Updated NH RMH build w/PICS!!!

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Updated NH RMH build w/PICS!!!

Postby rjdudley » Sun Aug 04, 2013 5:57 pm

Sorry for not posting for a little while, but, I've been trying to gather components to finally start piecing this thing to together. The duct work has been a beast!. Nothing seemed to fit easily, when trying to attach one part another would come apart until finally I just started taping each section as I went along.
Then I went to build my heat riser and after cutting the outer pipe I had just purchased I realized something was off. The 14" pipe they sold me was actually only a 10" pipe. Crap.
While I'm on the subject of the heat riser, Matt if the outer pipe is 14" and the 55 gal. barrel measures 23" that makes for 4.5" gap all around the heat riser. Is that too much? Ianto calls for 1/5 − 2". My guess is that it won't matter and it's probably better to be larger than smaller.
Anyway, here are some pictures:

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Manny, I don't think we'll be using the rough sawn on the front. Our reasoning is that we think it would hinder the heat release and force the heat through the top of the bench only instead of from the front AND the top. Any feedback?
Ray
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Re: Updated NH RMH build w/PICS!!!

Postby mannytheseacow » Sun Aug 04, 2013 8:31 pm

Dang, those are some nice looking walls, Ray! Very clean looking build, too! I'm new at these things, too, so I don't have much input on what's right or wrong. Ultimately you know your house, climate, insulation, heating needs, etc., best. I love the look of rough sawn lumber if if its not right for this situation then that's just how it is.

I opted for more clean outs, and in more need-accessible locations. One thought I have is that the clean out by the exit flue might be better if you just fitted a T straight back to the vertical exit rather than doing that wrap around.

I'm really liking that 8" system and still wish I could have configured that size into my place. I've been slowly trucking away at my build- got the sensors all wired up to the controller and pumps and put another thin layer of cob on my bench. My heater is operational now, just needs the finishing touches, and a little cold weather. It won't be long and you'll be in the same boat with yours! Thanks for posting the update; I'm excited watching your progress!
"Knowledge is power. Arm yourself."
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Re: Updated NH RMH build w/PICS!!!

Postby matt walker » Sun Aug 04, 2013 8:48 pm

Looks really good Ray. I recommend a clean out T at the first 180, but other wise it looks great. Like Manny said, you could go from that last clean out straight back to the chimney, but if that works with your layout you may get a bit more mass heating keeping the 180 you have there. It is great to see your progress, thanks for the update.
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Re: Updated NH RMH build w/PICS!!!

Postby rjdudley » Mon Aug 05, 2013 1:28 am

Ah, there's no comfort like the voices of experience. The only reason we had for the additional 180˚ bend at the end was that we were hoping for a few more extra feet of run. But, I like the idea of putting the tee there and ending at the tee. I'm sure the cob at the end will still get plenty of heat.
We will also be bowing to the voice of experience and placing another clean out at the first 180˚ bend.
Matt, did you get to think about the question I had concerning having 4.5" of clearance between the heat riser and the barrel?
I'm caught between a) it's a good thing because more hot gases can travel through, and b) it's not a good thing because the wider space could mean faster cooling.
Tomorrow, Monday, we begin cobbing! We're going to build the first 4 inches of base using the cob and then placing the exhaust piping into place. I'll be burning off my 55 gal. drum tomorrow as well. Big day at the Dudley Homestead!!!
Ray
Last edited by rjdudley on Mon Aug 05, 2013 11:43 am, edited 1 time in total.
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Re: Updated NH RMH build w/PICS!!!

Postby mannytheseacow » Mon Aug 05, 2013 2:22 am

I have a total of 4 clean outs in mine. At the end of the long run where the tubes do a 180 I put two in, side by side. This might be overkill but I know in my old wood stove how nice it was to be able to run a pipe-brush or vacuum hose straight through the whole line. Even if I didn't have any creosote I just like knowing it's clean.

I remember Ianto talking about 1.5-2" clearance with the heat riser but that is from the top of the heat riser to the top of the outer barrel (inside). I've never read anything about the sidewall clearance. I'd be curious if it matters because I'm running a 12" riser in a 23 " barrel, too. I think those are common dimensions, though.
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Re: Updated NH RMH build w/PICS!!!

