as stated its not going to cool as fast as steel but it should do fine with a little taller heat riser. The barrel is cheap and plentiful and it works well so we use it. developing new barrel type things is an interest of ours because we know that what urns some folks off is the barrel.
I would warn that you will want to make the stove with clean outs that allow you to clean the manifold all the way around with out removing the barrel/masonry and you will want to be able to remove the capstone to get to the top of the heat riser.
the cleaning schedule should be once a year so setting the barrel in cob so you cant get to these parts is not recommended.
Just getting started so thank you
At ranch II we have no solid fuel so the RMH is very attracitve. Jon's idea, the clay liner, is a good adaptation for his use.
I've watched several videos and can track changes and perfections. Clean outs and material used in the firebox in particular.
I think you will find that by years end I will have a few more refinements. Again thanks for the confidence it keeps me going.
Jon Adams wrote:Thanks for the avdvice. The liner is fairly inexpensive at $35 each and I would only need two to get 48 inches in height.
I had been looking for those. the biggest I can get locally is 16x12s. I am not willing to order outside local so I gave up. I have covered my "barrel" with bricks with no problems at all. I would say that the whole action of what happens at the top of the riser is poorly understood and the heat flow away from that area by radiation vs. conduction through brick has not been well tested. Check out this link:
For a set of RMH builds that all use masonry in place of a barrel. I have seen other masonry topped RMHs on the internet too. This is virgin territory still open for experimentation. Build it outside first to test. $70 does not seem over much to try out. If I could source them here I would try that as i think those liners look nicer than a drum and easier to erect than brick. How many come to a pallet? I can probably get them here if I order a whole pallet.
the lid will be steel with a copper tube/water heat sink on top of it to heat some water for the chickens and for extra thermal mass.
Not so sure I would do that. My reason being that the water coil ends up being horizontal. Any part of that loop that ends up high will collect steam. Any of the water "coils" (normally S shaped actually) i have seen are vertical ones where there is a clear upwards path from intake to exit with no possible high pockets in the path. I would suggest such an S shaped tube inside the "barrel". You are doing a nice square one and could offset it to one side to make room for your S. Copper may not be good enough though. A good understanding of high pressure plumbing is a must, even if you intend to leave your reservoir open to the air.
I am also wondering if I could use a round 8" chimney(6" inside) liner for the heat riser, and if so would I still need to insulate around it as it is built to stop heat transfer. I am new to this but have always been a think outside the box kind of guy so these are just a few ideas I am floating out to the masses. I am also looking for the best detailed information I can find so if you could point me in the right direction I would be very greatful.
Yes you could use round flue. Because it is only one inch thick, I would insulate it. I would put a layer of roxul around it (welding blanket would work too) and some metal hardware cloth or sheet steel around it.
I am thinking that if you are putting the burn tunnel through the side you may have to do this... or cut up from the bottom. Anyway I thought the pictures might give you some ideas.