New to Rocket Stoves 4" Beginner Build from Canada.

Hello all,


I am new to rocket stoves, about 1 month of experience. and I have started to put together a little stove/heater. I live in the city and would like to do some outdoor cooking as well as keep warm up my back deck. My main goal with this build is to keep costs down and make it light weight. Maybe later, after I gain experience, I will build an 8" rocket mass heater to heat my future log cabin in the woods with internet.

Being in a city my neighbors are of a concern. Keeping the smoke to a minimum and justifiably cooking on the stove/heater will keep things legal.

Here is my 4" build process so far. I have spent about $80 on bricks, $10 on a barrel, $30 on perlite, and $8 on clay based non clumping cat litter. Thats about $100 US.

Why am I using Cat Litter?



Because it is cheap and I wanted to see if it would hold up as a refractory insulation. There was very little information on the internet on using this type of clay, and I wanted to see for myself if this material could do the job. Compared to fireclay the cost difference is huge. Not to mention it has proven odor control, and stays fresh 4 life.

Burn tunnel and heat riser constriction:


Packing insulation into the mold around burn tunnel:


More insulation and exhaust construction:


Brick exhaust housing built and heat riser insulated. Removed all mold, insulation is still a bit wet:


Insulation dry, and chicken wire wrapped around heat riser insulation because I dont know how the Cat litter will react to the heat and at least if chunks crack off they will be contained close to the heat riser. We will see.


Close up of insulation.




Burn chamber and metal screen to allow air flow below fire:


Heat riser:


Exhaust comes out of the barrel here:


to be continued....

Steve Harvey : Welcome to Permies.com, our sister site Richsoil.com, and a big Welcome to our Rocket, Wood stove and Cob Forum threads .

couple of things to start kinda in reverse order ! See Link below :

http://www.louispage.com/blog/bid/23446/Chicken-Wire-Fabrication-Video

this was what most of us meant by chicken wire- sorry for the confusion is that aluminum ?

2nd link below to help navigate the site :


https://permies.com/t/43625/introductions/Universal


Shift through these and we can do much more ! Big AL

It may be aluminum, never really thought about it. Whatever it is it is home depot special, and may not last. Although I doubt that the outside of the insulation on my heat riser will ever see 1200F temperatures to melt it. I am hoping it won't even be required and the insulation holds up to the temperatures. In that case the wire mesh can be sacrificial.

Steve Harvey wrote:
Why am I using Cat Litter?

Because it is cheap and I wanted to see if it would hold up as a refractory insulation. There was very little information on the internet on using this type of clay, and I wanted to see for myself if this material could do the job. Compared to fireclay the cost difference is huge. Not to mention it has proven odor control, and stays fresh 4 life.

What else did you add too the cat litter "slip" ? The refractory material would be perelite or vermiculite - as an insulator - cat litter by itself might loose too much heat giving you poor performance. . .

I had some give me a bunch of 4 inch duct working from their dryer . . have not gotten around too doing anything with it though . . keep us updated on your micro rocket.

The cat litter clay is not the most ideal thing to use, but if trying to build something under $150 it is good enough. The colour of the clay when wet was similar to what you had in your picture Dave, So it should hold up the same as naturally found clay. One thing I would have done differently is strain the litter after soaking it for a few weeks to get the undissolved parts out. Although, I have read that a 4" systems don't work very well, so I guess we will see if my over insulating the tunnel and riser will make any difference, and get some performance out of this thing. If I was to make one for indoors I would go 8" and use the good quality materials and spend a lot more on it. Due to the fact that I don't want to void my home insurance I have been in talks with a certified masonry heater builder, and may get a small masonry heater built in my small 1200 sq ft. house, in the future. But for now it is experimenting with rocket mass heaters.

Something similar to this.



I used perlite with it to make the insulation. I didn't do anything special to the clay just mixed it with some pieces of scrap wood.

I also confirmed that the wire mesh is galvanized not aluminium, so it should be fine.

Massonry heater? Batch rocket!

He will apparently lose his home insurance if he doesn't have someone officially certified build his heater... good racket.

Glenn Herbert wrote:He will apparently lose his home insurance if he doesn't have someone officially certified build his heater... good racket.

Ontario is very strict with wood burning fireplaces and a lot of insurance companies do not want to insure houses that have wood stoves.


