cob masonary heater

Discussion in 'Homesteading Questions' started by SpiritMountain, Dec 19, 2003.

  1. Would a cob masonary heater work? Only using cob as the mortar and local stone. Can anyone think of any advantages/disadvantages? Any help is greatly appreciated.
     
  2. Declan

    Declan Guest

    >Would a cob masonary heater work? Only using cob as the mortar and local >stone. Can anyone think of any advantages/disadvantages? Any help is greatly >appreciated.

    You ought to read a book called "Ken Kern's masonry stove" (You can read many of his articles in www.motherearthnews.com archives). It has detailed instructions on building several forms of low cost stoves as well as their history, woodlot management etc.
    In it, the shell of two stoves are made of slipformed concrete with vermiculite or several other heat storing fillers in the middle. The firebox and flues are lined with firebrick and refractory cement. Toward the end, he did write of intending to build clay stove with an inflatable ball used as a form to cast the firebox sphere.

    As for cob, it might work, atleast for a time, if you line the flues with firebrick. How'll the straw fare in high temperatures?
     

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  4. Thanks for your comments:
    I built a cob fireplace and the straw inside the cob stood up fine with the heat. I tore the fireplace down after about 9 months of using it in a log cabin. The straw inside where the fire was got burnt but inside the cob was not a problem. I dont build with concrete so my masonary heater would all be of cob and stone. Thanks again.

     
  5. Declan

    Declan Guest

    The temperature inside the firebox and flues ought to be very high to achieve complete combustion which is one of the advantages of a masonry stove. If the cob surface exposed to the fire doesn't crack/explode, the temperature isn't high enough.
    There is a reason why kachelofens of yore used arcane mixtures to line the flues and firebox.

    Besides, doesn't the straw have counterproductive insulative properties?