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Post by chupacabra on Sept 20, 2010 5:43:09 GMT -8
Hello every1!
I'm excited to have found this forum, so much info!!! I bought "the book" a few months back and have been collecting materials, it's starting to cool down over here in southern France and it's time to build this bad boy!!
The past couple of days I've been working on brick "J" and seem to have something that works...first try I just looked at the pretty pic's and go from there...no go...2nd try I used a measuring tape....amazing!!! I'm not to great with math as I'm a musician and can only count to 4, but the thing rips!!! After some reading I think I'll probably shorten the burn tunnel by 1 brick...[IMG_1564.jpg][/img]
I think I just put in a photo..
Anyways a few questions. Sorry if these answers are already somewhere in the forum...I've looked around and will be reading on here all day!
1) Has anyone used "flexible stove pipe" for the horizontal run? (it's about 10 euro's/meter cheaper...hence about 50 euro's saved if I can use it. Just not sure if it'll hold up with all that mass around it.
2) I've already built the vertical stack out of terra cotta flue bricks...Does the flue pipe need to go all the way to the top of the chimeney or could I run just a bit of pipe up in there and seal it off?
3) Is it ok to build the bench next to/touching a wall with sheetrock?
4)I am building on a cement floor.. I'm more interested in not stressing the floor with heat shock than using the floor as a collector...Would a little foundation of refractory cement be the best option?
5) For the heat riser and burn tunnel..I have a half a bag of "multi bat" Which is the"norm" over here for the flue brick's I put in(75%cement/25% lime), but I'm worried it won't hold up to the extreme temp's in the tunnel..I'm thinking refractory cement would be a better choice....I see that many have used clay, but I've never worked with cob or anything like that b4 and I'm a bit worried about messin' up!
Whew.....that's all for now! Back to reading on here....Also gonna try and find some good info on cob!
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Post by chupacabra on Sept 20, 2010 5:44:57 GMT -8
I can't figure out how to put more than 1 pic...sry.
This is a rough layout(obviously!) Above the 90 degree elbow is the exsisting flue.
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Post by chupacabra on Sept 20, 2010 5:47:16 GMT -8
Clay! So happy to have a farmer with a big tractor nearby!!!!
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Post by Donkey on Sept 20, 2010 8:42:16 GMT -8
Hello every1! I'm excited to have found this forum, so much info!!! I bought "the book" a few months back and have been collecting materials, it's starting to cool down over here in southern France and it's to build this bad boy!! Welcome. Not that I know of, though most anything will work. I haven't seen the stuff myself. What makes it flexible? If it's got pleats, they may cause friction in the system and slow things down.. Try it in test-land and see. I'm not sure I'm following this question.. Do you mean you've built the heat riser (the insulated bit inside the barrel) out of terra cotta or the chimney?? 'Cause the terra cotta can't handle the temperatures as a heat riser and WILL crack to bits. Otherwise, dunno.. Rephrase the question. Depends on whats behind the sheetrock. I'd give it a little gap. Umm.. Refractory will work, though it's a rather expensive option. I'm not sure what multi bat is.. Cement and lime can't handle the kinds of temps we see in rocket stoves. Natural clay soils tend to work well (though not always) and are a very forgiving medium. If you've got clay that can handle the heat, it's very hard to screw up. Once again, your best strategy is to build a mockup outside, somewhere safe, try a bunch of different things. When you get it right, move it inside. I've found that pearlite and clay slip work wonders together as an insulative refractory like material, though it can't handle much banging so you need to protect it from such things. |
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Post by chupacabra on Sept 20, 2010 11:23:44 GMT -8
Hi Donkey thanks for the quick response!
Just got done sifting a garbage can full of clay!
I haven't seen the stuff myself. What makes it flexible? If it's got pleats, they may cause friction in the system and slow things down..
Try it in test-land and see.
The stuff is kinda like a huge clothes dryer tube ,with pleats, and stainless steel. ..would love to try it in test land but dont wanna risk buying it and having it not work!
gonna spend the extra money....
I'm not sure I'm following this question.. Do you mean you've built the heat riser (the insulated bit inside the barrel) out of terra cotta or the chimney??
'Cause the terra cotta can't handle the temperatures as a heat riser and WILL crack to bits. Otherwise, dunno..
Rephrase the question.