Insurance Issues

There are five points the insurance company will be concerned with:

Is it an approved unit? It should be certified by Underwriters' Laboratories of Canada (ULC), The Canadian Standard Association (CSA) or Warnock Hersey.
Did a professional install it?
Was a building permit issued?
Are the clearances up to the latest Building Code and Fire Code? There is no "grand fathering" of this requirement.
Is the venting system proper? Ideally there should be no elbows in the stovepipe and it should be as short as possible.
Having a properly installed wood heat system and making it safer means the best possible premium for insurance coverage. You should inform your insurance company or broker whenever a change is made to the wood heat system. This includes adding or changing a wood stove, modifying a chimney - anything that may influence the safety of the wood heat system.

Safety
There are a number of basic safety steps required for the proper maintenance of a wood burning appliance you should also be aware of.

Have it cleaned on a regular basis.
Inspect it at least twice a year for corrosion.
Have a smoke detector and a fire extinguisher nearby.

Source: CREA

Promoting safety is one thing, restricting innovation is another. They don't have to go together, but it is easier for the officials if they do.

Steve Harvey wrote:

Glenn Herbert wrote:He will apparently lose his home insurance if he doesn't have someone officially certified build his heater... good racket.

Ontario is very strict with wood burning fireplaces and a lot of insurance companies do not want to insure houses that have wood stoves.

Tell me about it, I am still trying to find somone to w.e.t.t. certify my rocket stove.

Now I really wish I had gotten my WETT cert. I could be a RMH certifier!

I cut my barrel today. The gaps will be packed with cob to seal them up.

Steve Harvey wrote:Hello all,

Exhaust comes out of the barrel here:

Anyone else think this is too small?

Depends on how far from the wire mesh the external barrel rim sits. If it is very near or on the outer brick, the fact that the airflow will be entering the channel straight on instead of turning to enter may make it okay. I do think it would be better if the upper opening was wider and funnel-shaped.

Roy Hinkley wrote:

Steve Harvey wrote:Hello all,

Exhaust comes out of the barrel here:

Anyone else think this is too small?

It is 4x4" because it is a 4" rocket stove.

Glenn Herbert wrote:Depends on how far from the wire mesh the external barrel rim sits. If it is very near or on the outer brick, the fact that the airflow will be entering the channel straight on instead of turning to enter may make it okay. I do think it would be better if the upper opening was wider and funnel-shaped.

The barrel lip extends now further to the edge of the outer brick, I just had to shimmy it a bit.

I would also like to share a cool discovery I made today.

I used an Antique glass insulator and a 10 watt LED round focus led, and it makes a really cool desk lamp. It is running off a 12v battery, and would light for 36 hrs before that battery would be 30% depleted and needed to be recharged. The battery is my emergency back up battery for power outages.





I will also share this in the solar energy section off the forum.

How close is that barrel going to be to the wall when finished? In the picture it looks way, way to close for my comfort.

Erik Weaver wrote:How close is that barrel going to be to the wall when finished? In the picture it looks way, way to close for my comfort.

on the other side of the wall outside in the back yard on the deck. If I were to build one inside I would make it larger.

If I was to build a rocket stove for inside use, would it not be better to get engineered plans from someone who successfully received a building permit for their rocket stove, and just copy that design. I know copying is not cool, and you should be artistic with your rocket stove, but...., If there is a design that works particularly well why hasn't someone made engineer certified plans someone could buy and take to there building department and get a permit to build?

You would have to get your plans certified by an engineer anyway, in order to get a permit would you not? and that would be expensive.

What type of engineer could I get to make Certified plans?

The closest you are likely to find:
http://www.ernieanderica.info/
I haven't heard of any licensed engineers certifying a RMH design, though one certainly could. There are always individual factors in any installation, so it is unlikely you could take one and precisely duplicate it.

http://www.ernieanderica.info/rocketmassheaterpermitting

Glenn Herbert wrote:The closest you are likely to find:
http://www.ernieanderica.info/
I haven't heard of any licensed engineers certifying a RMH design, though one certainly could. There are always individual factors in any installation, so it is unlikely you could take one and precisely duplicate it.

http://www.ernieanderica.info/rocketmassheaterpermitting

Thanks Glen, I will read up on this, Also, I was reading up on the 6" annex and it says they used old fired clay brick like Terra Cotta brick. Do these bricks work well for an indoor rocket stove? There are a few people getting rid of these around me.

They can be used for pretty much any part of an RMH. They will probably have a shorter lifespan in the burn tunnel and heat riser than firebrick, for a well-built and insulated core which will reach higher temperatures than early RMH models. If you have a large cheap supply of them, and will be able and willing to check and possibly rebuild the core in a few years, I think it would be worth doing. Getting the design right with cheap materials will let you build with confidence when you have more expensive materials.

right now I have built up my heat riser so it is about 2 1/2" to 2 3/4" from the top of the barrel. Should I leave it as is, or build up the extra 3/4" with a fireclay and sand around the top so it is exactly 2"?

