Shippable core kits will be available January 1, 2018!

The 6” batch box shippable core kit will consist of 2/3 of the height of the left and right firebox wall, 9”, to be made from continuous 21”x9”x2 1/2” bricks of high density 2600•F insulating firebrick. It’s about 4 times stronger than regular 2300•F insulating firebrick and should withstand the loading of firewood in the firebox well. It will use regular insulating firebrick for the next 4 1/2” of the firebox walls. The rear wall will be 9” of the dense and 4 1/2” of the regular insulating fire brick. It will then use ceramic fiber board insulation for the roof. The port can be placed in a rear port, left or right sidewinder, or top (roof) port configuration.

You only lose about 1/3 the insulating value of regular insulating firebrick but this denser insulating firebrick has 4x the strength and seems strong enough for the left and right hand and rear walls and the port.

It will use regular dense non insulating firebrick for the floor though, as that gets the most abrasion and abuse from loading firewood. It seems a decent compromise to decrease mass and maintain insulating value for the firebox build . The upper walls and the roof maintain the highest insulation values for the rising heat inside the firebox.

The floor can either be flat dense regular firebrick splits, which is the best configuration for burning the flat bottomed compressed sawdust fire brick fuel I’m using, or the traditional PVDB “V” shaped configuration. The firebox will be 9” wide, 13 1/2” tall, and 18 1/2” deep (to accommodate 4 flat firebrick splits, a sill and a 1/2” gap to the firebox door.) The kit will NOT include the heavy firebrick for lining the floor. That can be sourced locally by the purchaser.

Roof can either be 1” or 2” ceramic fiber board. For a top vent, 1” might suffice, because the expansion chamber / horizontal riser will be built directly over the firebox roof. With a left or right sidewinder configuration the roof will extend over both the firebox and the expansion chamber/ horizontal riser which will be the same height as the firebox along the left or right side. The kit will include the expansion chamber / horizontal riser for all the configurations.

Secondary air will still be delivered via a recess in the ceramic fiber board under the firebrick floor. I’ve sourced marine grade 316 stainless steel tubing and mounts to make it easily attachable to a piece of metal plate between the ceramic fiber board under the floor and the layer of firebrick for the floor.

The expansion chamber/horizontal riser needs to maintain the highest temps so will be made of ceramic fiber board. It will be included unless the purchaser requests just the firebox.

Vertical 6” square risers can easily be constructed from 24”x9”x3” regular insulating firebrick arranged in a pinwheel fashion. Four bricks will create a 24” vertical riser, six will create a 36” riser, and 8 will create a 48” vertical riser. These bricks will be available separately

All of this kit will be robustly packaged to protect the fragile insulating firebrick and shipped in one box via UPS or USPS. (The ceramic fiber board for the floor and ceiling of left and right sidewinder configurations may have to be shipped in a separate box.)  Assembly will be simple with easy to follow directions.

Photos this week hopefully.

I’m still contemplating having a vacuum formed ceramic fiber shape made that would take the place of the 4 1/2” regular insulating firebrick wall extension and ceramic fiber board roof and serve as a cap for the HD 2600 9” walls. It would further simplify creation of the firebox but cost a lot of money up front for molding fees. I’m also contemplating having one vacuum molded ceramic fiber shape for the expansion chamber / riser.

At present the shippable core kit will not include these vacuum formed ceramic fiber shapes.

Shippable core kits will be available the first week of 2018.

My website is not up and runnng yet, but will be www.pennrocketheaters.com and the eBay store will be Penn Rocket Heaters.

I’ll have a price within a week. I still have to sit down with all the invoices and figure out the math. (Designing and building and experimenting was the easy/fun part! I’m not procrastinating, I’m just not a numbers person.)

Each of these cases on the bottom row contains five 24”x9”x2 1/2” or four 24”x9”x3” insulating firebricks:

8” batch box shippable core kits should be available by February.

