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

Staci, i know you are following plans.

I just wanted to give you an option. Because i know that Diana Lee has had problems with cleanouts. And others too.

What happens, if the back tube gets clogged by fly ash, and your vacuum doesn't reach? Have you seen the size of your arm compared to the T and elbow on the pic? Well, anyway, you do whatever you want.  

thomas rubino wrote:Stacie;
I suggest a tarp outdoors to mix larger batches cob at a time.

Yes, I see that tarp is the way to go.  As the rains are coming early and strong this year (Western WA!), tarp may have to be indoors.
Mud in the house and some fancy footwork mixing cob!!

Satamax Antone wrote:Staci, i know you are following plans.

I just wanted to give you an option. Because i know that Diana Lee has had problems with cleanouts. And others too.

What happens, if the back tube gets clogged by fly ash, and your vacuum doesn't reach? Have you seen the size of your arm compared to the T and elbow on the pic? Well, anyway, you do whatever you want.  

Hi Satamax,
 Thank you for the feedback!  I am not at all dismissing your suggestion, and will turn my "t" orientation around, but just trying to understand it all.  Do you just shop-vac in the cleanouts??
Staci

Cob cracking!!?  About 12 hours later.

I did several test bricks and had zero cracking.  My mix was 1:1:1 dirt, fireclay, sand. The other lower clay mixes were all super crumbly and fragile.
I can try another mix, but now have little faith in "test brick" as the small brick does not behave the same.  My test brick was small, is that the problem?

Do I need to pull up the cracking cob and re do?

:(

No, don't back up not this deep in your mass. Use more sand in your mix. less dirt.   My clay was very pure , so is yours being fireclay. I needed 3 times the sand to clay mix to control cracking.  My barrel cob still develops cracks but that is more do to the metal barrel expanding and contracting.  
For your current cracks simply mix a batch of cob, sand heavy and wet, rub into your cracks to fill them. Then just carry on.
I don't remember are you planning on an exposed cob bench ? Or are you encasing it ?

Thanks, Thomas!  I will add an additional portion of sand to the next batch.  
Doing an exposed cob bench.  (I found your thread on dye/paint cob with natural minerals...but that is a ways off and will have to revisit.)

Off to harvest more dirt today,  and scored another free load of sand (Offer up) that I pick up tomorrow. Getting a bonus workout!

Played some more with cob; repaired cracks, increased sand and kept a rough texture.
Taking a step back and reading some more, I will re-focus on completing the manifold and burn unit, so this beast can be fired up and help with the bench cob drying.  

Immediate concerns:

 1) Husband does want not to look at the brick manifold, so I need to cob over.  I also need to cover the top of it (5 inches thick).  SHould this be thermal cob or structural cob or a layer of both?
 
 2)  If manifold is cobbed outside, should I still cob inside?

 3) Still concerned over my cleanout at the 180.  Satamax showed me that this is not the ideal position of the "T".  I was thinking that I could untape and then do a quick turn around of the T, but not so simple as it messes up the length of the pipes and I will have to cut/refit the run.  I can go through the hassle if it is best in the long run.

 4) And dumb question:   How do the pipes not get crushed when you sit on the bench?  I get that you build up the sides and space between the pipes first, and then cover, which then creates and "arch" of sorts and protects the pipes.  Is that all?

Thank you!

Staci Kopcha wrote:
 3) Still concerned over my cleanout at the 180.  Satamax showed me that this is not the ideal position of the "T".  I was thinking that I could untape and then do a quick turn around of the T, but not so simple as it messes up the length of the pipes and I will have to cut/refit the run.  I can go through the hassle if it is best in the long run.

 

Maybe I am misjudging this... I will untape, readjust and see what happens.

