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Post by Dan (Upstate NY, USA) on Jan 2, 2012 2:01:02 GMT -8
What do you think would last longer as the burn tunnel ceiling?
3/4" (1.9cm) by 11" (28cm) by 10" (25.5cm) steel
or
12" (30.5cm) by 11" (28cm) by 3" (7.62cm) fire brick.
I have both which one do you think I should use???
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Post by pasto76 on Jan 2, 2012 7:52:08 GMT -8
not knowing as much as others, I would use the brick because it wont oxidize away like steel eventually will. However, 3/4 is some pretty serious plate, I bet that would last a while.
there is also some comments, somewhere in all the threads of rocket stoves, about steel not providing enough friction and turbulence.
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Post by josephjcole on Jan 2, 2012 8:07:54 GMT -8
Assuming you are going to cob over all of this then I would go with brick. Steel expands and contracts quite a bit more than brick or cob during heating and cooling. Of course it also depends on what you are insulating the burn tunnel with. Insulation can act as a good expansion joint. How's that for a vague answer?  Joe |
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Post by Donkey on Jan 2, 2012 10:27:13 GMT -8
There's a lot of oxygen in that area..
My bet is on the brick.
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ronk
New Member
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Post by ronk on Mar 9, 2012 23:01:48 GMT -8
I am thinking what would be good burn tunnel ceiling for my sauna project (inspired by Donkey's work ). If possible i would love to have steam (throw water at burn tunnel ceiling) possibility too. Then again water against barrel bottom would mean really short lifespan. Has anyone else tackled into this and how did you solve it? The lava rock that Donkey used in his sauna project would most probably be too costly for me and i doubt you can get steam with it as its more mass than instant high heat i guess. |
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Post by canyon on Mar 10, 2012 8:05:18 GMT -8
If you doubt that you can get steam off of hot rocks then lucky for you, you have some sauna experience to gain! Hot rocks are much preferable to hot steel in a sauna and provide lots of hot steam after being charged. We don't have a lot of local rocks where I live that can handle the stresses but the white (with a peppered black) ones can. Living near the ocean, we have many rocks to choose from. You don't want most river rocks that contain moisture as they will explode. The old timer trick is to build a campfire and then put the prospective sauna rocks in and get out of the way. The ones that survive many hot fire hours without exploding are good the others show they aren't up to it. Beware, this method is dangerous, wear priotective gear and keep anyone else without the gear away.  |
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ronk
New Member
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Post by ronk on Mar 10, 2012 8:22:53 GMT -8
;D My bad, i should have stated that i am coming from fenno-ugri culture so i'v had tons of all sorts of sauna experience since year 0 . How the modern sauna stove looks here is that ceiling is say 5mm steel and on top of it you have your fist/two fist size granite stones. I guess american iron stoves are somewhat similar to those (without the rocks on top ofcourse) - so the burn temperatures are already lower and also its more durable than few mm barrel bottom. However, i feel the bottom of barrel would not last long having near 1000C flame hitting it, rocks on top and splashes of water as bonus. If the ceiling would be made of firebrick in arch - i have my doubts on the steam temp you will get out of those and also the excessive cracking due to high flame temp from below and water on top. The only 'moderatly cheap' rocket stove method i can think of is replace bottom of barrel with 5mm or metal sheet and have it rest on barrel sides+additonal cob support. |
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Post by canyon on Mar 10, 2012 9:15:18 GMT -8
Well, the place to harvest the heat for the rocks etc. is after the heat riser anyway, you want the burn tunnel to be insulated. For a cheap rocket sauna fired once or twice a week I'd pile the stones on top/sides of the barrel and not worry about how long the barrel lasts and replace it in a few seasons when it needs it. I've seen red hot barrel stove saunas go years with rocks on top and water applied liberally for steam every time. The question I have is what are you going to do with the heat left over after the barrel? Mass bench? |
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ronk
New Member
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Post by ronk on Mar 10, 2012 10:25:28 GMT -8
Yeah... well i guess it wouldn't hurt to try out the barrel and consider something longer lasting once its dead. Thanks for advice. The floor plan is 3.3m circle, i initially thought of moving the exhaust through the cob bench in both sides but as the feed tube is next to door and exhaust coming from opposite side it will be too messy - the exit to outside air would end up same side as door and this wouldn't look too nice. So... current plan is something like that:
______________
/ bench b\
/ e\
d n I
o feed-barrel-exhaust
o c I
r h I
\ /
\__bench_______/
PS lucky-funny-dangerous story that happened on a hike where we built sweat lodge. As we had the best rocks we could find (read: not so good) in the fire and everyone sitting by the fire, we played some game where one has to fight for the 'best' position around the fire. During shift two guys started argumenting who should be sitting at certain spot neither one accepting it. Suddenly one of the rocks exploded real loud and bad, spitting hot sharpnel all over the empty spot that those two were arguing about  |
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Post by stovol on Apr 10, 2012 21:14:56 GMT -8
Coat the steel with itc 213 I believe is the correct number or hi e 840 m and it will last a very long time
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Post by Rinchen on Apr 11, 2012 2:53:11 GMT -8
Coating metal is interesting. Do you think it could be done with some other means? Like using fireclay for instance?
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