A Rutha

I've torn down the old version now, which only really worked as an L-rocket. I think it was simply the wrong diameter (too large probably).

I've re-built now in smaller. In the picture you can still see part of the wall (this has now been torn down actually).

My system now looks like this and the interior is entirely built from cheap HD pavers. As you can see, yes I'm really in Canada, my chimney is just loosely stacked Tim Horton's Coffee cans with the bottom removed. This system now draws nicely. Actually it begins to draw really quickly. A bit of paper/carton and it's started, vs. the old version which would suck air the wrong way around even when it was hot.


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Today I've remixed all the taken down cob and insulated the thing all around. I still have the steel plate on top but I gotta use the dry nights/days to get the cob dried. But now at least it's cobbed in place instead of just held down with left over bricks. I only laid it on a ring of cob this time and cobbed it in on two sides only and there's not a lot of smoke coming out on top at all.

Thanks guys. Ceramic sounds awesome but a bit big right now (and not easy to find I would presume). I like the idea of the rope seal. I guess I could use that.

I had thought of getting a cheap cast iron pan at first and just putting that in (upside down) but was worried about the weather. Would cast iron be ok if it's covered or wouldn't it start to rust even from just dew and such? I don't have a proper cover yet and was using the dry spell to get this done and now with rain in the forecast I just have it covered with a tarp that's weighed down.

So it's almost dry and I've fired it up for cooking today. The steel top plate however is bending quite a bit. I thought I could just put it on top and cob around it to keep it in place. Unfortunately it bends up around the edges. This is bad in two ways because it meant I needed to repair some cracks from the edges lifting but also my cast iron pan did not make full contact and never got really hot enough. Bacon took forever. Good for really nice slow cooked scrambled eggs though.

Any tips for integrating a hot plate for cooking? Please no 55 gal drum suggestions :)

That said the whole thing is just really nice and warm at the moment. It's been 3 hours since I fired it last and it's just radiating heat all around now. Awesome.

I've built a 'one bell' version now, left the L-shape feed for now and closed it up all around. Made the cob from just sand and non-clumping clay kitty litter. It draws and the smoke/hot gases come out the other end. My chimney is a bit short at the moment, since I'm just reusing the cut up pipe but at least for testing I can probably rig up some coffee 'tin' cans. Making a better 'hot plate' now for cooking (since I'm not using a drum).

After it fully dries I'll probably see all the clay/sand mixing mistakes I made and redo half of it :)

Gerry Parent wrote:A couple of things I'm noticing in your dry stack of bricks.

Can you put them on their side instead of flat as you have them?
Also, is the burn tunnel only one brick deep? Your dimensions look really small and constricting in the photo.
If you make a 6" J tube, the dimensions can be about 5.5" x 5.5" all the way through.  
Yours look like their stacked at 1.5" x 3" or so.

For the "2 bells" version I did stack them on their sides. This version is the 'basic' one, like for example this (you just gotta love the kid lol - but there's a bazillion of these out there) https://www.youtube.com/watch?v=v26b3jrylEc

The tunnel is 2 bricks high, which is the same size as the riser and also the J feed. The brick that those sticks are resting on in the front are the first row of bricks. The one on the left of that is turned and in the J version would be turned back such that it's where the sticks rest now and creates the second row. As you can see there's 2 rows of bricks on top of the tunnel and the whole front is 4 bricks high. So then a brick across that second row in the front to close the third row of bricks, which is the first row you see creating the top of the tunnel and then a fourth row on top of that.

Attaching a pic I just took. This is in "L mode" as you can see. For J mode I turn the bricks you see sticking out and place the other ones around on top. That large-ish piece of wood actually roared nicely in the L mode version but even the smaller ones didn't work at all in J mode.

Also I think after googling more it should be perfectly fine to buy cheapo clay kitty litter without additives and use that and my sandbox sand for trying this out. The first posts you find are always the ones that say you can't and that also tell you can't use hay only straw etc. But after a while it's possible to find that anything goes really. Especially for trial and error and taking it down again and back up differently etc. Finding clay seems impossible here. Pure clay kitty litter is easy. Finding straw is hard, hay I have plenty and cheap for the Guinea pigs from the horse farm around the corner.

If it really needs no air leaks at all then that would definitely be it, as those bricks will leave some tiny gaps here and there. I thought I could get this going, try out how I like it, even if not at max efficiency etc. I guess there's no such thing as free lunch and I gotta go all in :)

Thanks for the help!

So, tried both the regular "J tube style brick rocket stove" you see all over Youtube as well as the space saving version I showed. Tried that one first actually and just couldn't get it to draft at all. I then tried the regular style J made of bricks and I had to 'help it along' by burning something in the riser but really it never worked very well at all. As soon as I opened the J to make it an L, it starting roaring just like my HVAC duct version did. Let that burn for quite a while and then started 'closing it up' again to make it a J style. That just totally killed the nice little fire that was roaring before.

Thanks. I hope I'll find some of those somewhere around here, if my trials work out with the cheap brick.

Also what all this made me think of was what my grandma used to have in her house back in Germany. It sat in the wall between the kitchen (in the eating nook) and the living room. Here a nice short English language source with nice pictures of a few: https://www.rvharvey.com/kachelofen.htm

I tried it with the bricks I have but I think I had way too many gaps (they're not rectangular bricks, which was fine to hold the sand "insulation" around the metal tube but doesn't work as the actual material. So I'll have to get a bunch of new bricks to try this out.

That said I think I found what I was looking for as a base for the space efficiency now  

Minus the real mass to the side but good enough for trying something and adjusting I'd say.