True "warm while wet" material–open celled polyurethane foam for cold temps?

[Anonymous]

I just recently and serendipitously stumbled upon the concept of using open celled polyurethane foam for extreme cold temp use, as well as possible exposure to water.  There’s a bunch of youtube videos where people wearing foam clothing jump into holes in frozen over lakes, into streams, etc while it’s cold outside.  One guy, ended up going in like 2 more times after the initial time because he was warming up so fast in the foam clothing.  As soon as the water started to drain out of the foam, they would start to feel warm again (and it apparently drains fairly fast, especially when squeezing or wringing it out).

The guy who pioneered and brought the concept to the public the most, Jim Phillips, extensively tested it and compared it to traditional insulation’s used for extreme cold.  Apparently, its far superior in some ways–mostly in it’s ability to handle moisture and keep a person warm and comfortable in a wide range of temps and conditions.  He says it’s very important to line it with very breathable, but quick drying fabrics.  A lot of the little companies that sell foam clothing, line either the inside or outside with a heavier duty mesh to allow it to breathe the most.

Course, like anything, it has some downsides–mainly it’s bulky and a bit heavy (though that somewhat depends on the density of foam being used and the fabrics lining it).  Some of the open celled foams aren’t that durable also, so you have to research which ones are more so.

Jim sells a “special” version of the foam on his site, which is pretty pricey.  He says that it’s superior to other foams in various ways, especially in resiliency, compressive recovery, air permeability, and overall durability.  Doing a little digging, i think what he is selling is most likely a lower density “Dry fast” foam, which is more expensive than a lot of other open celled polyurethane foams, but he’s marking it up some 200% (or more if he is buying it in bulk).

Some folks use it for everything, including sleeping gear.  I’m not sure i would go there because of the weight and bulk (well i would with using a Pulk or Pulk-Shelter), but making some clothes with it sounds pretty interesting and worthwhile if one plans to go to the Arctic or Antarctica. It seems like it would be especially advantageous to combine it with fishnet baselayer that has some Merino or especially Alpaca in it to help cut down on odor some, because i can imagine the foam getting pretty rank after awhile especially when right next to the skin.

A handful sources so far, say that to sew the 1 inch thick stuff (the thickness needed for Arctic like temps, except for feet which needs 1.5″) is nigh impossible with a regular sewing machine and you need an industrial machine.  1/2″ is ok to sew with a regular sewing machine these same folks say.

Anyways, any BPL folks who have used or know people who use it, and if so, what kind of foam?   I ask what kind of foam, because even within the open cell polyurethane foam category, there are various different versions.  I’m really surprised i haven’t heard of this earlier.  I briefly thought about using open celled foam before, but i assumed it would hold onto moisture too much.  I do think that needle punctured closed cell foam could be an alternative since it’s warmer per weight, and some kinds (like Evazote) are much tougher than most of the open celled foams.

[Richard Nisley]

The type of foam used for clothing is most commonly “Polyether Urethane Foam”.

You can try the clothing for yourself; believe the people selling it; buy a copy of the copyrighted research report entitled, “Moisture Transfer Through Impermeable Foam Insulations” by George F. Fonseca; or take my word for what the report says since I own a copy.

The research summary concluded that all of the foams, with perforation patterns, have similar low moisture permeability, even with the comparatively large open spaces of the foams which have porosities in the range of 40 to 50%. None of these foam systems shows as good as an environmental range as the typical fabric system.

[Anonymous]

Hi Richard,

The videos may not be “proof” of efficacy per se, but it’s very hard to fake lack of bodily reaction to severe chilling from immersion in very cold water and then being exposed to even colder air right after.  Teeth chattering, shivering, etc are all signs that show up pretty quickly, unless one learns and perfects the Wim Hof way (which scientists cannot adequately explain as of yet).   Going by these multiple videos, something must be happening and it seems not all the people doing the videos have a commercial or vested interest.

Do you know if specifically the “Dry Fast” foam was tested?  It’s hard to say without having handled it at all yet, but it seems that this version of foam is significantly more permeable than the other ones.  It was designed as a foam to be used outside for outside furniture etc, so that if it got rained on and soaked, it would drain faster and thus dry faster.

This version at least, may be worthwhile to do some testing with, unless you know for a fact that this version was already tested and shown to have low permeability?

As always, i appreciate your input and perspective.

 

 

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