The RMH Builders guide build-pic heavy

Eric Hammond wrote:The one other thing I wanted to mention....reading through this topic and through Staci's build, both Satamax and Staci have mentioned that they find feeding the beast finicky/requires a lot of attention.

I have not found this to be the case with me at all.  In fact right before it was mentioned in Staci's post I had loaded the stove up and went to take a hot bath, while thinking in the tub I was wondering "Why did Satamax say these things required constant attention?"  I basically filled mine up and walked away.  I wonder if its a difference between 6" and 8"?

Here is how it's going for me.

Hi Eric,
I am so glad is burns so easily! (Give you more time to cuddle that new baby!!)

I can usually get it up and running fairly quick, however,
"finicky" for me:
  I am constantly moving, poking, rearranging.  If I fill too full, it will smoke.  If something burns down and the load shifts, it will smoke. If the pieces I use are too long (I have many), it smokes.  If the pieces are not round and more angle, it smokes.   I generally am checking on it, eyeing on it from across the way (for smoke) every five minutes or so.  I have taken to NOT filling up the box, and maintaining space between the wood (not recommended, I know) to prevent the smoke.
 I do think 6 vs 8" has something to do with it. And wet cob.

I too have found that the bench has a voracious appetite for rocks.  I need to go ahunting today for more.
Cold cob mixing is not fun.  I was using bare feet, but switched to boots, because of the painful cold.    Not quite the temp. that you have, so I can imagine "not pleasant".

Looking good so far!!

Staci Kopcha wrote:
"finicky" for me:
  I am constantly moving, poking, rearranging.  If I fill too full, it will smoke.  If something burns down and the load shifts, it will smoke. If the pieces I use are too long (I have many), it smokes.  If the pieces are not round and more angle, it smokes.   I generally am checking on it, eyeing on it from across the way (for smoke) every five minutes or so.  I have taken to NOT filling up the box, and maintaining space between the wood (not recommended, I know) to prevent the smoke.
 I do think 6 vs 8" has something to do with it. And wet cob.

Staci,  It seems that in the early days of rocket stove development, a "feed barrel" with a lid (bung hole left open) was sometimes put around the feed tube to help contain any stray smoke giving it a second chance to get sucked back in without entering the house. Paul Wheaton had also experimented with what he called the "bubble" around the feed tube to help with this as well. It doesn't seem to be used very much anymore though as it was either considered unnecessary in a properly functioning unit or as a possible competing chimney. Hopefully your unit will not have this issue for too much longer but something to consider experimenting with if you want to step away for more than 5 minutes.

HOORAH!  HIP HIP HORRAAAY!!!  I have hit the JACKPOT!!!   ROCKET MASS HEATER JACKPOT I TELL YA!!!

I was searching around on craigslist in the free section and found a post advertising free wood, and the size of the wood in the picture looked correct for what I need.   There was an address so I looked it up on google and found out they make church furniture.  Every piece of church furniture I ever saw was oak.

I loaded up the trailer and this is what I discovered.



It's 90 percent oak with some ash mixed in.  Did I mentioned its all FREEEEEEEEEEEEEEEE!

Here's what the pile looks like





Some of it is quite small and will be great for kindling!




This is how much I brought home, That's an 18 foot trailer



This is where I was storing wood.....I had a nicely stretched out tarp, but alas the wind destroyed it





My pile was already starting to dwindle



I set up a workstation for chopping up wood to usable lengths, and now I'm storing it IN the shed because its dry in there and my wood is bug free!



After 3 FULL wheel barrel fulls, I barely made a dent in what was loaded in the truck!



Some of it is really decent sized pieces of oak!



The guys at the place, said that pile has been there for years and will only continue to grow.  I have an unlimited supply of great sized oak!!!  HOOOOORAH!

Awesome score, Eric!  That sounds like it will be an ongoing resource for you too!  It reminds me of the free scrap I used to see at a place that made moldings back when I used to do some woodworking.  I may need to look into that myself as it does seem like a fabulous source for easy kindling if nothing else.

I did my inaugural test burn in my rocket mass heater this evening.  It was fantastic!  It lit up beautifully and easily, with a solid draft pulling all the smoke into the burn chamber.  I am amazed at how much heat the little amount of wood I burned put out!  For a cold start in my old wood stove it would have just been barely warming things up.  I decided not to do a long burn thinking it might be easier on the wet cob/mortar sections to more slowly evaporate out the moisture.  I did get some cracking in the cob laid down yesterday to seal my barrel down.  I'm not surprised as I had a hard time envisioning that not cracking as the barrel heated up.  I can't wait to see how this goes once I add the pea gravel mass to the system!

Also check such places for plainsong shavings and sawdust These hard woof materials are most excellent for worm composting  in my experience.

David Huang wrote:Awesome score, Eric!  That sounds like it will be an ongoing resource for you too!  It reminds me of the free scrap I used to see at a place that made moldings back when I used to do some woodworking.  I may need to look into that myself as it does seem like a fabulous source for easy kindling if nothing else.

I did my inaugural test burn in my rocket mass heater this evening.  It was fantastic!  It lit up beautifully and easily, with a solid draft pulling all the smoke into the burn chamber.  I am amazed at how much heat the little amount of wood I burned put out!  For a cold start in my old wood stove it would have just been barely warming things up.  I decided not to do a long burn thinking it might be easier on the wet cob/mortar sections to more slowly evaporate out the moisture.  I did get some cracking in the cob laid down yesterday to seal my barrel down.  I'm not surprised as I had a hard time envisioning that not cracking as the barrel heated up.  I can't wait to see how this goes once I add the pea gravel mass to the system!

