# Homemade sand battery
**URL:** http://forum.driveonwood.com/t/homemade-sand-battery/7657
**Category:** Off Topic
**Created:** [January 26, 2024, 3:42pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657 "2024-01-26T15:42:44Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@tcholton717](http://forum.driveonwood.com/u/tcholton717)
#### Post date: [January 29, 2024, 6:29pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/21 "2024-01-29T18:29:58Z")
The process they go through in the stove video is pretty much what I have to do with my wood stove heater three times a year. Because it’s all designed around capturing heat in thermal mass with a convoluted smoke path it absorbs enough heat burning hot fires that the 30 foot long flue only gets to around 200-220F. Creates a crusty type of creosote that comes out easily with a regular chimney brush but will clog the flue if i don’t clean it, usually some time in December, then February and April. Looks real similar to what they were pulling out of that stove.
The heat riser in the Rocket mass heater in my greenhouse is a piece of 8 in black stove pipe lined with one inch of ceramic fiber blanket. [https://www.homedepot.com/p/UniTherm-Ceramic-Fiber-Insulation-Blanket-Roll-8-Density-2300-F-1in-x24in-x25ft-for-Kilns-Ovens-Furnaces-Forges-Stoves-CF8-1-24X25/305950070](https://www.homedepot.com/p/UniTherm-Ceramic-Fiber-Insulation-Blanket-Roll-8-Density-2300-F-1in-x24in-x25ft-for-Kilns-Ovens-Furnaces-Forges-Stoves-CF8-1-24X25/305950070) This stuff from Home Depot was cheaper than I could get it off Amazon. I’ve been running it for three years now with no problems. I’ll pull the barrel this spring to see if it needs to be replaced. I wish I would have back filled the bed with sand because it would have been so much easier but mine is mixed cob. It took a year of running the system to get it dry enough that water wasn’t leaking out between the gaps in the stone retaining wall. Cob was supposed to have superior heat storage capacity but I never saw any data comparing it to just sand. Way back when, glaubers salts was used for heat storage for passive solar systems. Haven’t heard that mentioned for a while but I don’t really research it much anymore. To anyone building a Rocket mass heater system I recommend upsizing your ducting if you are doing any length of bed. My bed is 18 foot long with a 16 foot run of 6 inch duct out and back. For that amount of length it should have been an 8 inch ducted system. With an 8 foot exit stack I have to run a duct fan to get the system drawing well enough to not smoke back from the fuel port. Lengthing the stack would help but I don’t want something 12 foot in the air. ,
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 6:52pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/22 "2024-01-29T18:52:18Z")
I have built the 5 min riser with this method… I tried to use sodium silicate to bind in the ceramic fibers from the insulation, as you don’t want to be breathing in those fibers…
Those who build kilns use this stuff and use a coating of something called “satanite”… to protect the fibers.
I have had the fibers break down, and was one of the reasons I moved over to solo stoves…
With the insulation in it does make the 8 inch riser into a 6 inch one…
I do prefer people use the Morgan Superwool instead of ceramic fiber if they can…
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 6:55pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/23 "2024-01-29T18:55:13Z")
I also run a group for rocket stoves on Gab…
> **[Rocket Stoves International · Group · Gab.com](https://gab.com/groups/80732)**
>
> Rocket Stoves International on Gab. All things rocket stoves and pyro mania. - The Home of Free Speech and the Parallel Economy. Join our community where people who support family, faith and free speech can speak freely and shop at businesses who...
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### Author:  [@madflower69](http://forum.driveonwood.com/u/madflower69)
#### Post date: [January 29, 2024, 7:36pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/24 "2024-01-29T19:36:54Z")
> [@ray\_menke](#):
>
> I recycled all my solar water heating hoses and schemes for heating water directly with the sun and pumping it to a large tank in favor of heating the water with the 3 used solar panels,
You -might- be able to repurpose the hoses to cool the backs of the solar panels. It bumps up their efficiency if they are cooler, and maybe pre-heat the water. It is like a 10-15% gain so the additional expense isn’t usually worth it, but in your case you may have the materials already. And it still might not be worth it. 🙂
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### Author:  [@Offgrid](http://forum.driveonwood.com/u/Offgrid)
#### Post date: [January 29, 2024, 7:38pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/25 "2024-01-29T19:38:26Z")
you might want to check out an old beek Farrington (SP?) Daniels, _Direct Use of Solar Energy_. He discusses using various salts and heating them and capturing the heat of fusion. I read it over four decades ago so my memory may be a little fuzzy.
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 7:40pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/26 "2024-01-29T19:40:46Z")
> [@Offgrid](#):
>
> Farrington (SP?) Daniels, _Direct Use of Solar Energy_
> **[Direct Use of the Sun's Energy: Daniels, Farrington, Baitsell, George A., Sloan,...](https://www.amazon.com/Direct-Suns-Energy-Farrington-Daniels/dp/4871877124)**
>
> Direct Use of the Sun's Energy \[Daniels, Farrington, Baitsell, George A., Sloan, Sam\] on Amazon.com. \*FREE\* shipping on qualifying offers. Direct Use of the Sun's Energy
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 7:48pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/27 "2024-01-29T19:48:43Z")
Using direct from solar panels to motors / heating elements led me down this trail…
[ ](https://www.youtube.com/watch?v=XobZXaqLCkE)
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 7:49pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/28 "2024-01-29T19:49:09Z")
Thanks for that link.