Here’s a core going together with the barrel stove firebox door I’ll be utilizing for these when using the upright 55 gallon drum configuration. The floor and secondary air tube havn’t been assembled yet  

Pre port secondary air tubes will be 1.67” diameter marine grade 316 stainless. The tube can easily be removed from the stainless steel flange base and replaced if/when it eventually burns out. Steel tube thickness is 2mm/ 14 Gauge. (It’s simply marine grade handrail tubing and hardware.)

I like the idea of your core kits. I'd like to see what you're offering on a simple but effectively laid out website however. You should try and get that done first or will you will have a hard time getting around to it later and your "business efficiency" will suffer as a result. You will end up spending way too much time fielding and explaining your "products" without it.

barney fife wrote:I like the idea of your core kits. I'd like to see what you're offering on a simple but effectively laid out website however. You should try and get that done first or will you will have a hard time getting around to it later and your "business efficiency" will suffer as a result. You will end up spending way too much time fielding and explaining your "products" without it.

Thanks Barney. I’ll have the full website online January 1, 2018. We’re working on it now and the www.pennrocketheaters.com domain is already registered.

Here’s a barrel rocket stove I’m currently building using Peters new shoebox configuration and my shippable core. I’m thrilled with the 2600• HS (high strength) insulating firebricks. They’re more dense and resistant to abrasion than I had dared hope. I cut one for the firebox floor to fit around the secondary air tube flange. (I have to cut them very slowly so I don’t stall my floor model band saw and they’re much harder on the blades.)

There’s a small mica glass view port in the front of this expansion chamber/riser and there will be a corresponding mica glass view port in the front of the barrel to view the fire coming through the top port. This is just an experiment to verify it’s burning properly in a rams horn fashion.

The entire 6” rocket batch box heater will fit completely in one upright 55 gallon drum. The bottom third of a second drum sits underneath the main barrel and serves as both a pedestal and a manifold for the barrel rocket above it. (When I cut out the barrel lid, which forms the floor under the batch box, I also cut tabs in the metal and bent them down so that 4 bolts hold the lid of the main drum to the pedestal / manifold supporting it. You can see two of the bent tabs with nuts on the left and right of this photo.)

Brian James wrote:Here’s a barrel rocket stove I’m currently building using Peters new shoebox configuration and my shippable core.

Brian, there's something you need to know about that port as a venturi. Somehow, the width dimension of the port should be close to the depth of it. I tried the DSR with a stainless plate between the firebox and expansion chamber and it burned quite dirty that way, I couldn't persuade it to behave itself. So I'd suspect the ceramic fibre board should be quite a lot thicker there.

Also, the floor channel should end about halfway in the port, not just before. The different configurations aren't fully understood yet but this is what I found out while testing it so far.

Peter van den Berg wrote:
Brian, there's something you need to know about that port as a venturi. Somehow, the width dimension of the port should be close to the depth of it. I tried the DSR with a stainless plate between the firebox and expansion chamber and it burned quite dirty that way, I couldn't persuade it to behave itself. So I'd suspect the ceramic fibre board should be quite a lot thicker there.

Also, the floor channel should end about halfway in the port, not just before. The different configurations aren't fully understood yet but this is what I found out while testing it so far.

Thank you Peter. I had been thinking about adding another inch of ceramic fiber board to the roof of the firebox, so I’ll go ahead and do that, then add a half inch directly around the port.

As far as the secondary air, if I understand correctly, you are suggesting moving the flange and tube forward towards the firebox door so it’s halfway between the rear and front ends of the port? As far as height goes, it’s currently a half inch below the port. Is that adequate or should it be shorter?

I truly appreciate the feedback because I’m not going to have the time to experiment with this one that I would have preferred. I do realize it is still an experimental configuration and all the parameters aren’t firmly established yet, but it has huge potential for fitting an entire 6” system within one 55 gallon drum.

Brian James wrote:As far as the secondary air, if I understand correctly, you are suggesting moving the flange and tube forward towards the firebox door so it’s halfway between the rear and front ends of the port? As far as height goes, it’s currently a half inch below the port. Is that adequate or should it be shorter?

