Modern bushcraft !?!

[rg598]

Never had Merino wool, at least that I am aware of. But had plenty of wool base and mid layers and still use them.

But the main idea of wool is not that it will keep you dry, or wick away moisture. The idea is that even when it's wet it keeps around 70% of it's insulating capability. I.e it keeps you dry even when wet.
But wool takes it's time to dry to, and when wet it becomes even heavier than it already is. The thing with wool is that you accept that you are going to be wet anyway, so you use a base/mid layer that will still keep you warm when you are.

Modern materials is much better at wicking moisture out, they are lighter than wool also, and dry time is shorter. But they smell terrible from sweat, and lose much more of their insulating capabillity when they do get overwhelmed.

What to use must be up to each of us. We all have to walk our own hike.

See, I would love to see some data on that. In my experience, wool absolutely does not keep you warm when wet, and in fact keeps you as cold as fleece clothing. People keep saying that on forums, but I am yet to see a study that shows that.

As I said, for me bushcraft is a set of skills, and they can be used regardless of your choice of gear. I tried to stay out of the rest of the hoopla, but the whole wool keeps you warm when wet thing, just bothers me because in my experience it is absolutely not true, and I ma yet to see any verifiable data to confirm it.

 

[rg598]

I think I'll take the word of the Norwegians Army research institute, and SIFO over any random bloggers any day...

Wool will insulate you even if you do get wet. This is because it can absorb large ammounts of moisture compared to f.ex synthetic fibres. It can hold up to 35% moisture before it even starts to feel wet (depending on wool type). This means that a 100% wool sweater can suck upp up to 35% of it's own weight without feeling wet. In addition it will generate heat while absorbing moisture. This is why you feel dryer in wool, and is the reason why even moist wool clothes keep you warm.

Hello, random blogger here,

Could you please explain how feeling dry is the same as maintaining thermal insulation. As far as I know one has nothing to do with the other. You can feel dry all you want, but the material is losing heat at a much different rate. The fact that wool absorbs water effects the comfort level (it doesn't feel damp) but it does not change the reduction in insulation. The water is still in the material, and it still conducts heat much faster than still air. While heat loss due to evaporation is slowed down with wool because of the slow dryig time (spreads out the heat loss due to evaporation over longer time frame), the heat lost due to the increased thermal conductivity of the material is not. Still air has a thermal conductivity coefficient of 0.025 W/mk, water has a coefficient of 0.6. There is no way around it.

Also, can we see some of these studies everyone talks about? I've been searching for a while now, and I am yet to find any that let's say compare wool to fleece, or Primaloft One, etc. Let's see the data.

People say that wool keeps anywhere from 50% to 90% of its insulation when wet (depending on who you listen to), but I have not seen the source of that data anywhere. On top of that Polartech claims that their fleece retains similar amounts of insulation, and so does the Arcteryx version of Primaloft (80% according to them). Honestly, I don't believe any of their claims, but they seem to have more data to back it up that what I have seen with wool. I'm not saying it's not true, it would just be great to have a look at the data and evaluate it. We wouldn't want to fall prey to the latest marketing gimmick or forum trend.

Yours truly,

Random blogger

 

[rg598]

I would disagree, a woollen jumper does keep you warmer and in the early days of snorkelling a thick woolly jumper was used before wet suits came in, see Alexander McKee's book "Farming the Sea". There is a difference between an active body and a container of warm water.

There is something to be said for bare skin in the rain if the wind is not too great.

Please note that the test shows that DRY skin with no clothing will be warmer than WET wool, not that WET uncovered skin is better than WET wool. Wet wool will insulate better than being wet with no clothing. That however doesn't say much.

And... someone else mentioned that an active human body is different than a container of hot water. That is true in some respects, but not when it comes to measuring the thermal conductivity of an insulator.

 

[copper_head]

You might find this article interesting reading Ross. This Heat of Sorption is a new concept to me but goes a long way to explain why wool feels warm when wet.
My experience of wearing wet wool is that it does keep you warm, certainly warmer than just (dry) skin.
Just my 2'ps worth

 

[rg598]

You might find this article interesting reading Ross. This Heat of Sorption is a new concept to me but goes a long way to explain why wool feels warm when wet.
My experience of wearing wet wool is that it does keep you warm, certainly warmer than just (dry) skin.
Just my 2'ps worth

Thank you. That is an interesting study. It doesn't actually deal with the issue of whether wool retains any insulation and how much when wet. It seems to more directly deal with performance of wool when dry, i.e. when you are wearing dry wool clothing and the humidity level increases due to higher concentrations of water vapor, presumably from moisture being released from your body. The way I read it, the study shows that when water vapor passes through wool, and is absorbed by the fibers, it is turned into a liquid, releasing some heat in the process. I didn't see anything about the insulation of the materials itself. I'll try to find the articles in the bibliography and see if any of them are relevant. The article makes a lot of very general statements that seem very assured, but not a direct or indirect result of the study in the article. Good stuff though. Thank you.

