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Post by functional on Jan 22, 2015 13:08:54 GMT -8
I was reading a topic over on permies were Erik Wiser was said to believe that he may be achieving temps in the range stated. Unfortunately I don't have the bandwidth on my cellphone to watch all the videos I'd like, so I can't confirm this. Sounds particularly interesting to me because of my interest in smelting gold concentrates containing black sand, (iron alloyed with other metals and minerals).
While on the topic of high temperatures, I had noticed that there has been mention of using ceramic fiber insulation on the forum. Not an uncommon item for foundries and forges. But I've also noticed there's no mention of using refractory metal that is usually used with it? Usually its the hex form thats used in high heat applications with ceramic coating.
I know I've also seen mention of using ITC100 and ITC213, but not Satanite. I was hoping to try the ITC213, but I've seen mixed opinions of it. Maybe I just missed it.
My varied interests in this area are because I had two different applications in mind. One being a forge as mentioned above, (I like to gold pan). The other bring for a small tent or ice fishing heater, (I like being warm).
I'll go back to lurking now.
Keith.
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gjh42
Junior Member
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Post by gjh42 on Jan 22, 2015 15:40:05 GMT -8
Just looked up refractory metal, and find that most are extremely expensive and utterly impractical for ordinary use. Titanium is cheap enough to be cnsidered, but oxidizes above 600 C or so, thus would not be useable without protection from air. Tungsten costs something like $20-$50/pound, so is way too expensive for home use in bulk. What is practical for industry where its properties are needed to produce lots of income is not necessarily practical for a homeowner. If there is some source of these materials in a form useful to RMH builders, I am sure we would like to know about it.
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Post by functional on Jan 22, 2015 15:59:38 GMT -8
Just looked up refractory metal, and find that most are extremely expensive and utterly impractical for ordinary use. Titanium is cheap enough to be cnsidered, but oxidizes above 600 C or so, thus would not be useable without protection from air. Tungsten costs something like $20-$50/pound, so is way too expensive for home use in bulk. What is practical for industry where its properties are needed to produce lots of income is not necessarily practical for a homeowner. If there is some source of these materials in a form useful to RMH builders, I am sure we would like to know about it. I'm not sure who they get it from, but it's used by some of the makers of the backpack version of the rocket stove. Likely purchased in quantity or at least directly from suppliers on places like alibaba or aliexpress. Keith.
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gjh42
Junior Member
Posts: 61
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Post by gjh42 on Jan 22, 2015 16:45:08 GMT -8
Okay, backpack stove says that lightweight and small-scale use of materials is critical, so the cost of the bits needed for that use could be justified.
But really, there are very few places in a RMH where refractory metals would be more cost-effective over the long term than ceramic materials. I could see a P-channel plate made from it if it would resist warping and corrosion.
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Post by functional on Jan 22, 2015 17:58:40 GMT -8
Cost is something to be considered. But since there has been ceramic fiber insulation in use for at least one of the projects on this site, and considering the MSDS health concerns, both in handling and in relation to the airborne fibers, it would make sense to use the appropriate materials commonly used with it.
Personally, I may end up using these products and the health of myself and others in the area would be more of a concern than my wallet. If I had to chintz out due to monetary concerns, I wouldn't use ceramic fiber insulation at all. I'd cast a ceramic part to suit the situation.
Keith.
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Post by satamax on Jan 22, 2015 18:42:08 GMT -8
Well, regarding your title. en.wikipedia.org/wiki/Adiabatic_flame_temperatureWood can reach in the ideal conditions, some 3596F° no more. And that's under ideal conditions. I asked Peter what he thought about squeezing the last few degrees above the 1200C° 2192F°. The answer was, not without a fan.
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Post by photoman290 on Jan 23, 2015 4:23:31 GMT -8
Cost is something to be considered. But since there has been ceramic fiber insulation in use for at least one of the projects on this site, and considering the MSDS health concerns, both in handling and in relation to the airborne fibers, it would make sense to use the appropriate materials commonly used with it. Personally, I may end up using these products and the health of myself and others in the area would be more of a concern than my wallet. If I had to chintz out due to monetary concerns, I wouldn't use ceramic fiber insulation at all. I'd cast a ceramic part to suit the situation. Keith. not saying ceramric fibre is not toxic,but the MSDS is for occupational levels. in other words handling it 8 hours a day 5 days a week. wear a mask and seal it into the project and you should be ok.
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Post by functional on Jan 23, 2015 8:21:03 GMT -8
not saying ceramric fibre is not toxic,but the MSDS is for occupational levels. in other words handling it 8 hours a day 5 days a week. wear a mask and seal it into the project and you should be ok. Using it as a lining or as a heat riser, (for however many hours at a time), without a coating and having the fibers exposed to the updraft is effectively the same as handling it over that same time period. The only difference being that the fibers are going up the chimney into the surrounding area. You may be in a renote area without others to worry about, but people read this stuff and mimic what they perceive as safe proceedures, regardless of any warning or disclaimer. I can see I'm wasting my time here and on permies.
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Post by Daryl on Jan 23, 2015 8:34:41 GMT -8
I got some duraboard to use for a core and was shocked at how loose the particles were. I read about covering the board in some sort of wash or paste before use. I decided not to risk it and ditched the materials instead.
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Post by photoman290 on Jan 23, 2015 16:24:00 GMT -8
not saying ceramric fibre is not toxic,but the MSDS is for occupational levels. in other words handling it 8 hours a day 5 days a week. wear a mask and seal it into the project and you should be ok. Using it as a lining or as a heat riser, (for however many hours at a time), without a coating and having the fibers exposed to the updraft is effectively the same as handling it over that same time period. The only difference being that the fibers are going up the chimney into the surrounding area. You may be in a renote area without others to worry about, but people read this stuff and mimic what they perceive as safe proceedures, regardless of any warning or disclaimer. I can see I'm wasting my time here and on permies. who said anything about using ceramic fibre as a lining? it is normally used as insulation around a lining not as the lining its self. if it was used as the lining you would have a point.
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Post by satamax on Jan 24, 2015 3:47:47 GMT -8
Using it as a lining or as a heat riser, (for however many hours at a time), without a coating and having the fibers exposed to the updraft is effectively the same as handling it over that same time period. The only difference being that the fibers are going up the chimney into the surrounding area. You may be in a renote area without others to worry about, but people read this stuff and mimic what they perceive as safe proceedures, regardless of any warning or disclaimer. I can see I'm wasting my time here and on permies. who said anything about using ceramic fibre as a lining? it is normally used as insulation around a lining not as the lining its self. if it was used as the lining you would have a point. Peter's and Matt's ceramic heat risers! That's what gave the idea i think! IIRC, with heat, they become fibrous Inside.
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Post by ronyon on Jan 24, 2015 17:56:31 GMT -8
I haven't learned more about the ceramic fiber tubes, due to the cost/availability of them. Aren't they open to the flame? This could be a legit concern. Perlite in bucket stoves were brought up in the same context but I think perlite melts at rocket heat.
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