RMH for Dummies! Please help guide me through my first build!

Stacy, i always heard that horse manure is better, since horses don't digest cellulose. The fibers are finely cut, but still present. While cow manure is just rotten vegetables, more or less.

Satamax Antone wrote:Stacy, i always heard that horse manure is better, since horses don't digest cellulose. The fibers are finely cut, but still present. While cow manure is just rotten vegetables, more or less.

Awesome!  I would much rather use horse manure, any day.
Thanks!

Hi All-
  Just wanted to say how THANKFUL I am for all of you wonderful Permies out there!!! :)
 You have been instrumental with your help, input, feedback, support and humor.  This thanksgiving, we will be eating dinner with a baby dragon roaring in the next room.
There have been days where I wanted to throw in the towel with my build. There are also times that my build and my "Permies friends" made the daily grind of life that much brighter.
I thank you all!
Happy Thanksgiving!!!

Staci

Beyond hope.
I started putting on the last cob layer today (straw cob), poking in to get a join and then smoothing out the surface.
Cracks are forming EVERYWHERE.  I keep wetting to slow the drying, and filling in cracks and smoothing.
Problem is, I have yet to achieve crack free cob.
If I reduce the amount of clay (recommended course for cracking cob), it turns to sandy crumble and sloughs away, especially when adding straw.  It is just sandy straw that will stick to nothing.
I have experimented with various amounts of dirt as well.  Also some potter clay scraps vs. fire clay.
I did read recently, that someone else had the same experience when using the fire clay and sand.
I have been unable to find any local source of clay, try as I might, except near the salmon stream where salmon are still actively spawning.
I feel like I am back to my (unhappy) starting point. like trying to read, but having never mastered the alphabet.
If it is all cracking, do I just plaster over cracks?

Hi Stacie;  
Chin up keep cobbing.

 In reality cracks don't hurt anything other than looks, unless they are into your manifold.

The cob over my barrel developed's  cracks every season,  I just keep rubbing more sandy cob in .

Stacie, you should take this with a HUGE grain of salt.  My input here is certainly not expert advice.  You've done way more cob work than I have in your build.  For my pebble style I've used cob mostly just for around my manifold and to set the barrel.  That said, I too kept having the cob crack around the barrel.  I have little doubt the root cause there was the expansion of the barrel.  Still I kept trying to fill, plaster over, smooth out the cracks and they kept coming back the next burn.  Then I added another layer of an inch or so in a ring all around the barrel.  I'm hand mixing fairly small batches of cob.  To do this layer I actually ended up making two different batches to get all the way around.  One batch was made as I had been doing most of my mixes, fairly dry, thinking that with less moisture in it to begin with there would be less shrinking and less to evaporate.  The other batch I ended up adding a bit too much water, or so I thought.  It wasn't exactly soupy, but it was definitely wetter and stickier all around.  Initially I couldn't really smooth it out well with my hands because it was just too sticky.  Anyway, after the next burn I again got cracks.  However, I observed that they only happened in the cob that I had mixed to be drier.  The wet, sticky mix was perfect and crack free.  (I should note that I was using the exact same ratio of fireclay and sand in each mix.  The amount of water was the only difference.)

This morning I decided to try making up a wet sticky mix to fill in the new large cracks in what was the dry mix.  I first painted the areas with generous amounts of water to moisten it a bit at least.  Then I worked in the wet mix smoothing it as best as I could.  Once it dries a bit I found that was the time to go back and smooth it more.  Anyway, I've been burning the RMH all day today since I also added the remainder of my pea gravel and rock mass and I wanted to get that mass up to temp.  The cob section has certainly fully dried by now and the crack repairs worked for me at last!  (well there is one tiny hair line crack if you look hard)

So based on this recent observation, and without the benefit of further study (hence why you should take this with a grain of salt) I'd suggest that perhaps you aren't getting the mix wet enough to allow the clay in it to be it's full sticky self making good bonds to all the other materials.