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### Author:  [@madflower69](http://forum.driveonwood.com/u/madflower69)
#### Post date: [January 29, 2024, 7:49pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/29 "2024-01-29T19:49:26Z")
> [@mart85](#):
>
> Those who build kilns use this stuff and use a coating of something called “satanite”… to protect the fibers.
It is similar to something 100 refractory wash/coating except I think it is cheaper but not cheap. 🙂
The Superwool, is still a potential class 2 carcinagin according to their documentation for Europe. I wouldn’t leave it uncoated or breathe it anymore then any other wool material. It may not break down as fast though.
what do you use solo stoves for? I was just looking at making one out a 55 gallon drum to essentially boil water. 🙂
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 7:53pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/30 "2024-01-29T19:53:30Z")
I figured out that if you put a tray on top of the solo stove a try of sand in an insulated 55 gal barrel you can cook pizza in about 15 min. I put a cast iron pan sheet ment to go on charcoal grills on top of the sand, and the heat in that barrel cooks pizza FAST. but with the sand and cast iron it is even heat so no burnt spots unless you are slow. 🙂
The best part of this is you get smoked pizza, the smoke of the burning oak is in the crust…
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### Author:  [@ForbiddenTuna](http://forum.driveonwood.com/u/ForbiddenTuna)
#### Post date: [January 29, 2024, 7:53pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/31 "2024-01-29T19:53:57Z")
> [@madflower69](#):
>
> The Superwool, is still a potential class 2 carcinagin according to their documentation for Europe. I wouldn’t leave it uncoated or breathe it anymore then any other wool material. It may not break down as fast though.
Definitely use some Sodium Silicate to keep it from shedding. Just handling superwool releases the crud. It’s fiberglass wool on steroids. Gloves, Goggles, and Mask are a must.
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### Author:  [@Offgrid](http://forum.driveonwood.com/u/Offgrid)
#### Post date: [January 29, 2024, 8:05pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/32 "2024-01-29T20:05:56Z")
That is the book. Like I said it was a long time ago I read it. Some is dated info but other info is still useful. I checked my library and it is still there. Should have checked before I responded to you and I would have had the title correct.
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### Author:  [@madflower69](http://forum.driveonwood.com/u/madflower69)
#### Post date: [January 29, 2024, 8:11pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/33 "2024-01-29T20:11:30Z")
> [@mart85](#):
>
> The best part of this is you get smoked pizza, the smoke of the burning oak is in the crust
I thought solo stoves were supposed to be essentially smoke free?
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 9:18pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/34 "2024-01-29T21:18:40Z")
They are unless you put it directly under a pan of 1/2 inch sand, or when they are first starting up. Until that sand gets up to temp or the canister heats up it is putting off smoke.
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### Author:  [@madflower69](http://forum.driveonwood.com/u/madflower69)
#### Post date: [January 29, 2024, 9:34pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/35 "2024-01-29T21:34:09Z")
> [@mart85](#):
>
> They are unless you put it directly under a pan of 1/2 inch sand,
how far is directly? I need a pot which is essentially the same thing as the pan. If the support system gets too high. I might be better off going a different route. 🙂
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 29, 2024, 9:44pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/36 "2024-01-29T21:44:56Z")
The distance makes all the difference… 3 1/2 inches from the top of my solo to the bottom of the pan…
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 30, 2024, 12:51am UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/37 "2024-01-30T00:51:33Z")
Thank you for that info… I do believe that heat pumps combined with solar heating is the way to go…
I am going to pick up a kiln tomorrow I hope to convert it to run straight from my solar panels… But not sure I want to do that as I want to melt alum… I have lots to learn.
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### Author:  [@madflower69](http://forum.driveonwood.com/u/madflower69)
#### Post date: [January 30, 2024, 1:22am UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/38 "2024-01-30T01:22:55Z")
> [@mart85](#):
>
> I am going to pick up a kiln tomorrow I hope to convert it to run straight from my solar panels… But not sure I want to do that as I want to melt alum… I have lots to learn.
If you are just melting aluminum you can just use char inside the furnace and blow air on it to get it to melt. I was originally looking at a gasifier and blowing the gas to the furnace, and actually that would take care of my boiling issue as well. But I need a chunker to get more even pieces of wood.
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### Author:  [@mart85](http://forum.driveonwood.com/u/mart85)
#### Post date: [January 30, 2024, 4:43pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/39 "2024-01-30T16:43:46Z")
I just bought this… and it runs off my solar system YIPPIE !!! it pulls 1600 watts and it is up to 1000 deg now and climbing.
New toy 🙂 I found this kiln on craigslist for $50.00 It is pulling 1600 watts and is running now on my 2000 watt inverter… Looks like I can now do some melting of aluminum with this setup. Woo hoo! I have been planning on using my 3d printer with wax printing.
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### Author:  [@madflower69](http://forum.driveonwood.com/u/madflower69)
#### Post date: [January 30, 2024, 5:34pm UTC](http://forum.driveonwood.com/t/homemade-sand-battery/7657/40 "2024-01-30T17:34:40Z")
that is a great deal even if you didn’t immediately want one.
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