The folks who report the “exploding” bricks or blocks or rocks have used wet materials which will burst from steam building up inside the stone, brick, what have you. Use dry materials folks . 🙂
I've used cement blocks. You're letting it have too much air. I put some cardboard over the air intakes and it burned great. So great it warped my stainless steel grill plate. I also put some wood vertical in the chimney to get it started.
Your cinderblock one didn't do well because your chimney needed to be one block higher, or you could put a makeshift metal chimney on it. Simple fix, and I BET you have something to make the chimney a bit taller, just sitting around on-hand, right? I'm so glad you're doing these rocket stove trials, they're a favorite of mine!
They need air cans (squished tomatoes can or similar that you put the sticks on to of at the entrance hole) but the brick one is too small for a corn can -- use a tomato paste can. Squish it more on one end than the other and put the more squished end in first. Then put the wood on top. Won't smoke as much.
A bit of chicken wire or hardware cloth works well too. Loosely roll up the wire and push it down into a rectangular shape that fills up the bottom third of the feed tube. The air going in under the sticks is what makes a rocket stove so efficient, the sound it makes with the air rushing through it is where the rocket name comes from.
I used clay brick as a wall for the coal in my side blast forge. They definitely crumbled and actually melted! But they never blew up. To be honest, if I was using them to actually contain the heat of the forge and not just serve as a boundary I am not sure I would have been as lucky. But my bricks were quite old. I do believe that some caution should be taken, but for use with normal fire temperatures I don't think there is a problem. Forges, on the other hand, are much much hotter.
I know fieldstone will explode if it has too much water in it from the water heating so maybe people were thinking of that. With as porous as brick and concrete block can be, I can't imagine the water creating enough pressure to explode.
You are correct about the cement blocks and cement bricks not exploding in the stoves. The ones that explode and very very rarely were the cinder blocks they use to make a long time ago. I’ve never seen it happen but as a mason I heard it happened a few times back in the 50s. Concrete blocks are much stronger and of better material. Now if you used fired clay bricks they wouldn’t crack on you so much. They are fired in kilns up to 2000 degrees and your stove won’t get anywhere near that.
I went to a brick and stone building supply company in my own hometown in early 2021. I bought 4 cinder blocks and asked that 1 of them be cut with the H block cut right there. They did it for me. I looked at fire brick prices but even 18 fire bricks were more than 4 times the price of 4 cinder blocks.
Blocks no, cause we don't all have tools. Won't work for most of us. I'm an elderly lady trying to find a way to have heat, to cook, boil water, if needed. The 3 brick is cheaper but, I don't have tools, hoping the brick one will work. Then I got to find a way to cook or heat it. No wood. I'll find your revised brick. I've seen people building cans and that just doesn't look safe. I'm really worried about our power going out. Thank you for showing us. Miss brick lol, works for me vicki
The ones I've seen made out of block actually put the base block with the flat side up with a half block on the back half of it. They still use the vertical feed block like you did but they also put a vertical block on either side of the main combustion chamber to close it in and then two or three blocks oriented like your to form the "chimney". The better ones I've seen are three blocks wide up to the third tier (the first chimney level) with two more blocks for the chimney on top of that. You wind up with two work surfaces on either side when you do it that way.
I built a 7 cinder block rocket stove for me and my daughter. I use mine randomly. She uses hers all the time. Her cinder blocks cracked but did not change the cooking much. I modified mine by adding: 1. A hoe made out of 3/8" rebar and 14 ga flat steel end to make the hoe to clean and stoke the fire. 2. I put a piece of c-purlin 17" long with a cutout of 5x3 1/2....1/2 inches from end to make a hole in the c-purlin. I then welded a piece of diamond mesh over the cutout. This was to direct the air flow under the fire. Works great. Increased fire flame and heat immensely. 3. I have discovered that if you block all the air coming into the flame area except the c-purlin intake, then the flame is even higher and hotter. This is my next project. I am either going to use wood frame with rockwool to protect the wood to block the air or a single piece of 14 ga metal and keep it in place using magnets apoxied to the cinder blocks. Yes magnets ruin if heated BUT the location of the magnets the blocks do not get hot but rather only get warm to the touch. 4. Next I am going to build an adjustable pot holder so that you can raise or lower the pot to help control heat immediately.
