nemo
New Member
Posts: 48
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Post by nemo on Dec 20, 2014 12:32:32 GMT -8
Thank you,Max! I meant the exit hole from the first bell, can it be anywhere around the bottom of the barrel? I only have space for the J and there is a wall behind the barell so I thought going left or right with the half barrels(the exit from the first bell, the mass).
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nemo
New Member
Posts: 48
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Post by nemo on Dec 20, 2014 13:18:49 GMT -8
Also, tomorrow I ll start preparing some casting material and did not know any cheap receipe. I did post a thread about it on the materials section but as i see you guys are helping me prety fast, I thought i'd also let you know about that.
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Post by shilo on Dec 20, 2014 14:33:00 GMT -8
Thank you,Max! I meant the exit hole from the first bell, can it be anywhere around the bottom of the barrel? I only have space for the J and there is a wall behind the barell so I thought going left or right with the half barrels(the exit from the first bell, the mass). no problem. any angle is OK keep a large manifold
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nemo
New Member
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Post by nemo on Dec 20, 2014 14:43:02 GMT -8
Thanx,shilo!
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Post by satamax on Dec 20, 2014 14:58:04 GMT -8
Make a drawing first, so we know what you want to do exactly. That could avoid some mistakes.
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nemo
New Member
Posts: 48
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Post by nemo on Dec 26, 2014 8:53:13 GMT -8
Hey guys! I've been working on my stove. and it looks pretty good so far, I will be posting photos later after all is done. Pretty excited about the stove. Sata, no need for drawing, i got it clarified, thank you! Still I have few questions an thought of posting them here. 1. Can I use a chimney damper for after the fire is out in order to stop cold air coming back the chimney and cooling the thermal mass? 2. If I make a higher heat riser, say a barrel and half or two barrels one on top of the other, will that improve the performance of the stove? The proportions remain the same in that case? Meaning burn chamber half of the riser and the feed 1/3. 3. I feel the stove is not as good as It should. The wood is burning up high, there are big chunks of burning coal instead of just ash. Maybe it's because of the small space between riser and barrel, the ring that is. It's only about 3cm on this. I'm kind of limited because the riser is made of bricks plus insulation...If this the case , I 'll find ways of making the space larger.(use thinner bricks,ceramic blanket).
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Post by satamax on Dec 26, 2014 9:05:59 GMT -8
Nemo, using a damper is not too foolproof. Just put a piece of brick or something on the feed tube to close it. Plus you will have bells, so they trap heat more than a flue.
Insulate your feed tube and burn tunnel if you don't want badly burned pieces of wood.
Is your 3cm problem top gap, or side gap? If it's 3cm top gap, that's nooooooooo goooooood! If you're not planing to cook on top of your barrel, raise it a third of a barrel or more, but leaving the heat riser as it is for the moment. Tho, proportions can remain the same if you increase the height of the heat riser. To me that's no problem.
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nemo
New Member
Posts: 48
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Post by nemo on Dec 26, 2014 12:09:50 GMT -8
It's a side gap. Top gap is 5-6cm. Side is more from 1 to 3 cm..not same all around. So I can rise another barrel without having to change other proportions?
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Post by satamax on Dec 26, 2014 13:51:25 GMT -8
If it was 3cm all over, may be you could have goten by. But uneven, 1cm to 3cm sounds bad! Time to take that barrel off and rebuild!
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nemo
New Member
Posts: 48
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Post by nemo on Jan 1, 2015 13:59:41 GMT -8
Rocket running pretty smooth! Thank you guys! I got to the finishing part. Paints, oils. One thing though is still bugging me. After some 5-8 hours of running, the coal builds up and wood is burning also upwards.... It's got good draft now, and with some bricks covering the top I don't have problems with smokeback . I understand, Max ,that this is due to the feed chamber getting very hot. I did insulate it but it still gets hot after a while....I will add more cob...I also added some glass wool dipped in clay slip. Ceramic fibre is hard to get and expensive. About 15-20$/m. I recognise that I cannot understand the principle in insulating the feed. The bricks still get hot on the inside, and with insulation they do not pass the heat further.. to another brick or cob. Without insulation and with cob takes more time to cool, but also heats up harder. With insulation It heats faster and cools faster. Right?
About the last retouches, I got some paint for the barrels that is good up to 150 degrees Celsius. Will that be good to paint the barrel with. I do not have that thermometer thingy I saw often sticked to the barrel. I'd like one but do not know where to get it from. Also no temperature reader. I can tell you only that water boils when touching the surface and that the metal of the barrel got from silver to almost entirely black after 72hours of continuous burning.
And another question, about linseed oil on cob to give it the shiny look, is it not dangerous for the health after it starts heating , the vapours I mean? Is there another way?
Thank you and Happy New Year!
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gjh42
Junior Member
Posts: 61
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Post by gjh42 on Jan 1, 2015 14:29:36 GMT -8
I think what you want for the feed tube is a steel liner that is surrounded by secondary air supply inlet, so the incoming air is preheated at the same time as it cools the feed. There have been examples of this posted before, whether here or at permies.com I don't remember.
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nemo
New Member
Posts: 48
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Post by nemo on Jan 1, 2015 16:01:29 GMT -8
Funny that you mentioned that secondary inlet and I looked it up to see what it means and this is something I improvised the moment I have built the feed. I thought it's easier to clean and safer since you can cover the top of the j tube feed and still get air. I did not know if this was something to do on a rmh and I took the risk. Now I see i did ok but still does not solve the heating of the feed. Still looking.
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Post by matthewwalker on Jan 1, 2015 19:58:52 GMT -8
What you are discovering is the reason I don't care for fire brick feeds, personally. They do work, and are durable, but eventually they heat up to where the fuel instantly pyrolizes completely and create smokeback. The coal build up is also a function of the heavy firebricks robbing heat from the coals. I personally am a fan of using insulated materials for the feed, but that has other problems, namely durability. So, there are compromises and trade offs, and I don't think there is one clear winner. It all depends on your design goal, your fuel, your burning habits, and what materials you have available to you, among other things. My preferred build is insulated castable refractory for the feed, it rides the line between dense firebrick and my softer insulated DIY mix. I've found that it's plenty durable to wood abuse, and doesn't heat up to where it harms performance. I also really like Peter's metal design as built by Sandy at Dragon Heaters, but I haven't had much experience with it other than one build I didn't get to spend much time with.
For barrel paint look for automotive exhaust paint, sometimes called "header" paint. There's one version rated to 2000F, and it will smoke as it cures but once it's set it holds up fine on the barrel. Comes in Mopar orange too!
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Post by satamax on Jan 1, 2015 22:04:35 GMT -8
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Post by matthewwalker on Jan 1, 2015 22:11:13 GMT -8
They don't like these in Romania?
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