That's awesome David! I'm super happy for you!  We need lots of pictures!!! The more the better!  I'm starting to understand why Paul wants to spread the message of rmh far and wide!

Hans Quistorff wrote:Also check such places for plainsong shavings and sawdust These hard woof materials are most excellent for worm composting  in my experience.

This is news to me...sawdust for worms? I'll check it out!

I didn't take many pictures while building mine, but I'll try to share a few here.  This is my first time attempting to post a photo here so we'll see how this goes.

Well, posting that photo seemed to work so let me share a couple more.

Here's one final image I took by putting my camera down into the burn chamber so I could see what was happening.  This is as far in as I could reach on my 6 inch system to clean out ash.  Next it would seem that I need to figure out some sort of clean out tool to make so I can get all the way back.  Is there something readily available most other people use that I don't know about?  Fortunately for me I'm a metalsmith by trade so designing and making something shouldn't be too difficult, but I'm wondering how others deal with this issue?

David Huang wrote:Here's one final image I took by putting my camera down into the burn chamber so I could see what was happening.  This is as far in as I could reach on my 6 inch system to clean out ash.  Next it would seem that I need to figure out some sort of clean out tool to make so I can get all the way back.  Is there something readily available most other people use that I don't know about?  Fortunately for me I'm a metalsmith by trade so designing and making something shouldn't be too difficult, but I'm wondering how others deal with this issue?

Hi David- great pictures and work!!'
I am currently using an old cat food can and stretching my arm as far as I can.  I find that if I do more than one burn in a day, red coals are still there, making the metal can a red hot can. So then I interchange with an altoids tin. Real high-tech here ;)
Would also love to know if anyone has ideas on this!

Staci

Thanks Staci.  If I remember correctly from your thread, which I've enjoyed also by the way, you have a 6 inch system as well.  I'm guessing that an 8 inch system is easier to reach into, and those of us with 6 inch ones struggle more.  

Anyway, I had let mine cool down and reached in with a rectangular plastic lid from a box of screws that was handy at the time.  I still couldn't get all the way back.  The entrepreneur in me smells an opportunity here for a niche product!  Hopefully tomorrow I'll get time to cobble something together quick that can work better.  I'll share a photo if I succeed.  

I've been using a cut up Busch light can that was required for the building of the heater.  Like staci said, don't use with hot coals!  I would like to purchase one of those ash vacuums/shop vacs, but it also has to be really cool to use.

Hi Guys;
To make an ash scraper, You start with a piece of flat metal slightly narrower than your burn tunnel. So say 5" wide for a 6" system , 7" for an 8" system . It should be apx. 2-4" tall.
So for your 6" rocket)  flat metal any thickness you like 5" wide no more than 2-3 " tall. Drill a hole 1/4" directly in the center.
Round rod or all thread , 1/4" dia (or what you have)   8-10"  long welded or bolted to the center of your flat plate.  Easy to reach to the far wall of the riser and scrape ash to where you can scoop it out.
I put on a welding glove and just reach in the feed tube with a short piece of cardboard and scoop it out. I have a metal bucket that I fill to take out to icy spots on the driveway.

I should mention you could build this same scraper entirely out of wood and it would just work fine.  

For those not inclined to metalworking, I suggest the $1 or less option: take a fly swatter, bend it just below the "swatting" head so it's almost a 90 degree angle, and you're done! Insert it upside down so it slides along the top (to avoid pushing the ash further in), and when you feel it reach the heat riser you rotate it 180 degrees and pull it back out. The plastic is soft enough that you will never damage any softer materials like refractory board or insulating firebrick, and will get most of the ash out very easily without you needing to reach very far in. I have rather large hands, so a handled tool would work a lot better than just cutting a piece of cardboard and taping it into the shape of a scoop and reaching towards the back to pull out the ash (which is the free option).

I knew someone had to have come up with some brilliantly simple solutions to the clean out problem.  Thanks for all the responses.  If I had thought to get on-line and look this morning before I went out and made mine I probably would have tried something like you suggested Thomas.  Mark's solution is great too.  I especially like the idea of something soft that won't damage the interior of the burn tunnel.  My concern would be melting of the flyswatter if it hits hot coals.  This makes me think that an ideal solution might be a variation on both.  Use the basic form Thomas is suggesting, but instead of the metal plate get some sort of sheet of semi rigid silicone to use instead.  I'm not sure such a thing exists, but it seems like I've read about silicone sheets used for baking on in the oven.

Anyway, my professional pride has me hesitating to show this due to how crude it is, but this is what I threw together this morning out of some scrap copper.  It seems to work though I may tweak the angles of the bends a bit yet.

[sarcasm]Yeah, that looks pretty crude there David.[/sarcasm]

Seriously though, that is impressive. How much you selling them for?

Ha Caleb , I was thinking the same thing... CRUDE ha ha I could show you crude...

New buisness for you David !  It is very nice work.

I have been thinking on all the suggestions for ash scraper's.   My old rmh is all brick, nothing can hurt it. My new rmh is ceramic board  , If brutal enough I could hurt it...at least with steel. The flyswatter sounds like a great short term tool but...
Now I'm thinking of a piece of rubber tire to use as a scraper.  soft enough to not dig in to CF board , tough enough to laugh at small coals ???  Could be a winner !

Maybe I should have my own business to compete with David's !  Competition is good for business Right ?  

I think I am seeing round pipes to carry the gases through the benches. Aprovecho say to maximize heat transfer one should switch to using rectangular profiles. So round is on account of easier build? And any reason stratification chambers aren't being used?

David Huang, you're a poser

Graham Chiu, this was not for you!