Needs air flow under the fuel. An empty can with the end lids cut open can be laid on the bottom and sticks inserted on top of it. Might need to squish the can down a bit.
Both stoves need a chimney or "riser" and they won't smoke...... the chimney needs to go up another 12 to 18 inches and you will see a whole new "stove." Clay bricks (or shale) are fired to 1800 degrees in their manufacture. The brick is better than concrete. Yes.. over time it will crack from rapid cold to hot to cold, back and forth. Warm up brick stoves slowly and bring them back down to cold slowly and there will be no problem for a very long time. One of the main reasons for firebricks / refractory bricks over red bricks is not the high temperature in a wood stove, as much as they have no problem going ice cold to very hot in just a few minutes.... no cracking.
You must seal all the joints, mud or clay works. Also, the taller the top (up to a point anyway) the more rockety it becomes. I think it is a 1:4 ration - 4 times higher than the input length.
Dry concrete block makes a good stove for short term emergencies. If you wqnt it to last then red brick or fire brick is the way to go. You can buy U shaped lintel blocks and half blocks that you dont have to cut.
Build the fire brick design with another layer or two where the bottom layer is an air passage to allow air to go up the chimney. Maybe keep the air passage open at both ends to allow for easy clean out of ashes that collect there. Or, just use a can like everyone says.
You know... I've been looking around and don't see anyone doing a video about how to put a chimney set up on these cinder block or brick rocket stoves. The idea is you'd need a chimney if you did it in a hot tent. So ... what are you supposed to do adapt the cinder block or brick rocket stove to a winter hot tent?
Appears to me that the cinder block one is starved for oxygen hence smoke the brick one with all the airggaps with the brick not being mortared together and having rougher surface than the smooth factory made cinder block which would not allow air creepage Plus in this test having the test at the mouth of garage wouldn't there be some sort of draft blowing inwards hence taking oxygen I.e. the draft away from the rocketstoves? It seems to me it doesnt matter which one you use but you would want your stove to be steady so your pot or skillet doesnt end up on the ground and that you dont really want air coming from the cracks in the whole structure. But from where you load it( really I don't know but it would be steadier if the bricks were motared in and it could be controlled more if the oxygen were coming in from one place, no? Also the elephant in the garage to me is the brick one... The one going across the mouth of the borehole is just dangling and could fall in while using it which would suck Things crack cause they heat or cool too fast which could be slowed with. Insulating the outside. - fiberblanket or refractory material(vermiculitr Portland mix of some kind Im typing/thinking out loud
I can tell you it does one fall I was burning and did not know there was old brick when I heard explosion I was about 20' away and a chip from the brick and it flew down my hoodie and I got burned. It does explode
My 2 cents...I don’t see how and have never heard of concrete block exploding before TH-cam. But I did experience small explosions while burning stains off of my concrete driveway with a propane weed torch that I let linger too long in one place. YMMV
Or hit the concrete block towards the outside instead of crushing it slamming into it haha just lay it down.. hit that slot you had to cut from the middle out not in much easier 👍👍you might have to flip it to knock another chunk out but its a few swings with a regular hammer 🔨
You need a draft, better off using the masonry brick you broke in half. Can create the draft needed for air, put it in middle. With other mason brick on top. Weight holds it together. Watched others use this way. USe what you got!
Your stoves suck - I've worked masonry for over 35 years. You had one block (8.8.16) with a slot in it. That slot is for opening the end. With a masonry trowel (or chisel) you can cut the thin center out then cut along the edges to remove the two pieces on the end. With a little time and heat the blocks will crumble. With bricks you need to use fire brick.
