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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Dear François<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The best answer I have found so far is that sand needs to be graded to a narrow size range in order to have insulation properties. What you want you avoid is having lots of little particles to filling the spaces between larger ones. It depends on where you are when looking to such sand. If you are in a place near a windy beach, that would be the place to get single sizes. In Northern Mozambique there are lots of sand dunes and they contain almost only one size! Even though there is unlimited sand, it is hard to make concrete products because of that issue.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>You can buy two round brass sieves from a soils laboratory supplier, for example 1.15mm and 2.0mm. Throw out everything larger than 2.0 and use everything sitting on the 1.15mm screen. That will have much less heat conduction that the original (mixed) sand.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Remember that even when compacted, it will have no strength at all. Zero.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0mm 0mm 0mm'><p class=MsoNormal><span style='color:#1F497D'>++++++++</span><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif";mso-fareast-language:EN-CA'><o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=FR>Hello everyone,<o:p></o:p></span></p><p class=MsoNormal><span lang=FR><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>I am currently trying to build a wood saving stove (rocket stove model). All the info I gathered are saying to use wood-ash as an insulator between the outside layer of sheet metal and the L-shaped combustion chamber.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Do you know if I could replace wood-ash by anything else ? Something easy to come by… Something like dry sand for instance ?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Thanks!<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>François<o:p></o:p></span></p></div></body></html>