Hi Stacie;

#1) Both.
#2)  Yes , just a smoothing layer to direct the hot air to your pipes.
#3) If you can turn that cleanout it would be more convenient. If you can't, you can work with what you have.  If your rocket is built to spec and burning cleanly (good dry wood) you will not produce enough fly ash to go more than a few feet down your horizontal.  You have your cleanout at the manifold , the one at the 180, and your vertical leaving the mass is able to lift off.  It is enough. Mine has been burning for 5 years , I have one cleanout at the manifold I have none at my 180... (i really should have put one there) My vertical pipe IS able to lift off for emergency cleaning.... I have not yet needed to lift it.  At one point my stove was not built to spec...  seemed to burn good until middle of winter when it just wasn't rockety anymore.  Turns out I was not burning cleanly and produced enough ash  to partially plug my horizontal. Vacuuming cleaned up the visible run  ... that was when I learned that vacuums do not like fly ash... I also learned that using a leaf blower works much better, as long as you remember to remove the chimney cap first... ha ha
#4)  I wondered the same thing when I built. So as I came up with the cob I placed large flat rock over top of everything to distribute the weight over a larger area.  The cob itself is very strong when dry.

Last of all ) I recommend you watch the video just posted by Matt Walker about mortar making it is very informative!

Thomas, thank you!!  Will head all the advice.
I wish I could buy you a beer, nominate you to sainthood or something- your help is invaluable.

Ha Ha Stacie; Glad to help.  My wife would say I should pay you for allowing me to talk and talk. I talk to complete strangers about rocket stoves ...She is convinced they only listen out of politeness..  I have this foolish idea that anyone who burns wood, knows somebody who burns wood, has a grandmother who used to burn wood ... ALL those people NEED to hear about this ... and in my mind they will want too!   Mainstream america has no idea of the possibility!  Have I started rambling ? :)

Confounded Cob!!  It is a frustration.
My "cob" looks and feels like sticky beach sand.  Running my hands and feet through it feels like sandpaper...is this right??  I have cob-envy of all those lovely pictures of bright orange clay soil cob.
How do I go about cobbing a vertical wall?  I started wetting the bricks slightly, and then started added a smear of clay-slip.  It looks like a sandcastle and not beautiful "adobe-like" texture that I see in photos.

Stacie;
  Let it dry some, then use a wet hand & smooth it.  If you really think it is to sandy, mix a extra hand full of clay and add another layer ,you can't have to much. I found myself treating mine like concrete,  patting with my hand (jitterbug) until the "cream" comes to the top, then smoothing it about.  When its to wet, it has to dry some. Vertical walls can take a day or three to get to the top.  Gravity wins if you go to fast .
If you want your clay to look more orange , simply go to any hardware store and buy a box of red concrete dye. Its a small box, don't let it fool you... only add a little ,it goes a long way.  I had almost a pink looking cob for a few batches when I added to much.

Also don't forget you will add straw closer to the surface to make it stronger, but in the interior you can add large rocks and fill the gaps between them with cob, so you make less cob.

I am determined to master this cob thing.  I set up all manner of combinations, in addition to a "control" which is my current mix.  My science background at work!!
I am testing 1:3 mixes, with 1 part fire clay constant.  I set up as I would cob on my brick layer...will sit back and observe.

I got the "T" cleanout turned around, however the straight line is on the inside pipe instead of the outside...only way I wouldn't have to cut pipe.

This weekend: cut off barrel lid (my husband) and depaint rim. Insulate tower with rock wool. And cob.

rockwool insulation and wire...okay???

Maddening...none of my test cobs cracked. Not even the one-in-use which clearly cracks.
Tried larger batches last night.  Stuck some in the oven this morning to speed drying.

In photo:  "My sand" vs "utility sand" (builder's) side by side...my sand (left) has a bit more "sand" and less grit.

**Barrel question:  We burned the barrel last year and got some paint off.  My husband used an angle grinder to get the rest off.  The LID still has stuff around the inside groove. Also the locking rim is covered in paint.  Any ideas how to get it off?  Not so easy for the angle grinder.

Thanks!

Hi Stacie;
Your sand looks to be just fine. Almost better looking than the builders sand. What happened to the silica sand from the clay shop ?
Best way to get the rest of that paint off is to burn it.  Ideally you would toss them on the burn pile in your back yard...  I said ideally...  BUT being as your on the coast i'm guessing that is not an option.
Use a hand held propane torch . Won't smell too good, but outdoors as long as the neighbors aren't nearby, I think you can get it burned off.  Someone with an oxygen , acetylene torch could have it all done in 5 minutes.