The tube should be dead against the back wall and as such is at the back of the port. The thickness of the firebox ceiling is in your proposal 2.5", as is the port depth. I'd recommend the stainless tube to end about halfway in the depth of the port, it's now 0.5" below. So it should be just 1.5" higher than it is at the moment.

I tried several configurations but this one seems to yield the best results and is the simplest at the same time. What's the diameter of that SS duct? It looks a bit small compared to what I used at home and in Montana.

Peter van den Berg wrote:The tube should be dead against the back wall and as such is at the back of the port. The thickness of the firebox ceiling is in your proposal 2.5", as is the port depth. I'd recommend the stainless tube to end about halfway in the depth of the port, it's now 0.5" below. So it should be just 1.5" higher than it is at the moment.

I tried several configurations but this one seems to yield the best results and is the simplest at the same time. What's the diameter of that SS duct? It looks a bit small compared to what I used at home and in Montana.

Great, thanks again Peter! I have enough adjust-ability the way I made it to do both of those fairly easily.

The secondary air passage under the firebrick is 2"x1" and the SS secondary air delivery tube is 1.67" diameter. Since you had been using 1 1/4" square tube I felt that should be adequate?

I don't know where you saw the square tube, I used several rectangle ducts at home, the best results were obtained with 60x40x2mm (2.36" x 1.57" x 0.08") and 2.25" x 1.5" in Montana. I'm not that sure about the latter one, maybe it happened to be slightly larger. The tubing I've been using was roughly 1.7 times larger compared to yours. The double shoebox air inlet openings are nearly 1:1, primary and secondary. It's quite different from the straight batch box or the sidewinder.

Peter van den Berg wrote:I don't know where you saw the square tube, I used several rectangle ducts at home, the best results were obtained with 60x40x2mm (2.36" x 1.57" x 0.08") and 2.25" x 1.5" in Montana. I'm not that sure about the latter one, maybe it happened to be slightly larger. The tubing I've been using was roughly 1.7 times larger compared to yours. The double shoebox air inlet openings are nearly 1:1, primary and secondary. It's quite different from the straight batch box or the sidewinder.

I must have been thinking of your earlier standard secondary air supply tube?

Regardless, I have a 3” SS exhaust pipe that Matt Walker had recommended recently. I can easily convert to that if this size is insufficient. What would be signs of starving for secondary air?

I ended up using the larger SS auto exhaust tube that Matt Walker had recommended. It’s about 2 1/8” diameter. (It’s hard to tell here but it is up against the rear wall of the port.) I also made the port depth 2 1/2”.

Brian James wrote:What would be signs of starving for secondary air?

The little window in the top box would get black and stays that way. And the whole setup would emit smoke I guess.
That 2-1/8" diameter is quite close, should be good.

I'll admit, I've been stalking this thread as a guest to the permies forum up until about a week ago, when I got my account. Did you ever decide on a price for these kits?

Logan Keister wrote:I'll admit, I've been stalking this thread as a guest to the permies forum up until about a week ago, when I got my account. Did you ever decide on a price for these kits?

Hi Logan,
I'll be honest, between the 8 days I spent in NC with the rocket heater builds there and other travel this month, I've just gotten around to a detailed cost analysis in the last couple days. Because of the price of these big blocks, and using the more expensive 2600degree HS (High strength) insulating fire brick ("IFB") plus the high cost of ceramic fiber insulation board, plus my time to pick them up at the factory two hours away and to hand make each of these, the introductory price for a 6" batch box left or right sidewinder port or rear port design, with a simple ceramic board box expansion chamber/riser that will work with any of these configurations, will be $349 plus shipping. (This ceramic board expansion chamber/ riser can either be used horizontally or vertically, is about 8" deep and the length and width of the fire box.)

The kit will be easily assembled by the purchaser. The side bricks will be assembled and attached to the floor with 3000degree refractory mortar (supplied) and the roof of the firebox as well as the expansion chamber/riser walls and roof will be assembled with ceramic cement (also supplied.)

