I’m building a portable wet sauna which basically has a large pot of water inside a small enclosure that boils water and produces steam. I’m using PE (polyethylene ) plastic as the cover to our enclosure and it sits as close as 12 inches above the water pot and thus is in almost direct contact with steam. Is this safe?
Wikipedia indicates the melting temperature of PE plastic as either 105 to 115 degrees celsius for low density PE and 120 to 130 degreea celsius for medium or high density PE. Water boils at 100 degrees celsius.
Does that mean the plastic won’t melt at that temp as steam is same temp as boiling water and so we’re safe from any off gassing or fumes from the plastic as ita below its melting temp? At what temp does heating PE plastic become toxic or unsafe, below, at or above its melting temp?
I’m imagining it would have to burn in order to release toxic fumes but id rather be safe than sorry…
Also this pot of water is not pressurized and I know steam has same temp as boiling water at 100 degrees celsius but it has a higher heat energy. Does this mean steam could melt the plastic, when even submerging plastic in boiling water would not?
Thx all!
I’m also open to suggestions for a non toxic heat shield or insulation that i can put on the inside of enclosure, above ateam and under the pe plastic that will protect theplastic from almost direct contact with high temp steam.
Hi, You ever seen plastic boiling vessels in the stores? Loads around.
Kettles, camp boilers, geysers to sit over the sink, all sorts of stuff. Some are nylon, some are polyethylene, some are polypropylene.
Steam gives up it’s heat easier because of the increased surface area of the steam drops compared to a solid body of water….haha, solid water…well, y’know what I mean.
If it’s not pressurised it’s exactly the same temp as boiling water when it comes off the top…cools a bit later but it won’t make things any hotter than boiling water will…just heats them quicker.
Kettle lids do OK in the steam a couple of inches above the boiling water….no problem in your set-up if it’s thick enough and doesn’t simply distort with the heat coming from one side.
You won’t get toxic gases off it at 100C. Gets toxic way above that.
You can get electric pots for French fries and battered fish etc made of polyethylene (the pot..not the fish….oops)…fry stuff at 180C in those. Best at 160C for fries.
The plastic casing gets hotter than boiling water on the inside of most of them.
For a cover you could use nylon sheeting if you can find some or acrylic sheets obtainable from DIY stores and often used for plastic greenhouses and for barn windows and skylights. Heat it to get it soft enough to bend.
Wood has it’s uses too but some knowledge is required when using it in saunas. Perfect excuse for a fact-finding mission to Finland, home of the world masters of wood and water makes glorious living and looks swell too without swelling the wood.
Iceland is closer and rather good at it and it’s a pretty cool place to visit and a bit cheaper after their currency crashed. OK at this time of year, but take a breathing mask if you’re staying south.
http://www.finnleo.com/images/11ADecoIntA.jpg . . . . .
http://img.archiexpo.com/images_ae/photo-g/finnish-sauna-124453.jpg . . . . .
http://peacecountry0.tripod.com/sauna.htm . . . . . .