Kapok vs. Down

[Martti]

During the 1940s U.S. Antarctic Service used waterproofed kapok mattress. I have seen also advertisements for kapok or "tropal" lined jackets in various 1940s magazines. Kapok is nowadays, however, used mostly on stuffing, as far as I can see. I wonder why the situation is as it is. Depending of the source, the thermal conductivity of kapok ranges from 0.034 to 0.035 W/(m.K) and eiderdown's from 0.019 to 0.045 W/(m.K). The density for both are 14.1 kg/m³ and 2.2 - 110 kg/m³ respectively. The largest difference is however the price: the price of kilogram of kapok fibre is only about 1/10 of that of goose down!

According to this 2009 study made in Sweden, there was no statistical difference between coats filled with almost the same amount of kapok and duckling down.

 

[mountainm]

Perhaps Kapok doesn't loft as well as down so loses it's insulation ability quicker when compressed.

 

[Martti]

Perhaps Kapok doesn't loft as well as down so loses it's insulation ability quicker when compressed.

According to one study, kapok resists compression very well, better than goose down it seems. However it does not bounce back as well as down.

 

[Toddy]

It's simple; it's a nightmare to keep it confined, and a bigger one to keep the covering dry and free from mildew

My lifejacket as a child was stuffed with kapok, and it had a ventile like coating to stop the stuff escaping.
Used to stuff cushions it is sewn into very tightly woven ticking. The fabric covering usually negated the lightweight benefits but it is very water resistant and dries much more quickly than down.

It's a lovely fibre, does loft up, (with a shake ) and it's not smelly like down can be, nor does it seem to attract moths, etc., but open a bag to use, and you'll need to hoover the house , yourself, the cat, the furniture........it gets everywhere with the slightest movement or draught.

Not agin it, just it has problems that aren't always easily overcome. The fibres are almost wax coated, and any chemical process that damages that coating, more or less ruins the properties that the fibre is best used for.
So, dyeing, spinning, weaving all need particular care, and even then they do alter the fibres.

cheers,
Toddy

 

[Martti]

Apperently the 1953 Everest expedition used boots insulated with kapok. A pair weighted only 4 lb. 4 oz. (1.9 kg) and none of the climbers suffered from cold feet.

 

[Toddy]

I wonder what they used to confine it ? Seriously, it is a lovely fibre, but it wicks away to the fabric covering and unless you get that right, and find a way to dry it, that gets mildewed and the mildew eventually rots the kapok too.

Interesting article, it says that they totally surrounded the kapok with a waterproof membrane so that the insulation could not be compromised, and that wet feet, so long as they were warm, were considered acceptable.

I know I found it comes through the stitching on ripstop nylon, I had to seamseal the stitches to stop it escaping.

Tengu had a load of it, I wonder how she got on with it.

cheers,
Toddy

 

[redandshane]

I was just about to say that the No1 collector of strange but useful items Tengu was offering this at one point
but Toddy beat me to it
No doubt Tengu will be along in due course

 

[Laurentius]

I remember having a cheap Kapok lined sleeping bag many years, complete with waterproofed underside that served as it's own groundsheet. (which eventually delaminated ) I think kapok was used at the cheap end of the market before artificial fillings became widespread. I also recall that it was not very warm. Kapok lined arctic coats were also commonly available on the surplus market. I'm talking early 1970's here.

 

[andybysea]

The ww2 denison sleeping bag's were kapok filled if i remember correctly,

http://www.worldwarwonders.co.uk/WW...-Denison-Material-Sleeping-Bag.html?Itemid=59

 

[Jessy11]

For most people, the kapok fibre minimizes the potential of allergic reactions. (But it is a natural material and may cause an allergic reaction in some people.)

 

[Stringmaker]

I recently discovered that kapok is a fantastic primary tinder for taking a spark.

You lot probably already knew that...

 

[Toddy]

Have you tried making cordage with it ? and then tried to use it like matchcord ?
It occurs to me that it might be very good

cheers,
Toddy

 

[Stringmaker]

Have you tried making cordage with it ? and then tried to use it like matchcord ?
It occurs to me that it might be very good

cheers,
Toddy

Good idea.

It will twist up into cord really easily; I'll have to try it.