I still have to package a shippable core kit and take it to UPS to get a weight and typical shipping prices.

An 8" shippable core will be available February 1, 2017. It will cost more in proportion to the much larger firebox.

A 6" double shoe box configuration will be available in the coming months as the results come in on the design. That configuration is still experimental.

I'l also make whole individual 2300degree IFB 24"x9"x2.5" or 3" (for traditional vertical risers) and 2600HS 24"x9"x2.5" IFB slabs, as well as individual sheets of different thicknesses of ceramic fiber board available, as well as the stainless steel secondary air flanges and tubes, in the near future.

(I'm still working on the website with my web designer and we still hope to have a basic website and eBay store online January1, 2018, but that depends on his availability over these holidays, so it could be delayed a week or two.)

Merry Christmas and Happy New Years!
Brian

The shippable core will be similar to the fire box below, with 2600HS IFB sides and 1" ceramic fiber board roof, a 1" ceramic fiber board floor with a secondary air recess between two sheet metal plates, but with a short stainless steel secondary air delivery tube like in the second photo. The purchaser will need to line the firebox floor, either with flat dense firebrick splits, or with angled dense fire bricks like in PvdB's illustrations:

Brian James wrote:

Logan Keister wrote:I'll admit, I've been stalking this thread as a guest to the permies forum up until about a week ago, when I got my account. Did you ever decide on a price for these kits?

Hi Logan,
I'll be honest, between the 8 days I spent in NC with the rocket heater builds there and other yravel this month, I've just gotten around to a detailed cost analysis in the last couple days. Because of the price of these big blocks, and using the more expensive 2600degree HS (High strength) insulating fire brick ("IFB") plus the high cost of ceramic fiber insulation board insulation, plus my time to hand make each of these, the introductory price for a 6' batch box left or right sidewinder port or rear port design, with a simple ceramic board box expansion chamber/riser that will word with any of these configurations, will be $349 plus shipping. I still have to package a shippable core kit and take it to UPS to get a weight and typical shipping prices.

An 8" shippable core will be available February 1, 2017. It will be more in proportion to the much larger firebox.

A 6" double shoe box configuration will be available in the coming months as the results come in on the design. That configuration is still experimental.

I'l also make whole individual IFB 24"x9"x2.5" or 3" slabs and individual sheets of different thickness of ceramic fiber board available, as well as the stainless steel secondary air flanges and tubes, in the near future.

(I'm still working on the website with my web designer and we still hope to have a basic website and eBay store online January1, 2018, but that depends on his availability over these holidays, so it could be delayed a week or two.)

Merry Christmas and Happy New Years!
Brian

The shippable core will be similar to the fire box below, with 2600HS sides and 1" ceramic fiber board roof, a 1" ceramic fiber board floor with a secondary air recess between two sheet metal plates, but with a short stainless steel secondary air delivery tube like in the second photo. The purchaser will need to line the firebox floor, either with flat dense firebrick splits, or with angled fire bricks like in PvdB's illustrations:

All things considered, if the shipping were to land somewhere in the $100 - $150 range, $500 +/- total is something I could certainly live with. I like the idea of starting to mess with RMH's in my spare time, but my current situation is as such that I may be better just buying the core and starting there rather than trying to learn from scratch. I bought the book from Ernie and Erica W. not all that long ago, but haven't had time yet to read it. Still trying to navigate my way through my day job, school, and being a newlywed, all the while living in an old farmhouse (that conveniently had frozen water lines to the kitchen sink yesterday). Can't wait to see the site when it's done, I have it pinned as a favorite! Merry Christmas and Happy New Years to you as well!

Logan Keister wrote:
All things considered, if the shipping were to land somewhere in the $100 - $150 range, $500 +/- total is something I could certainly live with. I like the idea of starting to mess with RMH's in my spare time, but my current situation is as such that I may be better just buying the core and starting there rather than trying to learn from scratch. I bought the book from Ernie and Erica W. not all that long ago, but haven't had time yet to read it. Still trying to navigate my way through my day job, school, and being a newlywed, all the while living in an old farmhouse (that conveniently had frozen water lines to the kitchen sink yesterday). Can't wait to see the site when it's done, I have it pinned as a favorite! Merry Christmas and Happy New Years to you as well!