OK, NOW THIS IS IMPORTANT !!! PAY ATTENTION !!!  DO NOT COB.... that cute little bunny inside your manifold ! :)

thomas rubino wrote:

OK, NOW THIS IS IMPORTANT !!! PAY ATTENTION !!!  DO NOT COB.... that cute little bunny inside your manifold !

Yep, better kill it before cooking it in the firebox, once the fire is out.

thomas rubino wrote:Hi Stacie;
Your sand looks to be just fine. Almost better looking than the builders sand. What happened to the silica sand from the clay shop ?
Best way to get the rest of that paint off is to burn it.  Ideally you would toss them on the burn pile in your back yard...  I said ideally...  BUT being as your on the coast i'm guessing that is not an option.
Use a hand held propane torch . Won't smell too good, but outdoors as long as the neighbors aren't nearby, I think you can get it burned off.  Someone with an oxygen , acetylene torch could have it all done in 5 minutes.

OK, NOW THIS IS IMPORTANT !!! PAY ATTENTION !!!  DO NOT COB.... that cute little bunny inside your manifold ! :)

Hi Thomas,
  The silica sand was in the mix AND the first one eliminated.  I did 1/3 clay, 2/3 sand and it barely held together.  

Hate to go buy a torch. Maybe I can find a loaner.  Burn season is at  close for now, so maybe we can do a burn in the yard.

Rabbit lost his manifold privledges after messing with the insulation. Capped all the ducts, and then he just hopped over and in, so now he is on free-roaming restriction.  :)  

Satamax Antone wrote:

thomas rubino wrote:

OK, NOW THIS IS IMPORTANT !!! PAY ATTENTION !!!  DO NOT COB.... that cute little bunny inside your manifold !

Yep, better kill it before cooking it in the firebox, once the fire is out.

My daughter would disown me.

Staci Kopcha wrote:

Satamax Antone wrote:

thomas rubino wrote:

OK, NOW THIS IS IMPORTANT !!! PAY ATTENTION !!!  DO NOT COB.... that cute little bunny inside your manifold !

Yep, better kill it before cooking it in the firebox, once the fire is out.

My daughter would disown me.

I killed my first rabbit when i was a kid, i was playing with a friend, my grand father wheeled hand cart and the little rabbit, that he just gave me. There was a big cobble stone, i did put the rabbit in the wooden crate of the cart, and pulled it with my little hands.  and then thought about something else, and let the cart go, which fell backwards. Because of the heavy weight of the cobble. Which in turn crushed the rabbit. I was shocked, but had to finish the poor animal, whacking it against the wall. To put an end to it's misery. I was kind of shocked. I was may be 6 or 7, that's 38 years ago, or so. I still remember it. But if you want to feed yourself with meat, you better start young.

A hand held propane torch with the screw on throw away bottle should be in any handyman's tool box.  I would think a neighbor might have one. I could find six or more around here. (big help that is)
Any auto type shop or backyard repair man should have an oxy/acy torch.(have one of those as well) One of those would take just moments to remove the paint. And I would think, most would be happy to do so for 5-10 bucks.

Alas no more free range bunny... your so mean to the little nipper .... LOL

Satamax Antone wrote:

Staci Kopcha wrote:

Satamax Antone wrote:

thomas rubino wrote:

OK, NOW THIS IS IMPORTANT !!! PAY ATTENTION !!!  DO NOT COB.... that cute little bunny inside your manifold !

Yep, better kill it before cooking it in the firebox, once the fire is out.

My daughter would disown me.

I killed my first rabbit when i was a kid, i was playing with a friend, my grand father wheeled hand cart and the little rabbit, that he just gave me. There was a big cobble stone, i did put the rabbit in the wooden crate of the cart, and pulled it with my little hands.  and then thought about something else, and let the cart go, which fell backwards. Because of the heavy weight of the cobble. Which in turn crushed the rabbit. I was shocked, but had to finish the poor animal, whacking it against the wall. To put an end to it's misery. I was kind of shocked. I was may be 6 or 7, that's 38 years ago, or so. I still remember it. But if you want to feed yourself with meat, you better start young.

