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tom b atkinson (Tomjax)
| | Posted on Tuesday, February 26, 2002 - 10:01 am:
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I have a Japanese # 5 kamado and it sems to be made of clay.
Is the recent textured model described as tera cota a ceramic material like the regular kamado or is this 2 different things?
Is the textured ones fragile as they would seem to be or are they as durable as the ceramic ones?
Help with my kamado 101 lesson, Richard. |
Richard J (Richardj)
| | Posted on Tuesday, February 26, 2002 - 12:16 pm:
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Tom,
The ceramic body of the Textured Kamados is made of the exact same formula as the Mosaic or Custom tiled Kamados. The exterior surface is the only thing that is different.
I made the Japanese Kamados from a clay found in and around the rice patties. They were fired under 1000 degrees (just to vitrify or go into a ceramic bond)and were very fragile, as you know. The clay could expand and contract with the change of temperature fairly well if baking temperatures were not exceeded.
Both the fragility and the need for higher refractory temperature capabilities have been corrected with our present Kamados. The walls are much thicker and stronger (modus of rupture) and the ceramic formula is entirely different than the earlier Japanese or copies of these Kamados.
Picture shows the wall thickness of #7 Kamado Gas hole plug (approximately 2 inches thick) and a BGE copy of my earlier #5 Japanese Kamado (approximately ¾ inch).
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Mark Motta (Mark)
| | Posted on Wednesday, February 27, 2002 - 6:49 am:
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Wow! That's the first time we've seen a side-by-side comparison. It really is compelling. |
djm5x9 (Djm5x9)
| | Posted on Wednesday, February 27, 2002 - 1:28 pm:
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Mark:
Kinda precludes the need for fire bricks . . . |
Richard J (Richardj)
| | Posted on Wednesday, February 27, 2002 - 1:52 pm:
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Mark, I did an temperature graph for our earlier Meridian stove where we did extensive testing at UL showing the so-called “R” factor (the rate heat transfers through our refractory ceramic material). The curve showing the wall thickness vs. heat transfer is quite remarkable. Starting at 1/4-inch wall thickness the curve goes up at an approximent 80-degree steep angle, showing a very high heat transfer or conductivity. At 3/4-inch wall thickness (the walls my earlier Japanese Kamados and the BGE) there was about 70-degree angle or much better (less transfer)but still at a very steep angle. After 1-1/2 inch wall thickness there was a much less of an angle (approximately 30 degrees) indicating still much less of a heat transfer. Most important, we found that after 2 inch wall there was very little curve and very little benefit to have the wall thicker than 1 ½ to 2 inches.
Our goal is to have the temperature remain inside the Kamado and not dissipate though the walls. The material of the walls is, of course, very important when considering the “R” factor, with steel being the worse. Ceramic is one of the best insolating material and the Kamados wall of over 1-½ inches is the optimum thickness.
There is the additional advantage of thick walls and that is the benefit derived from “thermal mass.” We all know how nice it is to have this uniform and unique heat retention characteristic.
I have always stated that we would love it if our Kamados weighed 30 pounds, but then they wouldn’t work right. I hope you agree that the extra expense and torture in getting your heavy Kamados to their home was well worth it in the long run. |
Louis Cohen (Louiscohen)
| | Posted on Wednesday, February 27, 2002 - 4:47 pm:
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Thanks for a nice clear explanation. |
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Textured same material as ceramic?