2" gap is a suggested minimum for an 8" core; a larger gap will cause no problems. A really large gap will shift the hottest part of the barrel surface down the side a bit, which is only a problem if you want to grill on the top of your barrel.

For getting rid of the paint on my barrel, I can not burn it off because of the fumes that would go with it, and close neighbors. how hard is it to get the paint off with a wire wheel and grinder? Or could I use paint thinner for the paint inside the barrel?

I'm not sure how hard your paint will be... a wire wheel is a common method, but I have heard of some super paints that are resistant to even that. Paint thinner may well be a dirtier, nastier method, and some liner paints may be resistant to it. Do some tests to find out!

So, I tried grinding the paint off the inside of the barrel, it worked, but was a very slow process. I managed to get the best results with a grinding disc, but it was still slow going. I managed to get about half the paint off, and I am thinking an electric sander with 40 grit sand paper will be a better option to try. Burning it off would be a lot easier, but I do not have a large enough property to do this.

I have started to sculpt the cob base around the bottom of the barrel, and it is going well. I also managed to get a really nice stainless steel cart to build the whole rocket mass heater on, which gives the stove a nice big air gap below, and hopefully the stainless steel will give off some radiant heat as well. It is easy to maneuver this cart, and when complete and in place I will loose stack bricks around it, so that the rocket stove is easily transportable if I want to move it.

I lit a small fire in it with some very dry tree branches and ran it without a chimney for about 30 seconds, it took about a 4 inch piece of news paper get the sticks lit, and was drafting after a few second. pretty impressive for a rocket without a chimney. Unfortunately I could not run it for more than 30 seconds because I did not want to smoke up my living room. I did manage to see a bit of smoke poof up from the burn chamber but then get sucked back in shortly after. I will run it longer and monitor the performance once I get this thing vented.

My dog has never seen cob before, and had to investigate it closely, she also wasn't very pleased that she was not aloud to chew the firewood.







I have also switched to air floated fire clay for the 1st layer of cob. Cat litter will not cut it. It worked fine for the insulation, but wasn't smooth enough. I will be using found clay for the structural layer of cob.

After along time of procrastination, I managed to get my stove outside for the first test burn. It works really well, It starts drafting quickly, and I have managed to cook two meals on it using firewood I gathered on my dog walks in the woods. I plan to go further with this by adding a barrel, but I have not had the time or place to safely burn the paint off my barrel. I spent the day today constructing a temporary pallet structure/weather barrier for the rocket stove on my deck. As you can see in the video, my townhouse complex is not ideal for such an eyesore of a rocket stove/pallet shanty village, but its a free hold town home, and I can do whatever I want. HA! In the video you can see how nicely the stove is drafting, and there is no visible smoke out the chimney. I am very happy with my rocket, and hope the addition of a barrel will help with radiating some heat. I must add that winter is around the corner here, and the snow will be very heavy where I am. I built the pallet shelter simply to protect against wind, rain and snow. I have a roof to put over it when it is not in use, and I do not plan on leaving the structure up in the spring and summer. After I get the barrel on and the rest of the cob finished I plan on water proofing the cob with wax and the shanty village will no longer be required. I know it is not the most visually pleasing shelter but it was free and thrown together in an afternoon.

Steve Harvey wrote:

Roy Hinkley wrote:

Steve Harvey wrote:Hello all,

Exhaust comes out of the barrel here:

Anyone else think this is too small?

It is 4x4" because it is a 4" rocket stove.

I had a bit of a time figuring out the size of my system as well, since you have to figure out the inside of a circle (math problem ! ) and then transfer that size of space too fit inside a square (math problem !) That way, the size of the system is consistent from start to finish . .
For my system I believe it worked out too 5.5 x 5.5 for a 6 inch system . . so pretty close . .

Steve Harvey wrote:
For getting rid of the paint on my barrel, I can not burn it off because of the fumes that would go with it, and close neighbors. how hard is it to get the paint off with a wire wheel and grinder? Or could I use paint thinner for the paint inside the barrel?

Just a suggestion here, go too your local head stone - dealer. .
The one I went too also happens too be at the graveyard . .
They sandblasted both my barrels for a small fee . .

I'm also in ontario, and in development of my first rocket. My brother came down to visit around christmas, he's a home builder, framer, contractor. I was talking about my rocket and he mentioned that his friend is an engineer, and if he signs my design, I can legally build one indoors and apparently I could even tell the building inspector to go fly a kite, if I had the engineer approval.

