The RMH Builders guide build-pic heavy

Eric, i like the side plenum with the pipe. Obviously not the first time i see it.

But i like it


You were stating about your burn tunnel being a smidge too high. But you didn't account for the P channel overhang down! Which would make it perfect.

and,

https://www.harborfreight.com/7-in-segmented-dry-cut-diamond-blade-for-masonry-68883.html

Hey Satamax. (Edited to correct your name, so sorry) My burn tunnel is the opposite a touch too short. The plans call for 7 by 7.5 inches and I have 6.5 by 7.5 inches.


I don't understand what this p channel is that you speak of. Could you please elaborate?

Here ya go!

Hi Eric;  Not sure what max was referring to but here is my P channel  (named for peter Berg the inventor) It extends apx 1/4" below your burn tunnel roof . Allows fresh cooler air in and creates a turbulence in the air flow ,  combine this with a Trip wire built in to a roof brick further down the tunnel roof and you will get the optimum burn pattern for a J tube.

Ok I understand the channel. What do you mean by a trip wire?

I don't have one myself but a trip wire is )  not a wire but a notch cut into a roof brick apx 2/3 of the way to the riser (i think)  changes the gas flow.  I'll check my book to see if I can find more info for you.  Try searching here on permies for it , I know there have been posts about it.

Try this,   https://permies.com/t/60402/channel-explain

My neighbor invented something similar for his L shaped rocket cook stove.  He puts a piece of 3/4 black iron pipe inside the wood feed with a 90 fitting the end.  Says it runs better that way.  The guys never seen the internet so it's interesting how people can come up with the same ideas on different ends of the world.

I went to weld everything together today.......what a disaster

I marked everything and ground all the paint off of the areas to be welded





Using my scrap barrel as a bench, I tack welded everything in place



That's when everything went to hell.

I first tried mig welding it.  I kept blowing holes through the 8 inch pipe no matter what I did.  Then I tried oxy acetylene welding it.  That was working fine, but taking FOREVER.

I decided to try brazing it to see what would happen.  Worked AWESOME!  I wish I would have went straight for brazing.  The braze flowed perfect.



I brazed inside and out, the hardest part was patching all the holes I made with the welder.... uhg



Cut out the pipe and the ground it smooth



Mocked up



Pictures of the transition

May I ask for some opinions of the exhaust tubing through the bench?  The book says for an 8 inch system, the max is 50 feet of horizontal tubing.  Subtract 5 feet for each 90 and if your exhaust flue pipe is next to the barrel and mostly inside you can add back 10 feet.  

The way I have this mocked up, I have about 30 feet of horizontal pipe.  I have 5  "90's"  So that puts me at 55 feet.  

My intended exhaust flue pipe is not super close the barrel, about 20 inches away, but will stay inside the building and heated area for 14.5 feet before exiting the roof.   The ridgeline of the roof is about 17 feet, so I will need probably 5-6 feet out in the cold exterior temperatures to get 2 feet higher then the peak.

Do you think this is too much horizontal to draft well and be reliable?  Should I reduce it's length?

Here's some general pictures

I'm using a 90 to sort of step down out of the barrel so that there will be plenty of a gap to the top of the bench to prevent overheating the top.  I did NOT figure this 90 into the calculation for feet of ducting because it doesn't change the direction of the flow really.  Perhaps I should?







Please tell me what you think about the overall length and layout.  I intend to put a "T" into the pipe upward to the roof and use black fireplace pipe, so its really just a rough mockup....

It's comming out good and clean, can't wait to see the finishing

In this pic, get rid of the end elbow, put two T face to face, so there is the opening of the T in line with the tube. That would help you clean the tubes.

In this pic,



I hope the T will come between chimney's elbow, and tube, for cleaning. That would be good practice, also can act as a primer. To light a little fire, to warm the chimney.

Also, it would be good practice to  put a t again, on the next tube exiting the barrel.  to clean the first length easily. And you could bypass the bench temporarily between the two, to warm the chimney again.

I think 55 is a smidge much; Why don't you cut the two end of the bench tubes a bit, so you're perfect?

On the side that makes the 180, I had intended to make the bench all the way to the wall. I'm envisioning leaning up against the wall sitting on the bench with a book and then laying down to take a nap.

In it's current configuration the tee is about 18 inches from the wall. I could shorten each tube 2 foot and be at 51. Would it be too much bench to be built up to the wall with no pipe in it that far?  That's a strange sounding question.  Basically do I have to shorten the bench if I make those pipes shorter or is it ok to have a bench with no pipes in part?  That's why i did the tee plus the 90, because i didn't envision having access to that side for cleaning.