That could set a fellow back a bit! But, honestly an early healthy exposure to realities of..."c'est la vie".  Kids of today are missing out.

Public Service Announcement for Newbie RMH Builders:

   When you order your Class A chimney and your class A chimney KIT, make sure they are of the SAME MANUFACTURER, or at least compatible (looking at exact measurements).
AND don't order and then wait an entire year prior to actually doing the project.
#burned.

is it something which can be solved with crimping pliers? Tin snips?

Satamax Antone wrote:is it something which can be solved with crimping pliers? Tin snips?

Not so much.  The cap doesn't fit on and can't see a way to make it work.  I want it to be "proper Chimney", code and all.
Flashing doesn't fit either...though I am not sure why one brand 's (Selkirk) 6" chimney pipe would be a different external diameter than the Duravent.
Attic insulation piece is not needed, as there is no attic, BUT I had to get a 12" chimney pipe section to get it the required 3 feet above the roof.

If you know of anyone in need of a Selkirk chimney kit, send them my way!! ;)

Got a second layer of cob inside the manifold.  It was a challenge: vertical walls and cobbing.  Language was not pretty and I was(am) nearly ready to get out the sledge hammer and go with a barrel manifold. (except no welding/metalwork tools or exp.)
It is separating from the brick at the top  I was holding off cobbing this, until it was time to set the barrel on as I didn't want to raise the barrel much above the brick.
If cracks appear, that may be my breaking point.  Not holding my breath...

Stacie;
I can almost promise you, it will have a seam crack . Put a layer of cob on top of your wall , let it set up , hand fill the inside seam. When in doubt ...Add More. Also you can add some straw to your mix to help hold it together. I wouldn't get carried away adding it but if your having a problem area it could help. Now that your  in the manifold area your heat is decreasing that straw should not burn up.
Figure out your barrel height. If you need too, add extra bricks to bring it up.  If you have any rock wool left, you could seat your barrel on it and cob over top of it. The fibers would help control the cracking.  
Do not overly stress about cracks . Your going to get some. Simply mix more sandy mud and fill them cracks up, then carry on.  I still keep a bucket with dry cob nearby, if I see a crack, simply add water re hydrate the cob  and rub it in.

I got another layer of cob inside the manifold.  (Good music is essential.  I had Nate Reuss serendading me with "Carry On", and so I did!)
Found a small torch from the neighbor to use on the lid rim.
Starting to cob the outside of the manifold.  Do I just cob around the firebox as well?
Having technical problems with my usual device, so unable to post pictures for now.

Yes , all around the core as well. I would use straw cob for that whole area. , You can pretty it up later.
Dang those newfangled devises and their technical problems !  

Oct. 1rst and NOT finished.  (heavy sigh)
Today I re-cut one bench pipe for chimney distance to fit. Planning on: adding another layer of cob/mass to the bench, adding 1" cob under the pipes, finish cob layer one around fuel feed, and add first layer of straw/cob to outside manifold.  

Questions:

1)  The area behind the manifold (in between manifold and wall) that contains the pipe to the chimney:  what do I do here?  Cob all round it?  Extend the manifold bricks to the wall and cob?  I am going to need a dump truck. (FYI: I have ceramic tiles that are going on that section of wall as a heat shield.  There is 6" clearance between per code.)

2)  Do I need to wait until the inside of the manifold is completely dry (to monitor/repair cracks) before seating the barrel?

3)  Barrel: barrel I got was roadside free.  We burned it and then angle grinded the remaining paint/rust.  It is now a sort of shiny silver.  I am debating whether to let it remain thus or paint it an even black.  (I found hi-temp grill/stove paint rated to 1200 degrees.)  Will the barrel "mellow out" in shine after using it?