The reason why I would rather see data is that we all have our experiences with wool, and they seem to be all over the place. Mine has been that it is no better at keeping me warm when wet than any other material I have worn in the woods. In fact, this past weekend I fell in some water. All of e was equally cold, the parts covered in wool and the parts covered in other materials. When I used to wear only wool clothing, I could immediately tell the change in insulation between the parts of my clothing that were dry and the ones that were wet. Our experiences seem to be completely different.

 

[rg598]

Here are some articles I have been able to find:

Comfort and Moisture Transport in Lightweight Wool and Synthetic Base Layers: http://www.keepandshare.com/doc/497...weight-wool-and-synthetic-base-layers-2-2-meg

The Effects of Protective Clothing on Energy Consumption During Different Activities: http://www.keepandshare.com/doc/497...-consumption-during-different-activities-407k

Some Practical Advice on Cold Weather Clothing: http://www.keepandshare.com/doc/4883520/some-practical-advice-on-cold-weather-clothing-850k

Benchmarking Functionality of Historical Cold Weather Clothing: Robert F. Scott, Roald Amundsen, George Mallory, by George Havenith, Department of Ergonomics (Human Sciences) Loughborough University: http://www.jfbi.org/admin/Issue/Proceedings of TBIS 2010_2010927112115_paper.pdf

Hopefully people can toss in some more. So far none of the articles have looked specifically at the percentage of heat retention of wet wool as compared to dry wool or as compared to other materials. I'm sure the studies are out there.

By the way, and I'm sure that this is something we will have to address when we get more data confirming the assertions, assuming 70% heat retention (I think someone here used that number), that is about 30% loss of insulation. That is significant heat loss. If you are wearing enough clothing to be thermally neutral (not cold, but also not overheating), losing 30% of your insulation will put you in serious trouble. I wouldn't call that keeping you warm when wet...again, pending actual data to support the numbers.

 

[copper_head]

Agreed that it doesn't deal directly with the retention of insulation. However the perception of the 'Heat of Sorption' mechanism does seem to give a explanation of peoples of experience (mine included) of wool as being warmer when wet. Some more reading for you .

 

[Bumbler]

Wet wool is not the same as water. Wools insulation capability is retained because of it's ability to trap air in the fabric while wet. And it is the trapped air that keeps you warm, provided your body is capable of heating it up. Cotton for example, loses this capability when wet. Same with down, which simply collapses, and with it's loft gone, it has zero insulating capability. This is why synthetic fiber sleeping bags perform better than down when wet. If your little test was supposed to be worth anything you would have to keep your heated conatiner at a constant temperature, and measure how much energy it took to keep the temperature constant.

The premise her is that the fabric is worn as a base layer next to the skin. If you wear wool as a base layer, the trapped air in the wool will heat up and keep you warm. And wool will still retain a large percentage of this capabillity, thus retaining the capability of keeping you warm. While f.ex cotton does not have this capability at all. It will only insulate you while dry, by trapping air inside the cotton layer, next to the skin, but when wet it clings to your skin, and with no air between your skin and the cotton, which has little or no air left in it also, your body will lose heat trying to heat up the water.
With wool you will not have this felt heat loss.

The finns you are refering to in your random blogger article, where probably wearing cotton clothing, but as an outer layer. And very likely with wool as a base and mid layer. Then it's okay, because wet cotton will trap air, as long as their base and / or mid layers maintain it's loft or capability of trapping still air, wich wool does. The cottons sole purpose is to act as a wind barries, to prevent the loss of the heated air.
And if it can be made water proof as well, itæ's added bonus, as keeping dry will add to the insulatuion capability of your base and mid layers.
You may try this. Wear a wool sweater in windy conditions. You will probably have significant heat loss. As the wind will remove all the trapped air in the wool. Add a wind proof layer and the problem is gone.

My uniform in the Norwegian army was f.ex all cotton. But the base layer was wool, allong with the mid layer if really cold.