David Huang wrote:


So based on this recent observation, and without the benefit of further study (hence why you should take this with a grain of salt) I'd suggest that perhaps you aren't getting the mix wet enough to allow the clay in it to be it's full sticky self making good bonds to all the other materials.

Hi David,
 Thank you for the thoughtful reply!
Funny thing:  I had two batches of cob made up.  One I pulled into the house, other was rolled in a tarp outside.
Well, I guess it was leaky, cause when I pulled that one in today, it is very sloppy. (from the rain). SO, by the shear will of nature, I am trying your suggestion!
We'll see how it goes this round.

Are you doing straight fire clay and sand?

Thanks again!
Staci

I have zero experience with RMHs, but for 20+ years I’ve worked with clay, so maybe I can give you at least some ideas about things to try.

One thing we used to do for sculptural pieces was to make a paper-infused clay. It doesn’t shrink as much and it also joins very well to dry clay (a difficult thing to accomplish, especially without cracking). You soak shredded paper (nothing slick, coated or shiny) overnight in a bucket of warm water. Toilet paper (sans cardboard roll of course) is easiest since it’s so soft and it doesn’t need shredding. The mix is a matter of experimentation. I’d probably start off with 2-3 rolls in a 5 gallon bucket if it were me, but maybe it’s best to start out with a smaller bucket at first and see how it works for you. Next morning, use a drill-mounted paint or masonry mixer to mush it all up. It doesn’t need to be perfectly homogenous, but try to eliminate any lumps. Use this paper-infused water to make your clay. I’d probably start out with EPK (Edgar Plastic Kaolin) (dry clay) because it’s easy to find. Any kaolin should work, the less plastic the better, but EPK isn’t that plastic—just more so than some other kaolin types. You’ll have to buy it most likely, but it’s not that bad. Any potters’ supply house should have it. It’s white. If that bothers you, you can also get some red iron oxide (aka powdered rust) to color it... it doesn’t take much. Or you can cover it with a thin slip of red clay later on. Mix your powdered clay into some of your paper/water until you get the consistency you want. If you’re doing sculptural decorating, you’ll want it dryer than if you’re just putting on a smooth layer. If you use a flexible “rib” to compress the surface as you work, it will be less likely to crack. Buy one at a hobby store, or cut a kidney-shape from a plastic lid, 3-4” or whatever size ends up working for you. Use it at an acute angle to smooth and compress the surface.

Once the clay has dried (and if it doesn’t crack), You can “fire” it by heating up your wee dragon. If you can get it up close to the boiling point in your altitude and hold it there without going clear to boiling for half an hour, that would be ideal, but as long as it’s dry and not terribly thick (say no more than a half inch), you’ll be giving it its best chance of working if it’s going to. WARNING:The paper will burn out if it gets hot enough—not with flames, but it does smell bad until it all burns out. The straw no doubt does the same once it’s dry, and if it gets hot enough to burn. If you do get cracks, mix up some buttermilk-thickness paperclay slurry and paint it on where you’re having troubles. Feather the edges. When it gets dry enough not to stick too much, you can burnish it in with some thick plastic wrap or a plastic shopping bag over your fingers. A little oil on the surface sometimes helps. Cooking spray is easy to use, but any non-toxic oil or fat will work.

Assuming all this works and you get your bass-relief art to hold up and not crack too much but you’re still not quite satisfied with the smoothness of your surface, you can mix up a thinner slip from a more plastic clay. Buying some sieved clay will give you a prettier result than the fire clay. Red earthenware or white ball clay would be my choice. You can dig it yourself, however this involves more preparation. Sieving, mostly. If your surface is rough, you can sand it. Steel wool works, but it IS a lot of work for such a large piece. You can also just paint on the slip and burnish it in with the rib as you work. Honestly, don’t work too hard. As the slip and/or oil dries, that nice sheen will fade. You can wax with a floor wax if you really want it, but only in places where it won’t get hot enough to burn it out.

I think that where the clay interfaces with the drum, it will always crack. The thermal expansion and contractions of the steel and the clay will not match, thus  creating tension. Because dry clay is more brittle than most steel, it will crack but the steel will not. The paper clay may help, but I’d be very surprised at no cracking.

