Instructables

back packing sauna problem. i want to make a portable heat and steam source for a small 2 man tent sized sauna?

i am trying to design a lightweight portable steamer for a back packing sauna. i do not want to use hot rocks as this is time consuming an the rocks are not always available. idealy the heat source would be outside of the sauna and the steam piped in. i am not sure how much water it is going to take, which means i may have to have some way keeping the boiler etc topped up from a plastic container. i have considered using a conventional wood burning stove with a coil of copper pipe within but cannot get my head around how this would work with out a  kettle type reservoir to hear the water, if the water was just heated in the copper pipe coil fed from a lightweight water container i would imagine i would then need much less heat, help please.

skaar2 years ago
tea kettle with some silicone hose stuck to it, pipe the steam from the fire, where the kettle is. it could even be possible to set up a hung container of water, open a valve, water runs back through the tube to replenish the kettle, probably best through a T, so there's less risk of getting scalded. could run for hours... days... have time for dozens of visitors... when not steaming yourself, route it to a container of stainless steel potscrubbers so distilled hot water for coffee drips out.

anyway, some tea candles and a soup can would do as well, if slowly, one of the kind with sealed bottom, a hammered sheet lid with a rock in it to keep it from just evaporating. hang the assembly from the ridge pole or something, two since it'd take time to heat.
robertuk444 (author)  skaar2 years ago
Thanks for your comments. the kettle idea is what i am considering, but due to the amount of steam needed i would need to be able to top up the water on a regular basis. this could be done from inside the sauna and as you sugest through a tube with a t piece, the problem with that is not knowing what the level is in the kettle. topping the kettle from a hung container is preferable but again the level needs to be maintained, i thought i might chance it and drip feed the water into the kettle but that leaves everthing to guess work on how much water is going to be neede to maintain the level or i need some sort of float valve that is heat resistant. in addition to all that i have to be mindful of weight as i need to back pack with it.
there, fixed.
same principle as a water level, stick two bits of clear tube on the end of a hose, fill it with water. if there's no water in the tank, there' s no water in the tube.

the tube in the fire should be rather robust stuff, steel brake line would do, all the rest could be relatively light plastic, including the valve. if the melting temp of the stuff in contact with the water is above 100c, shouldn't be much of a problem, and lighter than metal. the metal tube has a curveback at the top to keep it from spitting, would also do percolator duty. high temp tubing between the tank and coil, though even garden hose can take a serious hit of heat before it gets funky, and it won't be under pressure. a check might be good near the valve.

i'm pretty sure a milk jug has a high enough melting temperature that it'd survive quite handily. on the exhaust side rubber hose will be ok, but the rest of that side will be at steam temps, so, no plastic.
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canucksgirl2 years ago
First of all, where exactly will you go that you won't encounter rocks? Our family is from Finland, and we grew up with a sauna and I bet I've been in one a thousand times. My dad also made a portable sauna, but I can't get into how he made it, because that's his project.

To achieve what you're looking to do, you should refer to the methods that Native Indians used in making a "sweat lodge". They would use buffalo hides for the domed "tent" structure. In place of the hide, I would use wool blankets versus a regular tent. They aren't designed for that kind of heat, nor will they hold much heat.

For the heat and steam, you only need to build a fire and add rocks until they are very hot. Use a shovel to transfer the rocks to the center of your 'wool tent' and then add water for steam. If you can heat water on your fire, your rocks will stay warmer longer than if you used ice cold water from a stream.

I don't recommend the method you're proposing as it presents more of a fire risk than its worth.
robertuk444 (author)  canucksgirl2 years ago
I understand how it works with the use if rocks and have used saunas with that method. there are plenty of places i trek that where open fires are not allowed also building a subtantial fire and heating the rocks is very time consuming, so hence the need for some sort of portable steam generator. with regard to the construction of the sauna. it is well insulated i am not using just a tent. the two man tent discription was used to give an idea of the size for the amount of steam i am going to need.
Fair enough, but we do have to take what you ask into consideration... that being said, I'm guessing you don't want to trek in fuel; so you'd need to look at making this a wood heater, and utilize whatever you have at hand. If the stove is outside your structure, there would have to be a large enough boiler to heat water to create enough steam. So consider making something cylindrical, and have the stove at the base, and the water reservoir on top, in a single unit. You'll have to weld a pipe near the top, out the side and with a flex pipe, you should be able to run this into your structure. The size of your heater will be largely determined on the size of your structure and how well insulated it is. To keep this system running, you'll also need to vent from the floor at one side and at the roof line on the opposing side. How you do this also depends on your structure. Testing this system will be key in determining how well it will work, but if done right, it can run in any temperature. (We run our portable sauna in temperatures well below zero and inside its blazing hot). :)
I would think it would be easy to use something like a pressure cooker with the copper pipeing ran into the "tent" to deliver the steam. On a smaller scale eve a teapot could be used once you have the connection part fixed. Add water, place on woodstove or other heat sorce your useing, once it starts to boil you get the steam delivered. Can't get much simpler.
robertuk444 (author)  RedneckEngineer2 years ago
Hi pressure cooker is a good idea but maybe a bit heavy and big for back packing, and kettle small. i shall be carrying with me a collapsable plastic water container which will hold around 15 liters of water if i could continually supply a small boiler/kettle with some sort of valve as to replace the water as converts to steam in the boiling container or perhaps feed the water straight into a coiled pipe that is placed on or in my wood burnig stove, i am not sure what valves would be available for this purpose other than a small ballcock. will welcome you feed back. thanks
rickharris2 years ago
Having ANY sort of open heat in a tent is not a good idea - End of project i am afraid. tents BURN.
robertuk444 (author)  rickharris2 years ago
I have no desire to put the heat source inside of the sauna hence the need for some sort of steam generator.
Not to forget asphyxiation as oxygen is used up in a small enclosed space.

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