heat riser rough. the rough of the bricks and the brick edges contribute to good mixing. and if you are using cast-able refractory make sure its high heat alumna.
 
Posts: 61
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
If it were up to me I'd cast the burn tunnel and the heat riser separately. The expansion and contraction cycles are going to make some cracks in the joint of the "L"

You could "key" the two pieces so they sit into each other and have some room for uneven expansion rates due to size and distance from heat (not form material differences, we know that would be all made from the same thing).

The effort to make a squarish burn tunnel is not that hard or at least a square joint in your "L" for more turbulence.

I want to see some pictures when you get started, thanks -Dan.
 
These are not the droids you are looking for. Perhaps I can interest you in a tiny ad?
A rocket mass heater is the most sustainable way to heat a conventional home
http://woodheat.net
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!