These are just ideas, and maybe you’re not into that much fussing around (and maybe they won’t work anyway) but that’s what I’d start with if I were looking to finish a baby dragon and make her lovely.

As long as you have enough straw chopped up into shorter pieces in there, and spend plenty of time mixing the wet cob by smearing it around a LOT with the straw first so that the clay really grabs on to the straw, then mix all that on to the wet existing layer that will need a rough surface to grab, you should be in good shape. You can then finish with a thin layer like 1/4" that doesn't have any straw in it. I'm out of town right now so I can't check it, but the book The Hand Sculpted House has plenty of detail in cob construction pointers that could help.

As far as using disolved paper mixed in, I'm not sure if the paper fibers would be long enough using toilet paper, but who knows. It definitely wouldn't reach nearly 200F degrees as mentioned anywhere on the mass, including near the burn tunnel if properly insulated. The mass might hit 150 if a really hot burn was kept going for hours.

You could perhaps get fire stove gasket to embed around the barrel where it meets the cob to create a thermal transition to prevent the cob from cracking.

Continuing to add little bits of cob to the cracks might work, but if you find the same spot keeps cracking despite that, it would likely be an expansion point and you either dig it out a bit and add back cob with plenty of straw in case it was lacking it, or just accept the little cracks so long as they aren't leading into the exhaust path like the moanifold or stratification chambers if any.

Mark Tudor wrote:The Hand Sculpted House has plenty of detail in cob construction pointers that could help.

You could perhaps get fire stove gasket to embed around the barrel where it meets the cob to create a thermal transition to prevent the cob from cracking.

Thanks, Mark!
I like the gasket idea.
I will see if I can find the book at the library.

Cindy Skillman wrote:I have zero experience with RMHs, but for 20+ years I’ve worked with clay, so maybe I can give you at least some ideas about things to try.

These are just ideas, and maybe you’re not into that much fussing around (and maybe they won’t work anyway) but that’s what I’d start with if I were looking to finish a baby dragon and make her lovely.

Thank you, Cindy!
It is mostly clay work at this point.  I appreciate the input. I got the manifold and 1/4 the first bench covered today. I'll see how she weathers and then may experiment with the T.P.
Your explanation of the barrel/clay junction sounds spot on. I like Mike Tudor's idea of the stove gasket there- kind of a buffer/transition zone between the steel and clay.

Thanks again for your thoughts!

Are you doing straight fire clay and sand?

Yes, I decided to go that route on this project since I wasn't going to need all that much cob and it would let me keep a consistent mix.  Oh, and it would let me mix the two together while they were still dry ingredients making an even mix much easier.  I ended up using a ratio of 2 parts dry fireclay by volume to 3 parts sand by volume.  For sand I got the bags of it you can find at home improvement stores by the redi-mix cement.  I should note that economically speaking this is the worst way to go.  I certainly wouldn't have done it this way if I was doing major cob work like you are.

Thanks, Staci. :)

I’m so much on the kiln track that I said some things that are confusing and a little silly for an RMH. It’s hard to break old ways of thinking. When I said to bring it to near boiling temp... I guess that’s not a problem with the the RMH as it apparently doesn’t reach those temperatures anyway. In a kiln firing you need to do that to get all the ambient moisture out before you pass through the temps where ambient moisture (room humidity in the otherwise dry clay) would suddenly flash into steam and blow off bits of your pot (or just blow the whole thing up). As you’re not going that high, you shouldn’t worry about that. Sorry for the confusing remarks on that front.

That said, I’m beyond impressed with what you’ve accomplished. It’s nothing short of a life-changing achievement. You are now that rare thing—a person who has successfully built a rocket mass heater! If you’re ever feeling low, you can always say to yourself, “Yeah, but I formed my own dragon! Who else does that? Hardly anyone, that’s who!”