I'm not sure how much cleaning is required in the tubes, but what I had in mind was just using a fishtape for pulling electrical  wires and pulling a brush through.

Well, i would shorten the bench ,and make a wooden stool to finish it to the wall, covering those tho T

You need to clean.

https://permies.com/t/63909/RMH-diagnosis

https://permies.com/t/58540/clean-works-didn-work

I'll go ahead and shorten the bench a bit like you say.

Today I decided I was going to burn off all the paint from my barrels.

I set the green barrel up on 3 fire bricks to allow some air underneath and filled it full of a couple old branchs





This got freakishly hot quick.  The paint started smoking off the barrel.



Then it started to turn black



and then the outside spontaneously caught on fire....



I started burning the bottom section when the fire was ridiculous



Moved everything around and burnt the lid off



I took the lid off and set it on the ground, the ground immediately caught on fire



The key to all this was when it was good and hot, I blasted it with the water hose.  This shocked it enough that every bit of paint just shot right off.  Although a good hot fire helped too.  Even though I'm hitting it with water, you can see the bottom of the barrel is still orange....



This is what the hose did, compared to the paint you still see on the left side that hasn't been hit with water yet.



The whole process of burning the barrels went super quick, like 30 minutes tops, including cutting all the wood.

I had it in my mind I was going to paint the barrel with hightemp paint, but I estimated I would need about 60 dollars worth to do it right with primer and everything.  I opted to just cover it with coconut oil(free and didn't use very much at all), which I'm glad I did because it was a major time saver.  I coated the whole thing and was done in 5 minutes.  If I painted that it would have taken me hours

Finished barrels

I will try to remember that.

Fascinating project. Amazing fabrication skills too. Creating the joint between the barrel and the stovepipe and getting it welded up up satisfactory, WOW. That is no simple task , and especially feel for you when you started to realize the hard work of cutting it out properly was in peril because of the difficulty welding thin gauge metal. Congratulations this is so encouraging. I'm av\idly following along.
Brian

Thanks for the kind words Brian. I used to be part of a machinist forum, we would do step by step builds in our own thread until we had a completed engine and I really enjoyed that process.  I thought I would try it on this forum.  I was hesitant will all the pictures, some people hate that.

Progress is going to slow for a bit, I have a 4 day  conference in Dallas to go to tomorrow and then I will be back for 2 days before leaving again for another 3 day conference.  I've ordered the insulation and stove gaskets and they should get here while I'm away.

Eric Hammond wrote:Thanks for the kind words Brian.

You are most welcome Eric. I have been here a few years, during a very difficult time in my life. Illness has kept me from doing my projects. I hope I'm surfacing now and and able again to build the things that made me feel proud and happy for decades. Your build is so very encouraging for me, thank you!

Eric Hammond wrote:I used to be part of a machinist forum, we would do step by step builds in our own thread until we had a completed engine and I really enjoyed that process.  I thought I would try it on this forum.  I was hesitant will all the pictures, some people hate that.

Progress is going to slow for a bit, I have a 4 day  conference in Dallas to go to tomorrow and then I will be back for 2 days before leaving again for another 3 day conference.  I've ordered the insulation and stove gaskets and they should get here while I'm away.

Yes I agree, the step by step method is very helpful for those of us that may wish to reproduce a similar build. I only wish I had more to offer, than praise. We had a rocket stove workshop here at our homestead in northern New Mexico several years ago, that's about it on what I knew before your project. The detail you provide is outstanding for mechanically-minded folks such as myself.
Brian

Hi Eric,
  I just found your thread last night and have been reading/looking through it.  VERY insightful and helpful.  I am kind of in a similar situation, I wanted to install a RMH last winter, but time got away and decided to do it this summer. However, I am still at zero progress (other than supply gathering).  I a m going with a 6" system from Ernie and Erica and plan to do it "by the book".  It is for an existing brick floored buildout with  no heat- kids play room.  We have relied on space heaters for 10 years.  We live near Tacoma, WA.   I am a stay at mom with 4 kids and have no "shop skills" (life science was my field of study/work).  My husband is a bit more handy, but works full time.
 I planned to go with a firebrick riser wrapped in rock wool insulation.  I salvaged firebrick, but have no 1/2 (split).  I found light kiln brick for a decent price, but now read that using heavy for the burn tunnel and light for the riser may cause a problem.  We have no torches or welding stuff, so I was planning on going with a brick manifold.    Anyways, it is nearly August and still ground zero.  I am petrified and frozen to move forward.  2 kids are at camp next week, so maybe can...start.
ANYWAYS- I appreciate your posts and may have to pick your brain on occaision.  THANKS! Staci