 

[rg598]

Wet wool is not the same as water. Wools insulation capability is retained because of it's ability to trap air in the fabric while wet. And it is the trapped air that keeps you warm, provided your body is capable of heating it up. Cotton for example, loses this capability when wet. Same with down, which simply collapses, and with it's loft gone, it has zero insulating capability. This is why synthetic fiber sleeping bags perform better than down when wet. If your little test was supposed to be worth anything you would have to keep your heated conatiner at a constant temperature, and measure how much energy it took to keep the temperature constant.

The premise her is that the fabric is worn as a base layer next to the skin. If you wear wool as a base layer, the trapped air in the wool will heat up and keep you warm. And wool will still retain a large percentage of this capabillity, thus retaining the capability of keeping you warm. While f.ex cotton does not have this capability at all. It will only insulate you while dry, by trapping air inside the cotton layer, next to the skin, but when wet it clings to your skin, and with no air between your skin and the cotton, which has little or no air left in it also, your body will lose heat trying to heat up the water.
With wool you will not have this felt heat loss.

The finns you are refering to in your random blogger article, where probably wearing cotton clothing, but as an outer layer. And very likely with wool as a base and mid layer. Then it's okay, because wet cotton will trap air, as long as their base and / or mid layers maintain it's loft or capability of trapping still air, wich wool does. The cottons sole purpose is to act as a wind barries, to prevent the loss of the heated air.
And if it can be made water proof as well, itæ's added bonus, as keeping dry will add to the insulatuion capability of your base and mid layers.
You may try this. Wear a wool sweater in windy conditions. You will probably have significant heat loss. As the wind will remove all the trapped air in the wool. Add a wind proof layer and the problem is gone.

My uniform in the Norwegian army was f.ex all cotton. But the base layer was wool, allong with the mid layer if really cold.

Actually, "my little test" is not effected by by whether the container was kept warm or not. That has no effect on the thermal conductivity of the material. It doesn't seem to make sense to you, but from a physics stand point it's a fact. If the container was kept warm at a constant temperature, the lines of the graph would look different, but the gap between them would be the same.

As far as wool retaining air when wet, that is true but only in part. When wool absorbs water, the water displaces air from those structures. It is more or less a zero sum game. The more of that air gets displaced, the higher the conductivity coefficient of the fabric becomes, and the less it insulates. Even if no air is replaced (something which is not true), the mere presence of water in the material will increase the rate of heat loss due to the higher conductivity coefficient of water. Also, your assertions about cotton are incorrect, and are nothing more than a regurgitation of internet superstition. While cotton in some forms does not retain much of its insulative value when wet, that is not true of all cotton. The knit for example will have a huge effect on how much insulation it retains when wet.

And, no the Norwegian to whom I was referring was not speaking of cotton outers over wool insulation. He was talking about cotton insulation. You should read some of his stuff. Of course, that was not the basis of my test or conclusions.

Now, let's see some of your little studies. Like they say, talk is cheap.

 

[rg598]

Agreed that it doesn't deal directly with the retention of insulation. However the perception of the 'Heat of Sorption' mechanism does seem to give a explanation of peoples of experience (mine included) of wool as being warmer when wet. Some more reading for you .

I think you are exactly right about that. The second study confirms the results. Thanks for the reading. I appreciate it.

Now, I'm out. I'll read some more when I'm back in the office tomorrow (hopefully studies, not just diatribes trying to belittle my opinion or experiences).

 

[petrochemicals]

Hopefully to put the great wool war to bed -slightly damp wool is a good insulator ??????????? not soaking wet.

And a wet coat in the tropics is a far different effect than a wet coat in siberia.

 

[copper_head]

Hopefully to put the great wool war to bed -slightly damp wool is a good insulator ??????????? not soaking wet.

And a wet coat in the tropics is a far different effect than a wet coat in siberia.

, I wonder how well this insulates

 

[Bumbler]

Actually, "my little test" is not effected by by whether the container was kept warm or not. That has no effect on the thermal conductivity of the material. It doesn't seem to make sense to you, but from a physics stand point it's a fact. If the container was kept warm at a constant temperature, the lines of the graph would look different, but the gap between them would be the same.

As far as wool retaining air when wet, that is true but only in part. When wool absorbs water, the water displaces air from those structures. It is more or less a zero sum game. The more of that air gets displaced, the higher the conductivity coefficient of the fabric becomes, and the less it insulates. Even if no air is replaced (something which is not true), the mere presence of water in the material will increase the rate of heat loss due to the higher conductivity coefficient of water. Also, your assertions about cotton are incorrect, and are nothing more than a regurgitation of internet superstition. While cotton in some forms does not retain much of its insulative value when wet, that is not true of all cotton. The knit for example will have a huge effect on how much insulation it retains when wet.

