Does Merino Wool Wick?

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Dan00001

Nomad
Nov 13, 2023
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I've been reading this book 'Keeping Dry & Staying Warm', authors of which include Mike Parsons of Karrimor, Chris Townsend, Author and ambassador of the BMC and Alan Hinkes OBE. Altogether there are some pretty experienced outdoors people who have contributed to this book. Anyway, the book states that Merino wool is non wicking.

"Merino wool is very often used for base layers. But it does not wick; instead it absorbs 60 per cent of it's own weight in water. However, the garment still feels good because the outer surface of the wool remains dry. It is often claimed that it is antibacterial, but that is not correct. Wool just takes more time for the bacteria to build up because of the dry surface. Because wool lacks wicking capability (it can't possibly wick because it retains a dry surface), it is often mixed with polyester (which will be used on the outside of the garment)."

I think this is the first time that I have ever read somebody say that wool is non wicking. I'm not saying this article is right or wrong but interested in peoples opinion on this and whether others have heard this before or not?
 
No, it doesn't wick. It's hair, it's meant to A) shed the rain and B) let it dry off as the hair blows about in the wind.

Thing is though; even sodden wet, so long as you stop the windchill (and felted wool does that to a very good effect) it'll still keep you warm....unlike cotton which clings like a cold wet shroud :sigh:

Wet wool's heavy though.
 
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No, it doesn't wick. It's hair, it's meant to A) shed the rain and B) let it dry off as the hair blows about in the wind.

Thing is though; even sodden wet, so long as you stop the windchill (and felted wool does that to a very good effect) it'll still keep you warm....unlike cotton which clings like a cold wet shroud :sigh:

Wet wool's heavy though.
Yes, pretty much what it says in the book, wool will still retain it's insulating properties even when wet.

Thanks.
 
Merino wool does have some wicking properties compared with other wool textiles but not as good as a number of man-made fabrics. All materials are a compromise to some extent though.

This table was published following independent research (i.e. not a clothing or fabric manufacturer but, sorry, I've lost the source) - one can argue with the detail based on one's own experience, but it's a reasonable comparison table.
 

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Merino will not feel cold and damp worn directly against the skin when wet. Unlike cotton.
And last summer I had a mesh polyester undershirt and on top a merino t-shirt.
I did not feel at all wet though bicycling in decent rain and t-shirt was soaking wet.
 
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Merino will not feel cold and damp worn directly against the skin when wet. Unlike cotton.
And last summer I had a mesh polyester undershirt and on top a merino t-shirt.
I did not feel at all wet though bicycling in decent rain and t-shirt was soaking wet.
Merino isn't magic, it can definitely feel very damp when directly against the skin, it just depends heavily on the conditions and also the garment. I say this having been caught in some extraordinarily heavy rain, 55mph gusts, and my trousers wetting out and my merino leggings (I think 180gsm) very much telling me about how much water they were holding.

I was warm, but they felt very wet indeed, and they were!

But I wouldn't change them for any others, because at least in my experience of synthetics, these are what work best for me in the vast majority of conditions.
 
On your OP @Dan00001 I have always wondered what is meant by 'wicking', isn't it just the movement of water/liquids from one place to another by capillary action? As such, lots of clothing fibres do this and merino does certainly, but it's the manufacturers adding to what's meant by 'wicking' which makes things a bit more tricky. Is that the addition of 'transporting a liquid from one side of a material to the other and forcing its evaporation' or suchlike?
 
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I get the impression that when used in advertising “wicking” implies a one way movement, usually of perspiration.
Whether it would in any way impede water from the other direction I have no idea but doubt.
I have never taken “wicking” into consideration when buying clothing.

Do merino woollen garments absorb moisture - yes.
Do they control the flow in any way - I doubt it.
Do they keep you warm when evaporation might cool you - a bit.

(In my limited experience of merino base layers.)
 
On your OP @Dan00001 I have always wondered what is meant by 'wicking', isn't it just the movement of water/liquids from one place to another by capillary action? As such, lots of clothing fibres do this and merino does certainly, but it's the manufacturers adding to what's meant by 'wicking' which makes things a bit more tricky. Is that the addition of 'transporting a liquid from one side of a material to the other and forcing its evaporation' or suchlike?
Yes, here is an infographic and definition from the book on wicking. I don't know if what they mean is that Merino wool doesn't move moisture from one outside surface, the surface against your skin, to the opposite outside surface, the surface not against your skin?