Postby matt walker » Mon Aug 05, 2013 2:38 am

In my opinion you can't have too much room in there Ray.
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Re: Updated NH RMH build w/PICS!!!

Postby rjdudley » Tue Aug 06, 2013 1:45 pm

OMG! What was I thinking? Cobbing is frickin' nuts!!
So we started cobbling the bench and it's wayyyyyyyyyy more labor intensive than I thought. Not prohibitively, but, dang I should've done this when I was younger.
A couple of more pix for everyone as we document our progress. This morning I noticed the cob we put down yesterday is cracking a bit. A good sign it's drying nicely. I also finished my heat riser yesterday. Matt, just and FYI, I used the proportions you mention in your video, but, fell really short. I was only able to fill about 3/4 using my 50# bag of refractory and perlite. I filled the last 1/4 with clay/perlite then topped the whole thing with cob. I hope that turns out to be ok.
Pictures:
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I posted the pictures of the burn chamber because I wanted you guys to see that I've coated it with some fireplace cement. I did that for two reasons: the texture of the refractory seems to be rather granular and I figured this would help hold it together better, and I also am hoping it provides more insulating. It may not add much more insulation due to the fact it's just a coating, but, anything is better than nothing. The bottom isn't coated because, truthfully, I'm nervous about moving the sucker!
Ray
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Re: Updated NH RMH build w/PICS!!!

Postby matt walker » Tue Aug 06, 2013 4:00 pm

Looking great there Ray. Dang, sorry the proportions I recommended didn't fill it up, I think you will be fine with what you have done though. If you come across more perlite before you assemble it it would be worth mixing up some into some cob and re doing that top 1/4, but I don't think it's a deal breaker. And yep, cobbing is a good work out for sure! Once those buckets start going in the house you will get a pretty good idea of MASS! Lol. I couldn't believe: A) How heavy the buckets full of mud were, and B) How many I brought in and put on my floor! :shock: Thanks for the pics Ray, you are making good progress there.
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Re: Updated NH RMH build w/PICS!!!

Postby rjdudley » Wed Aug 07, 2013 3:32 am

I'm having some real problems with figuring the the cob ratios. I've seen ratios of 70% sand to 30% clay and that's what we've been using, but, honestly I'm not sure it's right. You couldn't make cob balls out of the stuff and it seems too watery. Then I saw a guy that uses 2/3 clay to 1/3 sand and it looks like nice clay clumps. Any input here?
I know the sand is the "brick" and the clay is the "mortar", but, I may be too westernized and I'm thinking the "cob" should be something you kinda pull a clump off of and smack onto the surface.
Is that right? Or are there different types and different uses?
On another note, did a great burn for the heat riser and burn chamber. VERY happy with the results. A lot of ash, mainly due to the crappy wood I burned, but, man did it work great.
I did have one issue where the heat riser didn't sit tight on the burn chamber. Eventually I just put cob under it to seal it, but, did any of you guys have to do anything differently?
Ray
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Re: Updated NH RMH build w/PICS!!!

Postby mannytheseacow » Wed Aug 07, 2013 3:54 am

I'm a home brewer and one of my first rules in homebrewing when making a batch of homebrew is: "Relax and have a homebrew". I'm afraid this mantra has worn off into many other facets of my life! :lol:

I wasn't sure about this cob stuff when I started and I went to great lengths to find all these different "dirts" that I thought would be just right. The latest batches I've been mixing up have just been some crap that's easy to get to that I sift through a 1/2" screen to get the big rocks out, and then add a hand full or two of some chopped straw. This has been working great for me. Add some water.... maybe a little more water... (don't forget to relax and have a homebrew). It'll be ok.

Not to be candid, but seriously... the more you do it you'll figure it out. After all, it's just dirt! I've found adding the straw keeps it strong and tight when other proportions in the mix may be off.

Oh, and where my heat riser attaches to my burn chamber, I built my riser right onto my core, so it's been attached the whole time. I've smeared wet earth all over it in the process of building the bench though. I imagine you'll be fine. You could always smear some fireplace cement over it if you have some around.
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