My husband and I agreed that I would build one in my studio next spring/summer. I know he just said it to get me to stop talking about building one in the house. :lol: And because he doesn’t believe I’ll really do it. Silly boy. I don’t do much pottery any more. After 25 years I just kind of got tired of it. I paint now. It’s much less labor-intensive. I think I’d enjoy my studio a great deal more with something (besides me) alive in there. A dragon sounds like the perfect companion. (And I do have lots and lots of clay!)

Slowly, but surely.  
Some progress...

So, any news?

Yes Stacie:  We would like an update please.   How is the cob coming ?  How is the dragon roaring ?  Any smoke back issues still?  Did you buy a load of dry wood ?  Photo's please.

Thank you, Thomas and Satamax, for checking!

It is almost finished and ready for its long dry time (before plaster).  I need one more batch of cob to finish the end of the bench and the back of the manifold (chimney pipe), and up the barrel aways.
There is cracking, but it appears superficial.
I did purchase half a cord of wood, "dried, seasoned" supposedly, but not super great.  Learning as I go.
Yesterday I picked up a pile of free branches, cut last spring.
I am getting really adept at ax wielding and wood splitting!

Question: what is best for sawing  (easiest!) for small logs/branches (1-3" diameter)??

My little dragon is working well!!  IF I use only round pieces, it runs like a dream.  Easy, no smoke- perfect.  
IF the rounds are too tall: smoke. (hence needing a way to trim the logs)
IF I use any splits ( square, rectangle, triangle): smoke and babysitting.

We have had unseasonably cold weather here: 20's-30's.  It is the ONLY heat source in that room.  It heats it up nicely, and also the surrounding areas in the rest of the house.
ANd the kettle of water is always ready for tea.
MOST awesome, I will run it for a few hours in the evening, shut it down around 8 pm, and in the morning the WHOLE ROOM is still warm!!! (we used to get frost on the inside windows).
 I can settle on the bench to drink my coffee and it is still warm!!

Hey Stacie;
 That's Awesome!  You and your RMH journey are an inspiration to more people than you can imagine.

Cutting small stuff,lets see)  hand saw if you like a workout, sawsall  tool corded or cordless , electric chain saw,  wood chop saw , skill saw,

I think as your mass cures you may be able to have taller wood.   I do it every day with my 8"

Watch craigs list under free stuff.  I have seen plenty of smaller piles of seasoned wood given away for the hauling. Not to mention places that have pallets.

Next summer maybe enlarge your wood shed, with new wood on one end and seasoned ready to burn at the other.

Are you using a tire bolted to your chopping block ?  Best way ever to hand split!

As it has gotten chillier here in Florida, I was wondering how your rmh was doing...glad to hear you are warm and that tea is brewing....I am headed out to reheat my tea, it cooled before I could drink it (not complaining, I have only covered tender plants one time so far : )

Praise God, you have done a great work for your family, your home, I hope you enjoy the winter, all cozy : )  thank you for sharing the trials and successes of your work.

I use this reciprocating saw which also turns into a jigsaw to cut small branches. https://www.amazon.com/dp/B01LW6OEMU/ref=cm_sw_r_cp_awdb_t1_e1RcCb1X3TPX8

I keep it in the car in case I see free pallets at local shops which I can cut up for wood.

Looking good Staci.

My tip for easy cutting of smaller wood, maybe 1 to 1.5 inches in diameter is a nice pair of loppers.  I got mine a few years ago for yard work and love them.  With my new RMH I'm thinking I may start hunting for some with even more leverage so I can cut larger diameters.  I would greatly enjoy being able to cut my "firewood" with what are essentially a big pair of scissors!

My new pebble style RMH has been doing fairly well, though I must admit it's not as efficient as I had hoped for.  I'm only using about half the wood I used to, which still isn't bad.  I was hoping for better though I knew I couldn't get it as efficient as it could be due to a lack of space for the heat exchange bench.  You mention that you can run yours for a few hours in the evening and still have the bench warm in the morning.  Can I ask, with your cob style in the few hours you burn does the bench heat up to where it physically feels warm to the touch, ie not just room temp?  Does it still feel warm like that in the morning?  Mine will heat to where the top surface is 80 to 90 degrees F after a several hour burn.  I feel like it should be doing better and wonder if cob is that much different?