More Rocket Stove Vids: th-cam.com/play/PLK9GxIRaLC5Vc0PrAustRJgO2hDJiAfpa.html
The folks who report the “exploding” bricks or blocks or rocks have used wet materials which will burst from steam building up inside the stone, brick, what have you.
Use dry materials folks . 🙂
I made one with six cinder blocks without having to cut any blocks. I added to concrete pavers. Like you said, use what you got. Thanks for sharing!
I've used cement blocks. You're letting it have too much air. I put some cardboard over the air intakes and it burned great. So great it warped my stainless steel grill plate. I also put some wood vertical in the chimney to get it started.
Your cinderblock one didn't do well because your chimney needed to be one block higher, or you could put a makeshift metal chimney on it. Simple fix, and I BET you have something to make the chimney a bit taller, just sitting around on-hand, right? I'm so glad you're doing these rocket stove trials, they're a favorite of mine!
Have to look around the garage... 😀
Great ! Just built my first one today, using junk bricks. Love the little guy. THANKS much'ly for this video !
Thanks for showing the concrete block destruction, I laughed out loud!
Grinder for the win!
They need air cans (squished tomatoes can or similar that you put the sticks on to of at the entrance hole) but the brick one is too small for a corn can -- use a tomato paste can. Squish it more on one end than the other and put the more squished end in first. Then put the wood on top. Won't smoke as much.
A bit of chicken wire or hardware cloth works well too. Loosely roll up the wire and push it down into a rectangular shape that fills up the bottom third of the feed tube. The air going in under the sticks is what makes a rocket stove so efficient, the sound it makes with the air rushing through it is where the rocket name comes from.
@@terryjohnson2093Yes, and one more vertical chiminey block to help draw more air will make it smoke even less.
Going to try brick design this weekend. I thought block would perform better.. I was wrong.
Thanks! 🔥
God bless
I used clay brick as a wall for the coal in my side blast forge. They definitely crumbled and actually melted! But they never blew up. To be honest, if I was using them to actually contain the heat of the forge and not just serve as a boundary I am not sure I would have been as lucky. But my bricks were quite old. I do believe that some caution should be taken, but for use with normal fire temperatures I don't think there is a problem. Forges, on the other hand, are much much hotter.
I know fieldstone will explode if it has too much water in it from the water heating so maybe people were thinking of that. With as porous as brick and concrete block can be, I can't imagine the water creating enough pressure to explode.
Yes Robert I’ve seen that too. I tire of people posting online without doing any research. 😉
You are correct about the cement blocks and cement bricks not exploding in the stoves. The ones that explode and very very rarely were the cinder blocks they use to make a long time ago. I’ve never seen it happen but as a mason I heard it happened a few times back in the 50s. Concrete blocks are much stronger and of better material. Now if you used fired clay bricks they wouldn’t crack on you so much. They are fired in kilns up to 2000 degrees and your stove won’t get anywhere near that.
Thanks for the note Tony, I get so many comments on this, people screaming at me ;) Eric.
The brick looks easier, for sure. I am going to see if I have enough of them to do this. I look forward to your modification video!
This weekend!
My mod to my brick stove is self cleaning
I went to a brick and stone building supply company in my own hometown in early 2021. I bought 4 cinder blocks and asked that 1 of them be cut with the H block cut right there. They did it for me. I looked at fire brick prices but even 18 fire bricks were more than 4 times the price of 4 cinder blocks.
Finally! Someone who calls them CONCRETE blocks. Most say cinder blocks, even when not made of cinders.
Blocks no, cause we don't all have tools. Won't work for most of us. I'm an elderly lady trying to find a way to have heat, to cook, boil water, if needed. The 3 brick is cheaper but, I don't have tools, hoping the brick one will work. Then I got to find a way to cook or heat it. No wood. I'll find your revised brick. I've seen people building cans and that just doesn't look safe. I'm really worried about our power going out. Thank you for showing us.
