Repurposed 100lb pig rocket heater (minus the mass)

Hello everyone, new to the community and here to share.

First off, I would like to introduce myself. My name is David I am a 28yo welder and metal fabricator living in Northwestern Minnesota (it can get -30F to -40F quite easily here). I spend most of my time fooling around with stuff and building solutions to problems. Recently we had a storm that took down a few large trees on my property and after cleaning it all up I was left with a massive wood pile that I didn't know what to do with. I also had another problem, propane gets expensive and trying to keep the shop from freezing can take a few tanks. One day of one youtube excursions I stumbled acrossed Rocket Mass Heaters (and a lot of your videos ). After quite a lot of digging around, I decided to build one. I found and old propane tank in the farms scrap pile, a 5"x1/8" ERW riser and 5"x7"x1/4" burn tunnel and got to work. Even though the riser isn't insulated and it has a 2" headspace, I am very happy with the results. I fired it up today with 8 1.5"x1.5" pine wood stakes, I had it up to 100F in the shop before I couldnt take it anymore and opened the doors (it is 40F outside with snow on the way)

Unfortunately, during this time my big welder broke and I had to use my little welder. This took a very, very long time and didn't look as nice as I wanted it to, but since the was just a test to see how well it would work I didn't really care about how it looked. Also, in the future I plan on removing ALL of the paint before starting it, man that stank when it got warm.

















http://www.youtube.com/watch?v=pEsvufYulyU

I discovered today that my shop camera can pick up infrared heat, there is NO visible light coming from this barrel AT ALL. The pinkish hue from the top of the barrel and the firebox are actually invisible infrared light.

David : Many Types of Cameras are capable of this function, and it is possible to even create 'night vision goggles ', I believe a good place to look for more information on this
would be at - ' Instructables.com ' - I just learned that many of these can show which circuits in a circuit panel box have been being used/ worked hard by an I.F. glow !

For the craft ,think like fire, flow like gas, Dont be the Marshmallow,Your comments are solicited and Welcome PYRO - Magically Big AL !

Late note : David, did you have any special reason why you went mass-less ?

Viz : The paint burning off, yah really Nasty, there is as good series of Videos at our sister site richsoil.com Click on the (Rocket Mass Heater) 'more info' icon and watch the
series, there is a real good way shown to deal with the paint issue and lock the zinc onto the stove pipe so that that is not an issue, though a Spanish R.M.H. builder puts an extra
final overwrap of household aluminum foil- shiny side in- and says his way is even better ! Out side of that, I don't watch much R.M.H. stuff on U-Tube Land, there is a lot of crap
out there ! A. L.

There was really no 'reason' I went massless. The main reason I built it this way was to dump at much heat as possible into the shop efficiently and quickly (which it does very, very well). There is a vertical dead space behind the RH that I have been thinking about using as mass, but I am not 100% on that yet. The biggest thing I can think of is just simply the lack of space that I am willing to sacrifice, it is pretty valuable in a 18x24 shop.

David.

How do you clean it out? Or is that the next modification?

Honestly its pretty simple, I bust up the ash in the firebox and suck it out with a vacuum, then I flip it around and get the ash out from the back side, the amount of ash in the back is minimal and only accumulates if I aggressively burn small and light feedstocks like paper.  I still use this heater 9 years later, its extremely effective and efficient.

The only thing I would do different if I make a new one, install a traditional firebox under the propane tank, set it up so I can swap back and forth and add angle iron to the tank's surface, alternatively you could add water coils to the surface and use it as a boiler with a heat exchanger. Adding angle iron will allow it to passively transfer extraordinary amounts of heat to the air, I'd even take a step further and wrap an aluminum jacket around the fins to add even more transfer area and use forced air to move the heat. Rocket stoves are the best kept secret in passive off grid heating. Adding a firebox to it would make it way more versatile, the way it is setup now with the 5x7 opening I am limited to pellets and small wood scraps (2x4s and smaller, though it has worked well for the better part of a decade I would just like to be able to feed it larger scraps and cardboard boxes from the property instead of wasting them in the bonfire.

Hey David, gotta like your very cool (and very hot!) heater.

And it's extra cool to hear your in-the-field report 9 years later. Thanks!

P.S., now I want one.

Great to hear that your first experiment is still working well.
Rather than add a traditional firebox if you want to increase capacity, you could make a larger rocket combustion chamber. I have found that my 8" J-tube RMH draws fine with a 6" stovepipe chimney (it has good natural draft which probably makes a difference.)
A 7x7 square tube feed and burn tunnel with an 8" pipe riser would give a beast of a heater that could easily supply a brick "column" shaped bell behind the stove before you exit to the chimney, holding a good amount of heat to even out the temperature in the shop. This size is also easy to clean ash out of with a tuna can sized scoop on a short handle, no need to get out the vacuum.

do you have any pictures of the inside?  What did you use for a heat riser?

David said in his first post "a 5"x1/8" ERW riser" which I take to mean a 5" diameter pipe.