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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><div><div><div><div><div><div><div><div><div><div><div><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Dear Part-Casters<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Julien’s casting moulds are good examples of how to make castable refractory parts. I am sharing some photos of how a perforated conical ceramic combustion chamber was created using a similar method. It may inspire someone. The refractory materials are the very low thermal expansion type so cracking in use is not a hazard. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Cast wax into cylinders or cones using a plastic mould with holes drilled in it.<o:p></o:p></span></p><p class=MsoNormal><img width=151 height=254 id="Picture_x0020_1" src="cid:image003.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>That is green nylon.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Push the cores out with the metal tool.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Prepare hot wax, the combustion chamber mould and the cylinders, one for each hole.<o:p></o:p></span></p><p class=MsoNormal><img width=302 height=394 id="Picture_x0020_5" src="cid:image005.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Dip the cylinders into the hot wax and stick them on the mould one by one.<o:p></o:p></span></p><p class=MsoNormal><img width=151 height=157 id="Picture_x0020_6" src="cid:image007.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><img width=151 height=140 id="Picture_x0020_7" src="cid:image017.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Put the castable mix on and through everything.<o:p></o:p></span></p><p class=MsoNormal><img width=151 height=131 id="Picture_x0020_8" src="cid:image018.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Break off the extra length.<o:p></o:p></span></p><p class=MsoNormal><img width=189 height=179 id="Picture_x0020_2" src="cid:image019.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Upper side where the fuel will burn<o:p></o:p></span></p><p class=MsoNormal><img width=189 height=191 id="Picture_x0020_3" src="cid:image020.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Mount it in the stove<o:p></o:p></span></p><p class=MsoNormal><img width=189 height=226 id="Picture_x0020_4" src="cid:image016.png@01D15911.D6F52080"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Light a small fire to melt out the wax<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Or… melt the wax away like this:<o:p></o:p></span></p><p class=MsoNormal><img width=151 height=211 id="Picture_x0020_9" src="cid:image021.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Finished part: a one-off ceramic part with a complex structure<o:p></o:p></span></p><p class=MsoNormal><img width=151 height=145 id="Picture_x0020_10" src="cid:image022.jpg@01D15913.1DFE70C0"><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Clean up the holes. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>This is the very first POCA grate. The later ones had no outer ring of holes, instead having the secondary air blow horizontally over the lip which reduced the flame height. The centre hole (20mm) and the 12 clustered around it (13mm) were retained.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>After making a prototype and showing the performance, the production was done using a low-expansion clay mix containing several additives.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Crispin<o:p></o:p></span></p></div></div></div></div></div></div></div></div></div></div></div></div></div></body></html>