Lots of air space with a pebble bench, solid mass of any kind will stay warm longer.
David;  Did you use pebbles, so it is easily (sort of) removed ?  Or is it a lack of clay?  Is your mass fully contained ?  I.E. completely surrounded with wood/brick/metal ?  If that is the case then simple dirt will hold more heat than pebbles.

Thomas, from what I can tell I did it as Paul did in his pebble style RMH.  I have the 4 DVD set DIY Rocket Mass Heaters.  I drilled what appeared to me to be even more vent holes in the bottom of my box to feed the cool air in and have large vent spaces along the top edge of box to allow the warm air out.  Filling the bench itself is a mix of 3/8" pea gravel with roughly hand sized rocks added in.  What I wasn't sure of from the videos was whether or not the bench was to be filled all the way to the top before the top was put on, or if an open air space was needed.  Currently my top is a mix of cement board that I could tile, and slabs of granite countertop off cuts.  I'm hoping to eventually get some rock slabs for the whole thing if I can find them for a reasonable price.  Right now I also have the box filled all the way to the top.  I'm thinking I need to do an experiment of leaving the top off, thus simulating an open air space and measuring to see if the rocks get hotter than when it is on.  The surrounding box is 2x4 wood construction with cement board sides that I will tile at a later date.

I realize a solid mass will be better but I was worried about the weight since it is on a mobile home floor like Paul's.  Though when I was wiggling underneath the trailer to brace the floor I was happy to see one of the long primary I-beams is centered to run underneath the entire length of my mass bench.  Hence, I'm thinking I might try cobbing up a section before the next heating season to see the difference.

David, I guess you are running flues through thermal mass and trying to create convective currents with these holes.

Graham, that would be my guess as to what the theory is for the pebble style.  Paul Wheaton had mentioned in one of the videos that when they tried it without the air vents the pebbles acted too insulative and didn't work too well.  Physical contact between the pebbles is too limited for conduction of heat to work that effectively I guess.

Question: what is best for sawing  (easiest!) for small logs/branches (1-3" diameter)??

Hi Staci,

I'm nearly finished splitting and stacking wood for next winter (Starting in June)
For small stuff (up to 3"), I don't think you can go past a cheap mitre saw for ease and safety.
I would personally prefer not to use a skill saw or a Reciprocating Saw.
If you want to use a bow saw then just remember there are 2 styles of blades.
A blade for green wood and one for dried wood. You will also need to clean the blade after use
if you are cutting green wood
Any suggestions for a cleaner to remove sap that is not toxic would be great from anyone please).

I'm very keen on reducing the amount of body strength and testosterone required to prepare firewood
as I would like to see systems that anyone from a 7-year-old to an 70-year-old (i hope) can do without too much stress or danger.
The great thing about RMH is that the wood from the waste stream (be it from construction timbers or the tree waste (too small to burn in a box heater) from cordwood operations)
is perfectly suited to burning in an RMH with minimal splitting work required.

Last year I took the side off my finger splitting fine kindling (with a machete). I had been procrastinating about getting a "kindling cracker" for a while. That incident made me do it.
The kindling cracker was invented by (at the time) a young girl (I believe she was 14 or 15 now 20) after her aunt lost a finger chopping kidling.
They are really good and all you need is a hammer. There are 2 sizes. I got the small one thinking I'd only use it for kindling but I spilt anything that will fit in it. The big one takes diameters up to 9 or 10".
You don't tend to have wood firing off either side as happens with a splitter or putting your back out whacking the wood with all your might. You can also split all the really twisted grain wood that is very hard to split with an axe. Here's a link https://www.kindlingcracker.com/

Hi-
 We lost power for 8 hours yesterday (due to high winds).
I was able to make dinner for my family, keep us warm and even made pop corn and hot cocoa.
Made it all worthwhile right there!

