[Cob] Rocket Stove

[Shannon Dealy]

On Sat, 6 Oct 2007, michael montagne wrote:

> So I look at pictures and diagrams of rocket stoves and I read how they work
> and where to clean what when but a question still remains.  Are these 55
> gallon steel drum heat exchanger containers just upside down barrels?  In

Yes, they are just upside down barrels

> other words, is it necessary to open the top for maintenance?  If not, why
> don't more people just substitute cob for the steel barrel?

  1 - The barrels provide alot of immediate heat to the room, where the
      bench provides less heat and has a significant heat lag.

  2 - Cob directly over the top of the heat riser would almost certainly
      crack and allow exhaust gases into the room which would not be safe.

  3 - In some cases where immediate heat is not necessary, people have
      completely cobbed over the outside of the barrel.

>  I guess that's
> really more than one question.  Also, where to source the smaller barrel for
> the feed tube?  I'm in Portland, Oregon.  My stove will be outside, heating
> a small covered area of my deck to allow use during the cooler months.

The small barrels for the feed tube are getting harder to come by in the 
USA, but you could check scrap metal yards.  The feed tube barrel is not 
strictly necessary as it is not sealing part of the system the way the 
other barrel does.  I have done a variety of alternatives at different 
locations depending on the materials available:

    - Just plain brick work

    - Bricks wrapped in cob

    - Bricks wrapped in insulation and cob

    - Bricks in a sheetmetal tube (scrap metal roofing) wrapped in cob

    - Just cob (doesn't hold up well, feeding sticks in tends to break it
      down over time)

FWIW.

Shannon C. Dealy      |               DeaTech Research Inc.
dealy at deatech.com     |          - Custom Software Development -
                       |    Embedded Systems, Real-time, Device Drivers
Phone: (800) 467-5820 | Networking, Scientific & Engineering Applications
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