Actually, I'm pretty happy with where this shippable core kit ended up as far as a reasonable price. If I had pursued a vacuum formed ceramic fiber shape lined with dense fire brick splits as a core it would have cost $500 to $600 a piece, and I really thought that would have been too much. I can still go that route as another option in the future if there's demand for it.

I've been fortunate in that this new design didn't require tooling/molding costs up front. Therefore a Kickstarter campaign wasn't necessary to make these available!

The listing for these 6" shippable cores is available now at https://www.ebay.com/itm/6-batch-box-rocket-heater-shippable-core-/122891620740?hash=item1c9ce95184

This is wonderful, so glad someone is doing this.  And that you've gotten to the actual sales stage!  Congrats!

Can you give a real quick (like, three or four sentences maybe) intro to the level of work required to turn one of your kits into an actual functional heater (mass or not)?  I'm trying to gauge the feasibility.  Does one have to have studied the books, know some special skills, have nine strong friends, etc. etc. etc.

Also, how much does the kit weigh....would one able-bodied person be able to wrangle it inside from delivery by themselves?  

Thanks!

Instructions:

The kit is between 60 and 70lbs, and comes in one 24"x16"x16" heavy duty cardboard box. If its too heavy to manage, you can just open it up where UPS left it and carry the pieces individually. The heaviest pieces are the two 21"x9" pieces of 2600HS IFB, but they're only about 12lbs a piece. Handle everything with care as both IFB and ceramic fiber board are relatively easy to break.

If you signified which rocket configuration you desired at time of purchase, left or right sidewinder or rear port, the Venturi port will already be cut in the firebox walls. If not, pre-set the parts of the firebox walls, figure out where you'll be placing the port, then follow Peter van den Berg's instructions for a 6" rocket heater at http://batchrocket.eu/en/building#dimension to cut the port in the IFB firebox walls. IFB can be drilled easily for pilot holes for the port and cut easily with a hacksaw blade, other hand saw, band saw or jig saw.

The parts go together pretty easily like a sheet cake on the bottom. First, one piece of 21" long sheet metal with a 1" lip at the sides and 3" at the rear. Next, 1" ceramic fiber board with the cut out up the middle for a secondary air channel is set flat inside the sheet metal, using the lips as a guide. Then assemble the stainless steel flange to the second, 20.5" piece of sheet metal using the mounting holes provided. Place this metal sheet directly on top of the 1" ceramic fiber board, with 1/2" space to the front edge of the 1" ceramic fiber board. This metal sheet has upward facing 1" lips on the sides, no rear lip, and an upward facing 3 1/4" lip as a sill in the front. Assemble the round stainless steel tube flush in the flange, and tighten the 2.5mm Allan wrench set screw.

Next walls are assembled. Using 3000 degree refractory mortar (supplied) put a thin coat on the bottom edge and left and right edges of the 13.5"x9" IFB rear wall, and place it firmly with a 9" side facing down, centered against the rear lip of the sheet metal, with a 2.5" space on the left and the right side for the side walls.

Left and right walls are next. Put mortar on the bottom of the 21"x9" pieces of IFB and firmly set them in place on the left and right sides, using the left, right and rear lips of the sheet metal as a guide. Now do the same with the two 21"x4.5" pieces of IFB,making sure they contact the rear walls. GENTLY tap all the walls together and downward (a rubber matter helps) to seat them firmly in place.

If you signified which configuration, left or right sidewinder or rear port as well as horizontal or vertical riser orientation (only with sidewinders), the 6" exhaust hole will already be cut in the ceramic fiber board for the expansion chamber/riser. If not, set up the expansion chamber/riser first, figure out where you want to place your 6" exhaust hole, make a pilot hole with a drill bit, and cut it out with a hack saw (blade only), drywall saw or jig saw.