That looks like a major win!  Congratulations, well done!  Warm, well fed, happy family : )  

Dan Hatfield Ii wrote:Question: what is best for sawing  (easiest!) for small logs/branches (1-3" diameter)??

I'm very keen on reducing the amount of body strength and testosterone required to prepare firewood
as I would like to see systems that anyone from a 7-year-old to an 70-year-old (i hope) can do without too much stress or danger.
The great thing about RMH is that the wood from the waste stream (be it from construction timbers or the tree waste (too small to burn in a box heater) from cordwood operations)
is perfectly suited to burning in an RMH with minimal splitting work required.

Hi Dan,
  Thanks for the great feedback.  
I saw the kindling splitter and was debating it. Great to hear from someone who has actually used it.
Sorry about the finger shave- yikes!

beth Cromwell wrote:That looks like a major win!  Congratulations, well done!  Warm, well fed, happy family : )  

Thank you, Beth!

David Huang wrote:Looking good Staci.

My tip for easy cutting of smaller wood, maybe 1 to 1.5 inches in diameter is a nice pair of loppers.  I got mine a few years ago for yard work and love them.  With my new RMH I'm thinking I may start hunting for some with even more leverage so I can cut larger diameters.  I would greatly enjoy being able to cut my "firewood" with what are essentially a big pair of scissors!

My new pebble style RMH has been doing fairly well, though I must admit it's not as efficient as I had hoped for.  I'm only using about half the wood I used to, which still isn't bad.  I was hoping for better though I knew I couldn't get it as efficient as it could be due to a lack of space for the heat exchange bench.  You mention that you can run yours for a few hours in the evening and still have the bench warm in the morning.  Can I ask, with your cob style in the few hours you burn does the bench heat up to where it physically feels warm to the touch, ie not just room temp?  Does it still feel warm like that in the morning?  Mine will heat to where the top surface is 80 to 90 degrees F after a several hour burn.  I feel like it should be doing better and wonder if cob is that much different?

Hi David,
 I do have small loppers, but not so heavy duty.  I can justify adding some to my "arsenal" as I could prune the fruit trees and weedy maple trees in our yard as well.

Great news on your pebble RMH!   If I run mine for a few hours, the first portion of the bench gets very warm- you can sit on it still, but cozy.  The second half (after the 90 degree) pretty much warms to "room temperature"- not for "butt warming", per se, but not cold.  In the morning, the entire room will still be comfortable and warm.  By then the barrel is slightly warm to touch and bench is just "room temperature".
 Like Thomas mentioned, cob is a different animal than the pebble-type.  I had a solid brick floor  foundation to work with; it is great that you were able to adapt something to your space (definitely not solid brick!)
The great thing is that these  (RMH) seem to be dynamic systems to a degree- can modify, tweak, change.  Seems like you are already on the right path of experimenting.
I'll stayed tuned to your fine-tuning it!

thomas rubino wrote:Hey Stacie;
 
Are you using a tire bolted to your chopping block ?  Best way ever to hand split!

Thomas,
 I actually got it super-wedged into the tire! Stuck.
I was also using a wood grenade, which got wedged deep into the wood. Stuck.
Grenade stuck in wood, wood stuck in tire.
So I ended up with double stuck.  LOL. I had to abandon post and leave it for my husband to attend.
The tire I used was really unusually tall (almost like a race car tire, very wide). Maybe that was the issue...?
Been a bit gun shy after that.  For now, I chop on a stump, BUT I haven't had any very large pieces.  Nothing over 6".

Ha Stacie;
Don't feel bad. I get the wood stuck in my tire quite often.  
 Now that wood grenade...  sounds great (I've owned one) they only work good on a piece of wood that was going to split easy anyway.
If you need a wedge use the old style , they get stuck sometimes as well ,but you can usually knock them out sideways.
You might look at a Fiskars splitting axe.   I liked mine so much I bought a second!  