Miss brick lol, works for me vicki
Love it! How about an updated egg in a hole grilled cheese video on the brick rocket stove? Maybe when it stops raining 😀
Working on it...
The ones I've seen made out of block actually put the base block with the flat side up with a half block on the back half of it. They still use the vertical feed block like you did but they also put a vertical block on either side of the main combustion chamber to close it in and then two or three blocks oriented like your to form the "chimney". The better ones I've seen are three blocks wide up to the third tier (the first chimney level) with two more blocks for the chimney on top of that. You wind up with two work surfaces on either side when you do it that way.
Good info Brian, thx for that. Eric.
I got a bunch of bricks I could use. Looking forward to the next video with the improved version
Working on it Peter. Eric.
I built a 7 cinder block rocket stove for me and my daughter. I use mine randomly. She uses hers all the time. Her cinder blocks cracked but did not change the cooking much.
I modified mine by adding:
1. A hoe made out of 3/8" rebar and 14 ga flat steel end to make the hoe to clean and stoke the fire.
2. I put a piece of c-purlin 17" long with a cutout of 5x3 1/2....1/2 inches from end to make a hole in the c-purlin. I then welded a piece of diamond mesh over the cutout. This was to direct the air flow under the fire. Works great. Increased fire flame and heat immensely.
3. I have discovered that if you block all the air coming into the flame area except the c-purlin intake, then the flame is even higher and hotter. This is my next project. I am either going to use wood frame with rockwool to protect the wood to block the air or a single piece of 14 ga metal and keep it in place using magnets apoxied to the cinder blocks. Yes magnets ruin if heated BUT the location of the magnets the blocks do not get hot but rather only get warm to the touch.
4. Next I am going to build an adjustable pot holder so that you can raise or lower the pot to help control heat immediately.
Needs air flow under the fuel. An empty can with the end lids cut open can be laid on the bottom and sticks inserted on top of it. Might need to squish the can down a bit.
My neighbor had his chimney torn down. I salvaged about 200 bricks. (with permission) . I'm very pleased.
Excellent! Pizza time.
Both stoves need a chimney or "riser" and they won't smoke...... the chimney needs to go up another 12 to 18 inches and you will see a whole new "stove." Clay bricks (or shale) are fired to 1800 degrees in their manufacture. The brick is better than concrete. Yes.. over time it will crack from rapid cold to hot to cold, back and forth. Warm up brick stoves slowly and bring them back down to cold slowly and there will be no problem for a very long time. One of the main reasons for firebricks / refractory bricks over red bricks is not the high temperature in a wood stove, as much as they have no problem going ice cold to very hot in just a few minutes.... no cracking.
you can mix cement block and brick. Use a small block for the chimney, use the brick for the wood feed and air intake.
How many hours do you get out of the bricks before they crack from the heat exchange? (ball park)
You must seal all the joints, mud or clay works.
Also, the taller the top (up to a point anyway) the more rockety it becomes.
I think it is a 1:4 ration - 4 times higher than the input length.
How long do your salvaged brick and block pizza ovens last before cracking Impairs their function? How temporary are they in your experience?
Dry concrete block makes a good stove for short term emergencies.
If you wqnt it to last then red brick or fire brick is the way to go.
You can buy U shaped lintel blocks and half blocks that you dont have to cut.
Build the fire brick design with another layer or two where the bottom layer is an air passage to allow air to go up the chimney. Maybe keep the air passage open at both ends to allow for easy clean out of ashes that collect there. Or, just use a can like everyone says.
I like the brick stove the best your right bricks just crack been in lots of house fires
Exactly!
You know... I've been looking around and don't see anyone doing a video about how to put a chimney set up on these cinder block or brick rocket stoves. The idea is you'd need a chimney if you did it in a hot tent.
So ... what are you supposed to do adapt the cinder block or brick rocket stove to a winter hot tent?
