Adding a bell/bench to the flue path of a standard box stove

[patamos]

I have a (barely educated) feeling that going two bricks wide will make for too long a flywheel with such a low powered fire chamber. I imagine your stove is much like my buddy's metal box with soapstone. Still designed to have a fairly slow gradual burn.

As a point of reference, last year i built a 6.5" J-feed with a large bench bell. It was entirely masonry and i made some areas intentionally thin so they would radiate heat sooner than later.  I built many of the vertical sections with bricks on edge (2.5") then covered in 1" of cob. For the bell bench top i used 2" thick concrete slabs with 1/2" cobb underside and 1.5" cob over top.
From a cold (room temp) start it takes a few hours for the heat to start coming through. So, my guess is that your bricks double wide at 7-9" will be too much.

Wondering/curious what the more seasoned builders have to say  ?  

[DCish]

I'm actually hoping for a nice long flywheel effect, as the stove will simmer for a long while, so no additional heat needed during that time. Currently I load the stove at night and have to build a new fire in the morning. What I'm hoping for is to load the stove at night and have the bench soak up enough heat to get me more or less through the next morning. However, I'd be very much interested in hearing feedback from more experienced folks.

[DCish]

Also, any recommendations for ratios for clay:sand for hole filling and mortaring bricks together?

[DCish]

Ok, dry-stacked mockup done. Next step: sourcing some clay, removing carpet, building bench, adding tile around bench as buffer between bench and carpet, topping bench with a 64" x 32" piece of slate a guy has lying in his yard.

Clay is a problem, Lowes and Home Depot don't stock it in this area, and no close-by pottery places that I've found yet. Dug some out of my yard, but made a heck of a mess doing so, hard to put back together again... don't quite live in the right area for excavating much. Any DC-area folks have good fire clay sourcing?

Another fly in the ointment is the brick... stored in a guy's shed, nested on by squirrels. Stinky. Washed them, dunked them in enzymatic cleaner that claims to get even skunk odor out. We'll see, it better work, too much effort for it to fail... (says it should stop smelling when fully dry. Roasting a brick now to test).

Ideas / critiques welcome before I start the final build (likely after the holidays)!

[Daryl]

If you find a good mortar mix, then please post it. Did you get the smell out of the brick?

[Daryl]

For basic dirt or clay, try the greenhouses, big box stores, or masonry suppliers. In my experience, the cheap dirt for sale is made up of a lot of clay. But do your research to check first.  I only build outdoors so the quality of the product isn't high on my list.

[DCish]

Dec 17, 2014 0:46:53 GMT -8 Daryl said:

Did you get the smell out of the brick?

Last night's test was a success... As advertised, once dry the Odormute treated brick no longer smells. Whew

[ericvw]

Now, your sure u won't offend any squirrel lovers who mite feel you're being unfair toward their excretions(pissin' squirrels that is!)
That sure is a load of bricks to de-piss, tho! Are there no stove or fireplace retail stores that carry regular ol' fireclay near you? One local hardware store here had unmarked sacks for $20 @ 50 lbs. a concrete and block supplier an hour away had it for $10/50 lbs. I know how costs can add up, but hey- u got the bricks either for a squirrel's song or free, so... But then again I don't know how much Odormute costs, either!
Anyway, the mock up looks good... Have you considered a clay slip? What if the thing doesn't do what you want? I guess the bricks will clean up pretty easily? I do hope you have success!!!
Keep us all informed, eh?
Eric VW

[2tranceform]

Dec 16, 2014 20:43:59 GMT -8 DCish said:

Ok, dry-stacked mockup done. Next step: sourcing some clay, removing carpet, building bench, adding tile around bench as buffer between bench and carpet, topping bench with a 64" x 32" piece of slate a guy has lying in his yard.

Clay is a problem, Lowes and Home Depot don't stock it in this area, and no close-by pottery places that I've found yet. Dug some out of my yard, but made a heck of a mess doing so, hard to put back together again... don't quite live in the right area for excavating much. Any DC-area folks have good fire clay sourcing?

Another fly in the ointment is the brick... stored in a guy's shed, nested on by squirrels. Stinky. Washed them, dunked them in enzymatic cleaner that claims to get even skunk odor out. We'll see, it better work, too much effort for it to fail... (says it should stop smelling when fully dry. Roasting a brick now to test).

Good thing you were able to remove the fly from your ointment. I tried unsuccessfully to source clay from the big box stores. It is listed on the websites, but it not stocked in my region. I called the masonry supplier and I had to explain to them what I was looking for. Strike two. I did find some clay nearby. Hopefully, you can find some clay nearby as well. Maybe talk with a home builder. This is a bad time of year to start a home build though. Good luck.

[DCish]

Thx Eric and 2trance. Guess I have some more calling around to do on the clay. The odormute was $15, so not bad compared to buying that much brick. Soaking it all was a total pain, though, I can vouch for that! I'm still a little nervous, it still reeks a bit, but... Oh well. Maybe a skim coat in the end would help out...

[DCish]

Ok, making some progress, pics to come. For now, how high off the floor should my plunger tube be for there to be no restriction? Is 3.75" (height of one brick on edge) enough? Here's the layout (bottom of inlet tee is 5" above floor):

[geri]

I've been following your posts. great idea. I'm thinking of piggybacking on what you are doing. Do you think this would still work if i used single wall pipe?
Thank you

[DCish]

Thx, Geri. Well, the first step is to see if this version even works! I'm getting close, hope to be done and able to test by the end of this weekend. Feeling hopeful but nervous (I'll give it about an 85-90% probability of working as planned, but there is always that last 10-15%...).

The use of double-wall is a decision made because of small children running around the house, plus trying to keep things nominally to building code. The only difference that I can see coming into play using single-wall is that you would shed more heat from the flue pipe, which would mean more instant heat and less left over for capture in the thermal mass.

[geri]

can't wait to see how it goes DCish. i set up my wood stove temporarily today. i just needed to get some heat going until i finish the wall that will be behind it. great timing. Thank you for sharing your experience.

[jkirk3279]

Wow.


This is similar to the question I was about to ask Peter.

We have a woodburner at our business, and in the miserable cold it can’t keep up. Last year we got by with firing pine scraps.

I think I may have burned 900 pounds of kiln-dried scrap per week last February.

The stove had to be kept clamped down, with a big fan blowing on the 8” flue pipe to keep it from overheating.

There’s no paint left on the single-wall.

But we WERE warm !

Unfortunately that free scrap wood is no longer available.

I was wondering if I built a three-barrel vertical bell, and tagged it in on the bottom of the cleanout “T”...

I have a blower from a pellet stove, and could rig that on the output of the smoke bell.

Flip the switch, close the damper, and the hot exhaust would flow up an inner riser, crown at the top of the third barrel and come back down.

Once established, I don’t think I’d need to run the exhaust blower.

I was hoping someone had already done this, so I could estimate how much efficiency would be gained.


The smoke bell would add mass, absorb heat, and the added surface area would mean that heat would be far more likely to radiate to the room than flow up the chimney.

I was only worried about cooling the exhaust too far, and breaking the draft.