Super awesome you took care of your family while the power was down!  Next I'll have to tell you about alternative energy... Keep those lights burning while your neighbors sit with candles.

thomas rubino wrote:Ha Stacie;
 Next I'll have to tell you about alternative energy... Keep those lights burning while your neighbors sit with candles.

Hi Thomas,
 I will look into an old school wedge and the Fiskars ax.
I would love solar panels!! Our (wealthy) neighbors just got two enormous panels (each made of 20 or so smaller ones).
I see them (with green eyes) when I look out our front window.
 I hope to get there some day!!

An option for splitting wood is to attach a short piece of bungee cord to a chain, and have the bungee hook into the chain after wrapping around the log to split. It holds the log together as you chop but has some give and is to detach when you finish. Mention of 3 inch pieces though, why split those at all? Once you get a few smaller pieces going hot you can drop 1 or 2 pieces at 3 inch thickness in and you are set for a while right? I'm hoping so as my goal is to grow an acre or two of coppice to rotate through, cutting it at around 3 inches so I don't have to split it, just cut it at 15 inch lengths and it's done. But maybe that won't work, I haven't given it a try.

Mark Tudor wrote:Mention of 3 inch pieces though, why split those at all? Once you get a few smaller pieces going hot you can drop 1 or 2 pieces at 3 inch thickness in and you are set for a while right? I'm hoping so as my goal is to grow an acre or two of coppice to rotate through, cutting it at around 3 inches so I don't have to split it, just cut it at 15 inch lengths and it's done. But maybe that won't work, I haven't given it a try.

Hi Mark,
 You are correct, 3" pieces are fine.  The early stages of my RMH was a much more finicky animal.
For me, thicker pieces can slow the burn down a bit, so I  generally intermingle some smaller pieces or really burnable pallet wood.  
Staci

Having some fun.

Very cool! Just be careful with delicate detail like those exposed tree roots; unless thoroughly worked into the base cob, they will be easy to knock off.

Stacie;  That looks great ! Its about time you got to play with cob instead of just working with it.

How is your dragon burning ?  Any issues, or did they clear up as the cob dried out ?

That was great you got to stay warm ,cook dinner and hang with your family that stormy day!

Hi,
 Update and 2 questions.
  My artistry, while fun, is now crackly and crumbly.  Doing my best to repair.  Not sure if it will make the cut.  As someone suggested earlier, it would have been better to do the sculpting with the final straw cob layer, for strength.  (I learn the hard way ;)  I am not sure how the plaster layer will go on over all this.  I have been doing some reading on earthen plaster and realize it is worse than cob!  More testing, more ingredients (manure, wheatpaste, cattail fluff- oh my!) , ahh!! The fun continues...

Questions:

 1) In our area, tiny house ants are very prevalent.  Sometimes called "sugar ants", sometimes "piss ants".  They invade the kitchen and a few other places in the warmer months.  We try to control with Boxax or commercial Borax solution (Terro), it is all about control and never elimination, as they always return.  They have been gone for the winter until recently when I have noticed them crawling on the RMH: bench and manifold.  I guess they are liking the cozy warmth.  Anyone have any similar experiences?  ANy thoughts of control? I am worried that they will be setting up shop in the RMH.

  2)Wood woes.  While my little RMH is doing great and burning well, I am still unable to burn un-round pieces without smoking.  The flames creep up the piece all the way to the top and then it creates smoke.  I have tried cutting them shorter, thinner; turning them which way and that, making wide space between them, butting them up to the burn tunnel...nothing. Even the pallet wood does this (not round).
Draw seems strong, but I guess not strong enough. Sometimes I will shove a brick over the top to block the flames.  However, any way about it results in smoky air and constant babysitting. (round pieces are pretty much self feeding and I only have to add more).
  I am currently going through my wood supply at a fairly good clip.  Small rounds are nearing depletion.  I have many larger rounds remaining, but they will need splitting (too wide to fit in my feed door), hence the concern.

Good news, we have been hit with big winds.  I am going to work on collecting fallen branches for wood- great little rounds, but still green- so not for now.

Thanks!
Staci