4)  Building bench as I understand it:
      I have a layer of brick, added a layer of cob, added a layer of rocks.  Now I need to make sure I have a nice 1" layer of cob under ( and all around) the pipes. SO, I was going to do the under layer, then add more cob/rocks up on the sides until there is enough to support the 1" layer of cob on the sides of the ducts.  Continue.

I feel that I am moving in too many directions and not getting much done.

Thank you.

Hi Stacie;
I have good news for you...   its only September 30th ... gee my ears are suddenly burning ?? :)

#1) It looks like currently its just brick back there.  I would give it a layer of cob  just to know its sealed well and call it good. The pipe where it goes vertical should be in the 130 F range,more heat for the room .
#2) I would not wait, your only really worried about exhaust venting into the living area.  Any cracks you see on the outside should be fixed.
#3) I used flat black high heat paint on mine, works great. Of course 3/4 of my barrel is cobbed... Some folks use oil on bare steel and yes, it mellows the blinding bare metal look.
#4)Cob Lasagna ... layer mud, layer rock ... continue until full... yup you got it. You need your cob wet enough to fill all voids but try to limit just how wet it is, as every bit of water that goes in... will need to evaporate out ...

#5) Stacie;  You are doing AWESOME !  You are doing this almost all by yourself... DO you realize what an inspiration you are to hundreds of permies out there ?  A few have written in, but I assure you there are many more watching your entire build and in their head they are thinking "If she can do it so can I"
Remember.... Rome wasn't built in a day. It is all coming together and soon your going to be lighting up your dragon for the very first time!
Scary Scary but very EXCITING as well !

Oil the barrel, paint is bad for the health. Normally, barrel should blue on top, and further down with age.

Thank you, Thomas for the kind words!!  I needed that today.

Satamax-  that was my concern when I was reading the paint label in the store.
I'll get out the oil, and sunglasses until it mellows.

Staci,    One of those people Thomas was talking about is me - I am also enjoying your build as you progress along and learning as well.
One thing I can say is that I don't know how many times I have taken my stove apart to make major changes or just to tweak something that I want to try. Experience will teach and guide you all the way. Keep up the great work!!

Anthony Ryan wrote:Staci - Great post at an opportune time as we are just starting our 6" rocket stove working off the same drawing here down in New Zealand.
I was just about to order the fire bricks, yes was going to use full ones for the riser as well!
Following the response and threads;
1. I will look at a cast riser, or at least split bricks.
2. I had not thought much about the transition to the flue, this looks a key ash clearance area and the attached thread invaluable. good access ash pan and smooth chamber required.

Questions;

1. Are you going to introduce secondary air into riser tube? I have seen some information on this but no drawings, just comments on a sketch.
2. I intend to install water heating tubes around the main drum to run a wetback radiator system in the house. I have seen pics on this, are there any issues with cooling the drum that much? Does anyone have experience on this?

Cheers Anthony
Makahuri
Otaki
New Zealand

Hi Anthony,

I'm about to start my 6" system build too after an outdoor core build and learning some cob/clay mortar/clay slip stuff first.
I would suggest you stay away from the hot water thing until you have built this first. My understanding is that making hot water is one thing, running it through a radiator is another.
Given where you are, which is relatively mild, you may want to look at an air transfer kit which is a fan installed in the roof space linked to 1,2, or three other rooms and it pulls warm air from your heated room once the thermostat reaches a set temperature and dumps the heat into the unheated rooms. pretty low on energy (like between 60-120W depending on fan size).
That would be a much safer and more DIY friendly solution to heating other rooms.

Thanks
Dan

Blue Mountains
Australia

Okay, getting the cob thing down I believe, but I make a mess no matter what.
I had my son help me lift that bad boy over the tower yesterday. It is nothing short of ugly! ;)   Clearance was a bit less than 2", so I build up with a bit of cob and it looks good today.
Next step is cover the manifold.  I was going to do an under layer of thermal cob and then 5" of structural (straw) cob.  I am a bit wary of it collapsing in: I fitted some old hardware cloth.  I also have 2 metal scraps to use as support.  Would using them be a problem/disruptive to the air current under the barrel?

Thank you!!