Appears to me that the cinder block one is starved for oxygen hence smoke the brick one with all the airggaps with the brick not being mortared together and having rougher surface than the smooth factory made cinder block which would not allow air creepage
Plus in this test having the test at the mouth of garage wouldn't there be some sort of draft blowing inwards hence taking oxygen I.e. the draft away from the rocketstoves?
It seems to me it doesnt matter which one you use but you would want your stove to be steady so your pot or skillet doesnt end up on the ground and that you dont really want air coming from the cracks in the whole structure. But from where you load it( really I don't know but it would be steadier if the bricks were motared in and it could be controlled more if the oxygen were coming in from one place, no?
Also the elephant in the garage to me is the brick one... The one going across the mouth of the borehole is just dangling and could fall in while using it which would suck
Things crack cause they heat or cool too fast which could be slowed with. Insulating the outside. - fiberblanket or refractory material(vermiculitr Portland mix of some kind
Im typing/thinking out loud
Excellent ideas here Patrick, thx for typing while you think. Eric.
Are the cinder blocks regular fit in the blocks or heat treated fire Brick ?
You have more confidence in that table than I do lol
It works pretty good! Eric.
Cement block or cinder blocks??
Fantastic as always Eric!
Thx!
I can tell you it does one fall I was burning and did not know there was old brick when I heard explosion I was about 20' away and a chip from the brick and it flew down my hoodie and I got burned. It does explode
Keep the flame in block with damper board on feeding side more vacume
It is really great..👍👍
thx!
My 2 cents...I don’t see how and have never heard of concrete block exploding before TH-cam.
But I did experience small explosions while burning stains off of my concrete driveway with a propane weed torch that I let linger too long in one place.
YMMV
Or hit the concrete block towards the outside instead of crushing it slamming into it haha just lay it down.. hit that slot you had to cut from the middle out not in much easier 👍👍you might have to flip it to knock another chunk out but its a few swings with a regular hammer 🔨
Wouldn't the table where you put the bricks burn with the heat?
Probably over time, yes, this was just for the video :)
Muito bom Parabéns nota 1000
For the h block use 2 pavers and a brick to make the H.
Thank you so much!!!
bricks only pop if they are wet as steam build up in them and then they only go pop not bang most times bits fall off them
yes, i've seen similar, Thx!
put a crushed can in the block oven for better air flow.
Both would burn better if you can elevate the wood with a grate so air can come in under the wood and fire
The tighter the cracks where it goes together the better.
Thanks Bro
mind blown - in the first sentence... how do you know i am into rocket-stoves?
Because we are of the same stock Thomas. Eric.
try one brick up on the mess wire
When I watched and saw you were going to use a chisel and hammer to cut the block first thought was they are going to break and well...
😃 Eric.
Thar is so funny
Good video!
Do either one create poisonous gases that are harmful to breathe?
Lol love it smart guy
@Garden Fork, the second method is much too hard and over my head. Looks good and admirable though.
You can do it!
You need a draft, better off using the masonry brick you broke in half. Can create the draft needed for air, put it in middle. With other mason brick on top. Weight holds it together. Watched others use this way. USe what you got!
Missed you.
I’m back!
“RocketMAN” - Elton John
One gal used 2 pavers and a brick in lieu of the H block.
A Masonry Blade on a Rotary Skill Saw would cut, or Score the Blocks , or Bricks easily....
Orrr you could use open ended blocks like the lady on living on a dime did here on youtube
your bottom cinder block is wrong
Who else like to watch his videos..
Brick!
With the bull shit in Texas I ain't the one
Nobody around here sells H blocks!🤬🤬
Hi. See Live Simple, Live Free. Rocket stove build. No saws.required. Peace to you and yours
Thank you 🙏
Block....to much work....brick...easy
Your stoves suck - I've worked masonry for over 35 years. You had one block (8.8.16) with a slot in it. That slot is for opening the end. With a masonry trowel (or chisel) you can cut the thin center out then cut along the edges to remove the two pieces on the end. With a little time and heat the blocks will crumble. With bricks you need to use fire brick.