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So, i got a 55 gallon barrel and put a rocket stove together but I think I am having some issues or did something wrong. Anyway, I took 4"pipe and surrounded it by a 6" pipe and filed the space with vermiculite. I tested the flue before installing and worked life a charm. I cut the holes in the drum and resealed it with the original lid (this, making it easy to move until I decide where to put it). I have rough install of flue and exhaust. Exhaust is also 4"and I just put a 90 degree connection there. The 6" flue outer shell is maybe 1 to 1.5 inches shorter than the stack. The stack is roughly 2 inches from the top of the barrel.
Anyway, I get a good burn and good exhaust flow but I think I have 2 issues. 1) outside the top (50 to60 degree weather) gets hot enough to barely boil water in about 15 to 20 minutes. Take the lid off of the pot and it won't boil at all. 2) the exhaust fumes will either snuff out any flame that comes near it or the gasses in the exhaust will ignite to create a longer flame for a short time. So, i know the wood is being gassified but it doesn't seem to be burning completely in the barrel.
A few notes. I can get the flame and embers inside the 4" intake hot enough to get a drop forged wrench bright red with very little wood.

So, with that said, dies this all seem normal? When I extend the exhaust will it make a difference? I will be adding a burn chute which will be a 4" round have receiver so that the wood will stand straight up. I will surround that with a 6" receiver and insulate again.

So far I'm pretty happy with the outcome but some advice on this would be greatly appreciated
 
pollinator
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Jon Lim : A belated welcome to Permies.com, our sister site richsoil.com, and our Rocket and wood stove Forum threads !

This is your 3rd post here, I did take the time to re-read through them! Taken individually They each read like a fellow member that has been
following these pages awhile, and asking well thought out questions. As a whole, they show a real hunger to grasp the concepts of our Rocket
Mass Heater RMH, and an agreeable eagerness to start your build ! We all started where you did, it is often very hard to know exactly when
you have a certain grasp of the fundamentals of Rocket Building and we generally try to gage the background and skill sets of our newer
Fellow Members!

In these pages we normally encourage enquiries about starting a Rocket Build by sharing as many facts as related to the questions we get!

Specifically, before this point you SHOULD have been told that all 1st time builds should be 6'', or 8'' RMH systems! Due to high flow losses, in
both volume and speed, and the friction loses of laminar flow, it is so very hard to down size a rockets internal plumbing to a 4'' rocket system,
-that many of your fellow members with successful rocket mass heater Builds in the 6 and 8'' range have failed in the attempt to make a smaller
diameter RMH !

Obviously we failed to tell you in a timely enough manner ! Can I as one of your fellow member say Sorry( ! !!! ), and then lets move on ?

At this rather late date my best advice to you is to put your 4'' system on hold ! Just for Now ! Also I want to strangely suggest that you goto ->

Rocketstoves.com, to download a PDF Copy of The brand new 3rd edition of Ianto Evens' masterpiece Rocket Mass Heaters, this is
" The Book" ! With over 100,000 rocket mass heaters RMHs Built World Wide, most were made following 'The Book' and 95 percent of all the 1st
time builds (that worked) were made from this book ! You can consider it a small investment in saving you Time, Money, And Frustration as you
Re-start your build !

After studying The Book, you can then Expect to come here to Question or make comments on what you read- Knowing that you are using the
same words to describe the Size(s) Shapes and Orientations of all of the RMHs parts to themselves and each other !

With the spirit and drive you have already shown, moving forward to the day when you first hear the Roar of Your Own rocket mass heater will
soon follow. accept our help in a more timely manner and that day will get here all the sooner ! please let us hear from you ! Big AL
 
Jon Lim
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Thanks for your reply. The reason I got into rockets stoves was the relative easiness of using scrap so in used what I had available to me. I'm not one to give up easily so I will put all effort forward to making a 4" work.
Would it be beneficial to use a smaller diameter exhaust to build up a bit of pressure in the barrel? It would slow down my burn but build up heat (think like an h box on an old motorcycle). Or would it just be beneficial to increase the length of the exhaust pipe to make it difficult for an easy exit of gasses.
Now. I drilled into the side of the barrel to make it movable in case of an emergency. The 4" is also a bonus because i can hide the light from the flame pretty easily.
What I haven't done yet is seal any gaps where air can be sacked it by the holes I drilled in the barrel. Could this also be my issue? I was trying a dry run before I completed the whole thing
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Jon lim : 1)No! 2)building up pressure is the last thing you want to do.3)a nice long vertical chimney will add draw, not subtract it, The horizontal run must be short
to overcome the high friction loses of the smaller diameter pipe ! 4) Your barrel must be sealed air tight to work 5) I am not sure if you are telling me you tried to
run your prototype 4'' system already with unsealed holes in the barrel but the only unsealed hole in the barrel can only be for your chimney, As soon as you place
a barrel over the Heat Riser you must immediately add a 10-12' tall vertical chimney, even if it is only for testing the rocket burner alone without any Thermal mass,
see #3 above ! Again, this is all in ''The Book" but we will be here to support you ! Big AL
 
Jon Lim
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Hey big al. I have the book, read it about a half dozen times and wrote my thesis citing it several times. My thoughts are purely theoretical and asking on others on their experiments and experiences.
Thinking purely theoretical, the gas still being in the exhaust means that not everything is being burned off. What could theoretically be causing the gas not to be burned off inside the barrel? Sealed up, same issue which leads me to believe the shirt exit flue is working against me allows get the air to be cooled too quickly.
Is my theory incorrect?
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Jon Lim :Not sure what you mean, general temps for creation of wood gases 500 degrees F, ignition at 600 dF, a lit cigarette Burns at 1000dF,
with a well sealed barrel and a tall exit chimney within 5 minutes you should be able to drop drops of water onto the top of the drum and see
the water bead up and dance !

Again, I would try again to seal up the barrel with wet mud, the total height of your Heat Riser must be a minimum of 3Xs the depth of the
feed tube, if it will not draw with the barrel off, then your dry stacking is not tight enough!

please excuse the typing -one-handed with orphan 3 week kitten on shoulder ! again, we are here for you ! Big AL
 
Jon Lim
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Hey big al,
Thanks, i am getting plenty of draw and I can even boil water on the barrel. I can not, however, get it so hot I can boil water quickly in a pot. That's my concern. Great draw, great everything, somewhat adequate heat. I will try and upload a video at some point.
 
allen lumley
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Location: Northern New York Zone4-5 the OUTER 'RONDACs percip 36''
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Jon Lim : Just a guess, But if you have indeed pulled a rabbit out of your hat, you still are only getting 40% of your heat being radiated off of the Barrel Top AND
the Barrel sides! The other 60% of the Heat energy produced by your rocket will enter the horizontal run of stovepipe and ether be absorbed by the Thermal Mass
or be lost up the last vertical chimney !

You are pretty much on uncharged waters here and may have better luck with Bells, as I have already told you, this is a hard build to get right ! For the Craft! Big AL
 
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