Yes, that was a very poorly worded question!..sry...I was talking about the chiminey. which was put in for use with a wood stove, until I found out about the RMH. This chimney stack starts at the ceiling of the living space and runs out the roof approximately 11 ft long. here is a pic:
Question is, do I need to run the stove pipe all the way to the top of the chimney stack or could I just put about a foot's length up in there and seal it off?
Quote:
4)I am building on a cement floor.. I'm more interested in not stressing the floor with heat shock than using the floor as a collector...Would a little foundation of refractory cement be the best option?
Umm.. Refractory will work, though it's a rather expensive option.
tru, how 'bout some cob? And is there an easy/fast way to test the clay that I have? I was reading about the hockey puck test's and will give that a try tommorow. should they air dry or can I heat 'em up?
I'd love to not use any cement!
Gonna go read some more threads!!
Thx again!
p.s. can't seem to get that qoute thingy right..!?!
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Post by giggles on Sept 20, 2010 13:00:11 GMT -8
planning my first rocket stove aswell  wen the gases come over the riser and down the inside of the barrel.... what is the setup for the connection from inside of barrel wall to flue? and does the lenght of the burn tunnel have a big bearing? if so whats the optium lenght? great forum by the way |
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hpmer
Full Member
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Post by hpmer on Sept 20, 2010 13:23:26 GMT -8
does the lenght of the burn tunnel have a big bearing? if so whats the optium lenght? The way I understand it, the shorter the better, but knowing that it has to be something to account for the barrel surrounding the fuel box and that surrounding the heat riser. I think the better answer is how it relates to the heat riser and the minimum standard is the heat riser should be at least twice as high as the burn tunnel is long, though even more is better. |
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Post by canyon on Sept 21, 2010 8:27:05 GMT -8
Hello every1! . 2) I've already built the vertical stack out of terra cotta flue bricks...Does the flue pipe need to go all the way to the top of the chimeney or could I run just a bit of pipe up in there and seal it off? 3) Is it ok to build the bench next to/touching a wall with sheetrock? 4)I am building on a cement floor.. I'm more interested in not stressing the floor with heat shock than using the floor as a collector...Would a little foundation of refractory cement be the best option? 2) just get your flue pipe inside the existing flue and seal it off well. Think about what you do as to how it affects cleaning/maintenance. 3)I built mine with a three inch gap between mass/sheetrock that I filled with clay/perlite. Highly recommend the stuff (vermiculite will work too or perhaps expanded fired clay((Leka??)) that you can get in Europe but not in the states yet) Then your finnish plaster can cover it all the way to the wall. 4) A foundation of clay sand mortar and then at least 5 inches of mass before the embedded flue won't shock your concrete but your slab will draw some heat away unless you do some insulating with the stuff mentioned above. Keep up the good work and keep us posted! |
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Post by chupacabra on Sept 21, 2010 11:23:59 GMT -8
Thanks Canyon!
QOUTE
2) just get your flue pipe inside the existing flue and seal it off well. Think about what you do as to how it affects cleaning/maintenance.
Exactly, my worries!! I'm pretty sure I can get it sealed off, but I'm worried about cleaning.....I'd rather not have to get up on the roof if I don't need to!!..
Also, were at 2,100 ft above see level (humid) and I'm a bit worried about condensation dripping down the terra cotta and onto whatever I use to seal.
any idea's are greatly appreciated!
Qoute
3)I built mine with a three inch gap between mass/sheetrock that I filled with clay/perlite. Highly recommend the stuff (vermiculite will work too or perhaps expanded fired clay((Leka??)) that you can get in Europe but not in the states yet) Then your finnish plaster can cover it all the way to the wall.
Thanks! How'd ya keep the gap? just by molding it with your hand? yes i'm a rookie!!! Gonna keep an eye out for some Leka!
Qoute
4) A foundation of clay sand mortar and then at least 5 inches of mass before the embedded flue won't shock your concrete but your slab will draw some heat away unless you do some insulating with the stuff mentioned above.
Man that's thick!! gonna give it a shot, once I find a good clay/sand mix!
I just spent the day playing with clay slip, sand...gonna try and find some perlite tommorrow...I've already seen vermiculite at the stores and hopefully will be able to find some perlite...
It's seems as though the 2 (verm/perlite) are fairly similar, but most people on here seem to prefer perlite...
I made a few different puck's 1 clay/1 sand 1 clay/2 sand...etc.. will post pics when they're dry...also tried a few mix's with some ground up/chopped up sunflower stalk's that we used to insulate our wall's...dont think I'm gonna get that stuff to close to the heat! We have a huge sack leftover and would like to use it for mass..