And, no the Norwegian to whom I was referring was not speaking of cotton outers over wool insulation. He was talking about cotton insulation. You should read some of his stuff. Of course, that was not the basis of my test or conclusions.

Now, let's see some of your little studies. Like they say, talk is cheap.

I simply do not have the english and life is to short to make you understand that wool will trap more air than many other materials, even when wet, which is why it's insulation capabillity is kept to a much higer degree than f.ex cotton. If you do not understand this basic thing, then there is nothing I can tell you that will make you understand what I am talking about.

But you do mention the knit. What do you think traps the most air: A cotton shirt, or an equally thick wool garment?
And which of the two do you think retains most air trapped in the garment itself when moist?

Else I am not disputing that the pressence of water in the garments will increase heat loss. Of course they will. What I am saying is that wool retains it's insulation power due to it'ss ability to retain air trapped in the garment even when wet, while other insulations, collapse (down), or gets overwhelmed with water and traps no or little air.

If you do not understand this, then my english is exhaused and I simply cant explin it in a way you may understand.

 

[petrochemicals]

, I wonder how well this insulates

ha !

I see that this isn't the first time then. well you know what they say, do your research !

Also has anyone any experience with unspun cotton ?

 

[Bumbler]

Let me make one last attempt to make you understand. Wool absorbs water. This is one of the reasons it works so well, compared to artificial fibers wich are not so good at absorbing water. Beacuse the fibers absorb the water, the wool keep it's ability to retain air between the fibers. In polyester, the fibre does not absorb the water, and the space between the fibers is instead filled with water. Which results in total loss of insulating capability.

However if you completely soak a wool garment in water, it to loses its insulation, as the air pockts between fibers are filled. Which is why my grandfaters boat crew beat the water out of their soaked wool felt mittens. This allowed the wool to regain it's insulating power by replacing the water filled space between fibers with air, thus regaining the wools insulating capability.

You may try to soak a wool shirt and an equal cotton shirt. Then wring as much water as you can out of each. Which one do you think has the most loft after wringing? Wool or cotton?

 

[Bumbler]

ha !

I see that this isn't the first time then. well you know what they say, do your research !

Also has anyone any experience with unspun cotton ?

Just take a cotton ball, soak it in water...it collapses as the fibers stick together, losing most or all insulating capabillity. Sueze as much water out as you can, and it still sticks together in a tight lump.

Now do the same with some wool, and you'll discover that after squeezing as much water out as you can, it still has most of it's loft...thus insulating capabilty retained.

 

[petrochemicals]

Just take a cotton ball, soak it in water...it collapses as the fibers stick together, losing most or all insulating capabillity. Sueze as much water out as you can, and it still sticks together in a tight lump.

Now do the same with some wool, and you'll discover that after squeezing as much water out as you can, it still has most of it's loft...thus insulating capabilty retained.

the great wool war 4 (5? 6?) armistice declaration . 23.58 on the 14th of may 2013. The wool war to end all wool wars.

Does raw cotton collapse like down, is it heavy, and is it a good insulator ? Just a thought really.

Sheep to treat their wool though, lanolindoes keep some of the water out.

Ahem ,,,,,,,,,

 

[santaman2000]

I've got tweed clothing I've been wearing for well over thirty five years; when it wears out, (not in my lifetime!), it'll be re-processed and come back as still natural blanket, floor covering etc.

Maybe so. but are we only talking about clothing? I can reload a plastic shotgun shell many more times than an an older paper one. And synthetic cordage (particularly Kevlar) lasts far, far, far longer than cotton or hemp.

 

[santaman2000]

Do what?
Most of the synthetics I have used have died well before my natural s are showing any real wear!

In WWII the cotton webbing rotted away within a year (2 at most) The modern nylon webbing gets re-issued to new troops for decades (basicly until the design is obsolete and it gets sold on as surplus)

Also see previous post just above this one.

 

[santaman2000]

Wet wool is not the same as water. Wools insulation capability is retained because of it's ability to trap air in the fabric while wet. And it is the trapped air that keeps you warm....., provided your body is capable of heating it up. Cotton for example, loses this capability when wet. Same with down, which simply collapses, and with it's loft gone, it .

Ummm. The point is that if it's well and trully wet, there is no trapped air. The water's displaced it. And wool (like cotton) is a sponge; it soaks up water.