Converting an old wood stove into a rocket mass heater

Discussion in 'Rocket Stoves & Rocket Mass Heaters' started by BrianK, Feb 10, 2018.

  1. BrianK

    BrianK

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    How to make a Batch Box Rocket Heater out of an old wood stove

    A couple weeks ago I started modifying a Vogelzang Frontiersman wood stove I found on Craigslist for $45. I simply used a Harbor Freight 7” angle grinder ($45 with coupon) and Metabo cutting disks to modify it.

    First I removed all the firebricks lining the wood stove and cut out the top, then the angle iron on the insides of the left, right and rear wood stove walls that previously held the firebricks in place.

    I’m left with an empty 21” wide x 17.5” deep by 15” tall rectangular steel box that I can use to hold my 6” or 8” rocket heater refractory core.

    This took less than an hour of light work to modify. In this build, I’m going to use a 6” BBR (“batch box rocket”) refractory core (insulating fire brick and ceramic fiber board) oriented from left to right, with the firebox door being part of the right hand wall of the firebox. Port (narrow exhaust slit) will be in the ceiling of the firebox on the far right, with a double shoebox riser (a secondary rectangular box above the firebox that’s highly insulated where secondary air, turbulence, reflected heat from the refractory insulation and mixing can create complete 2200 degree combustion without a catalytic combustor) directly above the firebox.

    A 24”x24”x14” deep square metal box will sit directly over the wood stove with double shoe box firebox and riser, and that will sit between 2 masonry benches on my family room fireplace hearth.

    For anyone familiar with rocket heaters, I just wanted to show how easy and cheap it can be to use old plate steel wood stoves like the Frontiersman to solve the common issue of how to “build and mount” a firebox door with glass window.

    I’m using one of my 6” shippable cores (with minor modifications) to build this firebox and double shoebox riser configuration, and I’ll add pictures as that takes shape. The primary air holes already in the firebox door will be modified for primary air. The holes under the door in the wood stove frame will be modified and used to introduce the secondary air through the recess in the 1” ceramic fiber board under the firebrick split floor of the firebox. (The two current air holes currently seen in the rear wall of the wood stove will be sealed off by the left side wall of the firebox.)
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    Last edited: Feb 10, 2018
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  2. BrianK

    BrianK

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    The firebox, along with the Double Shoebox Riser (DSR) on top, and the secondary air tube and flange mounted to the floor of the firebox. The holes in the wood stove frame under the door were widened to provide increased secondary air area.

    FF47441A-3684-4FF3-9C5F-57891AFBED42.jpeg 02FF6C2D-F05A-4A6F-AF67-7DF4F5E7400A.jpeg 137578E5-31A0-4C15-9A40-2437B872C7CF.jpeg A1FC34A9-E675-4DCE-B90E-21F1E84DD433.jpeg C8BDA286-3DAE-4510-A18B-3B0F6250E3A9.jpeg D81AD599-BE5A-48AE-AB47-758AD591B1CA.jpeg 6BEACD4A-3C57-4D34-952C-6F1C212D9B41.jpeg D23874B3-492B-4253-95B6-84D8032420F2.jpeg
     
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  3. BrianK

    BrianK

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    Test fit, temporary while I make measurements for the masonry benches. Hearth is 96” wide, and now 27” deep since I extended it. The wood stove is 24” wide, 17” tall. The square metal box on top of it is 24”x24”x14” tall. Benches will be blind ended and 24”x24”, with 2’ bench to the right of the rocket and 4’ to the left. The metal box on top will have a 4”x6” mica glass viewport into the DSR above the firebox. I’ll use the Conservo Toledo stove top cooker as an integrated white oven in the left hand bench. I’ll have around 2000 lbs of mass in the masonry benches. 65BFD6F7-7AD1-4D13-81CC-0945B557A793.jpeg CF20AA7B-96B3-4E3D-9162-E86FB25AB89C.jpeg
     
  4. Chaz

    Chaz

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    :popcorn::coldone:

    Hope the show hasn't ended.. I just grabbed a seat.
    I wish I could say that I followed all of what you said, but I can't, so I won't.o_O

    I'm sure I'll pick up a bit better understanding of things as the story progresses.

    Chaz
     
  5. Eric VW

    Eric VW Moderator

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    Peruse just about any of BrianK ’s threads on the subject... he’s accrued some serious knowledge and experience :yes:
    And he’s learned from the best in the movement...
    https://firewoodhoardersclub.com/forums/search/31951003/
     
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  6. Nico

    Nico

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    Great work Brian! Are you able to show us the final setup? I am curious how you did the final chimney plumbing.
     
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  7. SKEETER McCLUSKEY

    SKEETER McCLUSKEY

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    just buy a Blaze King
     
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  8. BrianK

    BrianK

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    Unfortunately we sold the old homestead and I sold off all the rocket mass heater stuff three years ago. I do know the fellow who bought this particular rocket stove was one of the “leaders” in the rocket mass heaters movement (he goes by “Uncle Mud” in that community) and he plumbed it into a mass masonry bench and successfully used it several years.

    I moved on from the rocket heater movement due to personal and chronic health reasons. Frankly I’ve forgotten most of it, but when I looked back into the “state of the art” of that movement recently, they had made disappointingly few breakthroughs.

    This was one of my other builds:
    Recent masonry rocket heater build and 55 gallon rocket heater
     
  9. BrianK

    BrianK

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    There’s something to be said for that.
     
  10. Canadian border VT

    Canadian border VT

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    Waiting on the teacher to impart more wisdom :popcorn:
     
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