First post to Permies, got to say I have learned so much since happening upon the RMH on the internet. I picked up fire brick for 50 cents each, and drove my prius and trailer 100 miles to get it. Way over loaded, but it is used to it, at 220,000 miles, I've been testing loads since it had 50,000 miles. Anyway I now have a good selection of brick. Still reading Ianto's book, and looking over ernie and erica's as builts. Plenty of reading to do, but got my first test up today and fired it. It did well for a first try and dry stacked brick. I have clayish soil in my field, but still trying to process some samples. It dries white, I suspect it has too much dirt in it. Anyway, I don't have much to ask at this point, but figure I could post some pics, and begin my story.
Hey, beautiful location by the way. Nice lugging-prius. And that looks like quite a burly stove-core. I mean it looks HUGE. Maybe it looks larger, in the picture, than it is, in actuality-- but I wanted to share this with you, just in case: this was a recent post from a different thread:
Larger diameters can work too, but there is a limit: if ducting is too large, then the system will have the potential of getting REALLY HOT. This means that the design will require different materials (with higher-heat-resistance) than the standard rocket-mass-heater stuff. There is a podcast by Paul Wheaton, Ernie and Erica Wisner, which talks about exactly this. The podcast is long, and they talk about a lot of stuff, but eventually they mention the maximum size rocket mass heater duct. You can get the podcast here: http://www.richsoil.com/permaculture/182-rocket-ma...ters-permaculture-podcast-019/
Looks really awesome though. A pile of fire bricks is a great way to get started!
Oh and another thing: I recently was testing my stove-core, which is made of bricks. I did a full mock-up, with a barrel and pipes and all. I applied some mud as temporary mortar to seal some of the main cracks and holes, but the darn thing just wouldn't draft correctly. It was getting 100% smoke-back. Not drawing any air in the proper direction. The next day I rebuilt the whole thing, again using that mud as temporary mortar, but this time I mortared between nearly every brick-- especially throughout the heat-riser. It produced a lot of steam (during the first hour or two), but otherwise it drew and drafted a lot better. So.. moral of the story is, when building semi-full-scale mock-up, don't underestimate the importance of mortaring all the cracks in the bricks.
I Am guilty, I had just unloaded my 3500 Lbs of fire brick, and had about an hour to kill before work, so I slapped it together, without measuring. I promise the next test will be close to 28 to 30 cu" dimensions. I finally found a vein of clay in a cut out along hwy 95 on my way to Lewiston. Here's a sample of the clay ore I got yesterday.