Also I had fun burning paint off the barrels today! I got an old water heater for insulationg the heat riser, I thought I could just slide the outer cover off after cutting both end's hahaa haaa....nada....I then realized I need to cut the dang thing down the seam to correct diameter and pealed it off...
How does one go about hooking/wraping the thing around the heat riser so it stay's? I had rivet's flash through my mind, but quickly saw them melting meeelllting away... how 'bout just wrapin it around the heat riser and putting some clay/sand morter on the seam? sry if this has already been covered...when I'm not workin on this bad boy or diggin up potatoes, I'm reading up!
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Post by canyon on Sept 22, 2010 8:46:28 GMT -8
Thanks Canyon! QOUTE Thanks! How'd ya keep the gap? just by molding it with your hand? yes i'm a rookie!!! Gonna keep an eye out for some Leka! Qoute To keep the gap I just molded/packed the perlite/clay against the wall by hand or with a slip form(a piece of sheet metal or plywood) as I went and then packed the cob etc right up against it. |
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Post by Donkey on Sept 22, 2010 9:24:36 GMT -8
You could also make a bunch of adobe bricks, quick stack 'em and fill behind..
I've been using adobes more and more for this kind of thing. They make for fast building of benches, chambers, this and that, here and there.
I make 'em in my spare time and days off and let 'em sit.. Stack 'em up and when I need 'em, there's usually a great stack of 'em waiting for me..
Though I just emptied my reserve and need to start making more.. With winter coming on..
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Post by chupacabra on Sept 23, 2010 14:15:37 GMT -8
Yeah u right! I need to build me a brick mold to get that goin on..It seems as the clay/dirt we have is pretty darn nice!
The puck's (see photo) have dryed and are all pretty solid! I did mixes of(right to left) 1/1:clay/sand, 1/2,1/3 , etc...they all seem to be pretty tough and no crack's! I guess I'll go with the 1/1 ratio, whadda y'all think? Also, behind 1/2 and 1/3's are some(adobe?) where I added 1 part chopped up sunflower stalks..what's next? I was thinkin' a round of disc golf and see which one last's the longest? No seriously, should I heat 'em up now?
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Post by chupacabra on Sept 23, 2010 14:26:31 GMT -8
Here's a pic from today, I spent a long time gettin' the hot water heater shell cut/hooked to the right diameter, I will restate what many before me have already said. "wear glove's" haha, after all my messin around, I finally got it cut out and around the heat riser and got the barrel on there only to realize I have 2 1/2" "gap instead of 2  every thing seems to be runnin smooth...Is this gonna be a serious problem down the line? Gonna work on the exit chamber and try and hook up some flue pipes tommorrow, and see what happens! |
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Post by Donkey on Sept 23, 2010 20:11:10 GMT -8
'Bout yer pucks.. I can't tell how big they are.. Sounds like your clay is a lot like mine.
Bigger test pieces will tell you more. Try a 1/1 mix that's a foot on a side and see how it goes.. Will it crack? In the mean time, get those pucks in the heat as soon as their dry.
A bigger gap is fine. I recommend larger gap size around the heat riser (especially above) than the book suggests.
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Post by chupacabra on Sept 23, 2010 23:24:16 GMT -8
Thanks Donkey, That's great news for the gap! I had already read on here that y'all prefer a bit higher than the book, and that gap(above the heat riser) is at approx 3 ". Bad news, it rained last night, and the puck's were outside!  grrrrrr....I am really good at learning the hard way!! The puck's were about the size of a really big hamburger. I'm gonna try and build a brick mold today..I've seen pic's of your's, gonna try and replicate it! Not sure if I'll get to hookin up the flue pipe today as it's lookin pretty nasty out. Once again, thank for all the help and knowledge ;D ! |
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every thing seems to be runnin smooth...Is this gonna be a serious problem down the line? Gonna work on the exit chamber and try and hook up some flue pipes tommorrow, and see what happens!
grrrrrr....I am really good at learning the hard way!! The puck's were about the size of a really big hamburger. I'm gonna try and build a brick mold today..I've seen pic's of your's, gonna try and replicate it! Not sure if I'll get to hookin up the flue pipe today as it's lookin pretty nasty out. Once again, thank for all the help and knowledge ;D !