I am still designing and testing and developing, and I still have many hours of burn tests and perfecting to do yet. But maybe you might find some of this info useful. I don't plan on being ready for residential installations for a while yet, but its good info to know, and good to have those connections if need be.

John McDoodle wrote:I'm also in ontario, and in development of my first rocket. My brother came down to visit around christmas, he's a home builder, framer, contractor. I was talking about my rocket and he mentioned that his friend is an engineer, and if he signs my design, I can legally build one indoors and apparently I could even tell the building inspector to go fly a kite, if I had the engineer approval.

I am still designing and testing and developing, and I still have many hours of burn tests and perfecting to do yet. But maybe you might find some of this info useful. I don't plan on being ready for residential installations for a while yet, but its good info to know, and good to have those connections if need be.

That is exactly the key point about getting a RMH certified, getting an engineer to sign the plans. Most don't want to because they would be accepting liability for its safety. I have talked to a masonry stove builder, and he said he could build one and get it certified as a masonry heater.

The stove burns a lot better as a rocket stove instead of a Rocket mass heater. I finally got the barrel on, and tried a test burn, using a piece of chimney pipe approximately 7 feet tall for the chimney, I did not like the result of this trial. I preferred the burn of the stove with the heat riser exposed directly to atmosphere, instead of exhausting through a chimney pipe. I found the exhaust was dirtier with the chimney, almost like the j tunnel was not getting hot enough to burn cleanly. I have drilled a hole about 4 inches in diameter, on the top of the barrel, kind of like the one I saw in a video at the Wheaton labs, which has an exhaust directly on top of the barrel. I think that stove gets used primarily as a cooking stove which mine is as well. It burns so clean through that 4" hole on top of the barrel, That I can not see any visible smoke or anything coming out of the heat riser. I can set my cast iron pot over the hole, on top of the barrel, and cook with it like a stove burner. I think I will keep it like this and make a close-able damper, so I can switch between using it as a RMH and a RS.

Steve Harvey wrote:I have drilled a hole about 4 inches in diameter, on the top of the barrel, kind of like the one I saw in a video at the Wheaton labs, which has an exhaust directly on top of the barrel.

Sorry to contradict you, but that particular barrel has a chimney pipe inside reaching down almost to the bottom of the barrel. So in the video it isn't just a hole in the lid of the barrel which vents to the outside. The sides of the barrel did get hot as well because of that low exhaust position.

are there not local brick and mortar, brick and mortar stores in canada?

saving money on fire clay by buying cat liter? although very interesting and i will follow to see how this works i must say fire clay should be able to be found for $8 to $15 for a 50lb bag locally and if you really have no local sources that sucks.

you have construction skills and do make a handsome little pocket rocket. i think the loss in draw when you put the bell on is from the lack of length and insulation of your smoke stack. increase that a bit and you may find some more draw.

dont get me started on natural freedom, regulations, and getting permissions from another man. ugh.

Peter van den Berg wrote:

Steve Harvey wrote:I have drilled a hole about 4 inches in diameter, on the top of the barrel, kind of like the one I saw in a video at the Wheaton labs, which has an exhaust directly on top of the barrel.

Sorry to contradict you, but that particular barrel has a chimney pipe inside reaching down almost to the bottom of the barrel. So in the video it isn't just a hole in the lid of the barrel which vents to the outside. The sides of the barrel did get hot as well because of that low exhaust position.

OK, interesting, no need to apologize, I appreciate the information. The hole I put in the top of my barrel is off set from the top of the heat riser so the direct heat from the riser is blasting against the metal barrel top. The heat from there is then directed to the hole in the top of the barrel which is used for cooking. The top and about 5 inches down from the top of the barrel get hot. The important thing is that it works as a cooker, the spent exhaust is clean, and it uses very little wood to cook dinner.

F Styles wrote:are there not local brick and mortar, brick and mortar stores in canada?

saving money on fire clay by buying cat liter? although very interesting and i will follow to see how this works i must say fire clay should be able to be found for $8 to $15 for a 50lb bag locally and if you really have no local sources that sucks.

you have construction skills and do make a handsome little pocket rocket. i think the loss in draw when you put the bell on is from the lack of length and insulation of your smoke stack. increase that a bit and you may find some more draw.

dont get me started on natural freedom, regulations, and getting permissions from another man. ugh.

I used the cat litter to see if it would work. It does, as long as it is the 100% clay kind, and you make slip out of it, and let it sit for a few days. The litter was 5 bucs for a medium sized bag and 10 for large. I bought fireclay here, it is about 40 bucs so a bit more than in the states.

I will have to wait until spring to do more testing on this stove. It is -15°C average temp here, and that surely effects the performance of my rocket stove.