Next take the ceramic cement (supplied) and apply to the top edges of the left, right, and rear firebox walls. Place the 20.5"x14" piece of 2" which ceramic board firmly on top of the firewalls. Place some weight centered over the rear, left and right walls of the firebox (a line of firebrick or two stacked red bricks should be sufficient) and let it all set up for at least 12 hours. Next set the four 2" expansion chamber walls upright in a 14"x16.5" rectangle. Apply the ceramic cement to the opposing surfaces of the walls and press firmly together, then apply ceramic cement to the top of the 4 walls and firmly press the 14"x16'.5" piece if 1" ceramic fiber board on top of the ceramic fiber rectangle walls. Place some weight (a line of firebrick or two stacked red bricks should be sufficient) centered over the 4 walls and let it set up for at least 12 hours.

After the firebox and the expansion chamber/riser have been allowed to set, place the expansion chamber in the left or right sidewinder horizontal or vertical orientation, or vertical orientation for the rear port configuration. Apply ceramic cement to the surfaces which will contact the firebox, then press them together firmly, using weight to hold them in position while they set for another 12 hours. Be very careful in removing the weights before building the remainder of the rocket heater so as not to cause them to separate.

Ceramic cement will be supplied in a ziplock bag approximately the consistency of runny peanut butter or thick pancake batter, and will be applied with a cake icing bag and nozzle (supplied.)

Refractory mortar will also be supplied in a ziplock bag and can be applied with a small trowel (or a big kitchen spatula, as long as your spouse never finds out ;-)

(I just typed up instructions from the top of my head, and don't have photos to illustrate them yet, so please let me know if they're not clear.)

C Jones wrote:This is wonderful, so glad someone is doing this.  And that you've gotten to the actual sales stage!  Congrats!

Can you give a real quick (like, three or four sentences maybe) intro to the level of work required to turn one of your kits into an actual functional heater (mass or not)?  I'm trying to gauge the feasibility.  Does one have to have studied the books, know some special skills, have nine strong friends, etc. etc. etc.

Also, how much does the kit weigh....would one able-bodied person be able to wrangle it inside from delivery by themselves?  

Thanks!

This kit is just the firebox core and expansion chamber/riser. There's no door, barrel or masonry tower, exhaust manifold, bench or bell, flue, etc. Its still going to take a decent knowledge base of rocket heater basics to turn take this core and then build the rest of a functioning batch box riser rocket heater around it. But this core contains the hardest to source refractory parts for the firebox core and riser, in easy to assemble large pieces (eliminates most of the masonry joint work) , so it should make the rest of the build relatively easy.

Total weight is 60-70 pounds.

Folks have informed me they'd like to pick up a shippable core in person and save the shipping and handling costs, so I've created a second post for "Local pickup only." (I'm located in Hollidaysburg PA):
https://www.ebay.com/sch/pennrocketheaters/m.html?_nkw=&_armrs=1&_ipg=&_from=

This is great stuff.  I'm not quite ready to buy yet, but will definitely keep this in mind.  Keep us posted regarding when your web site is completed.  

My apologies, folks. I just took down the eBay ads for my shippable cores because my hands are going to be full for the coming months. (I’m the primary care taker for my 82 yo mom, and she just had massive emergency cardiac surgery, so I expect to be preoccupied for the foreseeable future.)

If you’re still interested in obtaining one of the 6” BBR shippable cores and not in a hurry, get in touch with me here via private message and I’ll still make them available that way. I just can’t fulfill any eBay orders in a timely manner for the foreseeable future.

Brian James wrote:Folks have informed me they'd like to pick up a shippable core in person and save the shipping and handling costs, so I've created a second post for "Local pickup only." (I'm located in Hollidaysburg PA):
https://www.ebay.com/sch/pennrocketheaters/m.html?_nkw=&_armrs=1&_ipg=&_from=

Are these no longer being made?