The book isn't in any way saying that Merino is bad, in fact Chris Townsend uses Merino base layers.

 
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I get the impression that when used in advertising “wicking” implies a one way movement, usually of perspiration.
Whether it would in any way impede water from the other direction I have no idea but doubt.
I have never taken “wicking” into consideration when buying clothing.

Do merino woollen garments absorb moisture - yes.
Do they control the flow in any way - I doubt it.
Do they keep you warm when evaporation might cool you - a bit.

(In my limited experience of merino base layers.)
There is actually two types of wicking textile, basic and directional. Basic being the majority of wicking textiles, will wick in both directions. Directional wicking textiles only wick in one direction. I believe there are only a few companies who use directional wicking textiles in outer garments, Paramo, and the two companies who licence the technology from Paramo.

Polartec Power Dry and Power Stretch fabrics are apparently directional wicking and used in some base layers.
 
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Merino will not feel cold and damp worn directly against the skin when wet. Unlike cotton.
And last summer I had a mesh polyester undershirt and on top a merino t-shirt.
I did not feel at all wet though bicycling in decent rain and t-shirt was soaking wet.
I've been thinking about mesh base layers and have been wanting to try one. I understand the theory of trapping pockets of air but since reading this book I've been wondering how do they deal with moisture? do they reduce moisture vapour transmission rate and do they increase evaporative heat loss?
 
I've been thinking about mesh base layers and have been wanting to try one. I understand the theory of trapping pockets of air but since reading this book I've been wondering how do they deal with moisture? do they reduce moisture vapour transmission rate and do they increase evaporative heat loss?
I have a couple of mesh tops for under paddling kit. Seems to work well enough for me, though they stay hidden!! I decided to try it after listening to Andy Kirkpatrick. He has some very definite views.

I’ve just done a search and this probably summarises it but he probably waffled a lot more in his podcast where he mentions it and possibly has more info there as well.

 
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I have read a lot of various sopoirces about wicking and the majority of the more trusteed sources say wool either does not wick or has very poor wicking properties. AIUI there is surface physics and charge involved but I am so far out of my materials engineering degree to reemember all that stuff. IIRC synthetics and natural fibres have different surface charges which plays into this.

The best thing to accept is that what works for you works for you. If you want to go into it more then the techies seem to summarise it as wool keeps comfortable by absorbing moisture but synthetics do it by moving water away from your skin, some directional wicking which is not jsut the paramo analogy but there are other fabrics doing it to. They are called denier gradient fabrics IIRC and work by dense and more open faces within the weave. Para,o aree not the only proponents of this known tech. There is also a degrree of graadient flow probably going on. Hotter against the skin, colder against the outer face and more moisturee near the skin less on the outer. All helps to move it away from the skin.

Then the surface chemistry and physics comes into play. Out of the synthetics not all are equal with polyesteer and nylon actually not being that great at wicking. I think that is why the table posted upthread has them. If they had put polypropylene in there it would have skewed the wicking rating heavily the wrong way for all fabrics.

I have never got on with wool on its own. I have had both cheap and expensive and they have all holed out at wear points. I have however had HH prowool tops and they aree wonderful winter basse layers. Unlike alot of wool and synth combined which have the syth on the outer layer HH have PP on thee inside and wool on the outside. FOr me this worked very well. PP kept myy back dry and what could not be wicked away fully was absorbed by the wool outside of the PP inner. I often ovewrwhelmed the wool's ability to remove moisture when walking in winter but the PP kept the moisture in the wool outside of the imner PP face.

However I have felt many times with pure merino base layers the feel of wetness on the skin due to sweating. I do belive in mathcing effort and warmth needs with lahyers worn to prevent overheating, but at times it is not feasible to change layers as needed and you have to rely on coping with wet and warm. Wool will do that as will synth for me but HH prowoll with PP inner and wool outer works so much better for that situation IME.

This is all academic. It matters not if wool wicks or doesn't. It matters whether you are comfortable with what you use. If it works for you then that is good enough I suppose. Could there be better? I do think there is better than pure merino but do you need it if good enough is enouigh and you have confidence int it?

So conclusion is, IMHO, wool does not wick that well, PP does (about 300x more hydrophobic and hence wicking than nylon which is about 4 or 5 times or more wicking than wooll. However I do not care about that. I only caree about what I choose to use works for me. I think others should think more llike that. Finite answers on all this won't get you any further but finding that kit that works for you willl.

PS Townsend and Parsons know what they are tallking about with outdoor kit. If they say wool does not wick then consider it to hold some truth.
 
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@Paul_B do you know what the HH (presumably Helly Hansen) material was called? I've had a look at their website but they have so many material names with merino but I couldn't find many with polypropylene. LIFA maybe?
 
LIFA is pp but weirdly their merino is 2 layer merino and pp. They've dropped the prowool tag. Mind you when I got mine they had a totally different name again for the fabric. That's how long it's lasted.

BTW HH PP LIFA base layers last forever. They'll be digging them up still attached to a keen hiker 1000 years from now! If it wasn't a bit wrong you could pass them down the generations for those 1000 years as well! Mine are about 40 years old without any holes in or signs of wear. Meanwhile the longest my pure merino tops have ever lasted is 2 years, actually that's 2 winter seasons so not even 2 years of use.

Of course you might get them and find out they're rubbish for you. That's the vagaries of human opinion over outdoor gear. One man's go to is another man's reject kit.

One last point. After worn for a few trips, HH LIFA tops all start to smell the same, badly! They tend to make BO linger a bit. Have you not heard of smelly Helly?
 
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I have a couple of mesh tops for under paddling kit. Seems to work well enough for me, though they stay hidden!! I decided to try it after listening to Andy Kirkpatrick. He has some very definite views.

I’ve just done a search and this probably summarises it but he probably waffled a lot more in his podcast where he mentions it and possibly has more info there as well.

Thank you, looks like there will be other interesting blogs and articles on his website that I can have a read of.
 
I have read a lot of various sopoirces about wicking and the majority of the more trusteed sources say wool either does not wick or has very poor wicking properties. AIUI there is surface physics and charge involved but I am so far out of my materials engineering degree to reemember all that stuff. IIRC synthetics and natural fibres have different surface charges which plays into this.

The best thing to accept is that what works for you works for you. If you want to go into it more then the techies seem to summarise it as wool keeps comfortable by absorbing moisture but synthetics do it by moving water away from your skin, some directional wicking which is not jsut the paramo analogy but there are other fabrics doing it to. They are called denier gradient fabrics IIRC and work by dense and more open faces within the weave. Para,o aree not the only proponents of this known tech. There is also a degrree of graadient flow probably going on. Hotter against the skin, colder against the outer face and more moisturee near the skin less on the outer. All helps to move it away from the skin.

Then the surface chemistry and physics comes into play. Out of the synthetics not all are equal with polyesteer and nylon actually not being that great at wicking. I think that is why the table posted upthread has them. If they had put polypropylene in there it would have skewed the wicking rating heavily the wrong way for all fabrics.

I have never got on with wool on its own. I have had both cheap and expensive and they have all holed out at wear points. I have however had HH prowool tops and they aree wonderful winter basse layers. Unlike alot of wool and synth combined which have the syth on the outer layer HH have PP on thee inside and wool on the outside. FOr me this worked very well. PP kept myy back dry and what could not be wicked away fully was absorbed by the wool outside of the PP inner. I often ovewrwhelmed the wool's ability to remove moisture when walking in winter but the PP kept the moisture in the wool outside of the imner PP face.

However I have felt many times with pure merino base layers the feel of wetness on the skin due to sweating. I do belive in mathcing effort and warmth needs with lahyers worn to prevent overheating, but at times it is not feasible to change layers as needed and you have to rely on coping with wet and warm. Wool will do that as will synth for me but HH prowoll with PP inner and wool outer works so much better for that situation IME.

This is all academic. It matters not if wool wicks or doesn't. It matters whether you are comfortable with what you use. If it works for you then that is good enough I suppose. Could there be better? I do think there is better than pure merino but do you need it if good enough is enouigh and you have confidence int it?

So conclusion is, IMHO, wool does not wick that well, PP does (about 300x more hydrophobic and hence wicking than nylon which is about 4 or 5 times or more wicking than wooll. However I do not care about that. I only caree about what I choose to use works for me. I think others should think more llike that. Finite answers on all this won't get you any further but finding that kit that works for you willl.

PS Townsend and Parsons know what they are tallking about with outdoor kit. If they say wool does not wick then consider it to hold some truth.
Brilliant information, thank you! Gives me more to read up on.
 
The thing I like about thick fibre pile (think Bison or old Helly Hansen) is that it drains really well, drys to an extent while wearing but doesn't feel cold. (based on offshore sailing & especially on my experience of falling into a cold winter river earlier this year). But needs really wind protection.
 

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