Double-Layer Ventile...and then some.

[bushtuckerman]

I just had a thought (clunk clunk clunk!), about the use of a double layer of ventile in clothing, i may be going over old ground here, but if the reason two-layer ventile is not totally waterproof over longer periods is due to the absorbtion of water from the outside layer to the inside layer, then should it not be pretty simple to stop that?

I mean, waterproof membranes aren't completely necessary if instead you just put a thick mesh loosely knit (and light!) with large-ish holes, so that it held the two layers apart. This could be more lightweight than adding a heavy insulative layer like thin fleece, but i am aware that it would only make for colder weather since it would be a fair bit heavier.

Maybe an idea for clothing manufacturers? I am no expert after all, so i would not be surprised if this were an unworkable idea.

-ian

 

[addyb]

Bushtuckerman,

No Ventile is totally waterproof. It's cotton, it eventually soaks through, even if it takes a good few hours. Single layer Ventile fabric is resistant to a 700mm column of water. A fabric must meet a bare minimum of 1000mm resistance to be classified as waterproof. Gore-Tex and the like have a hydrostatic resistance of 5000mm or greater; some up to 10,000mm water resistance.

The purpose of double-layer is for when the outer fabric "wets out" and swells. The inner layer simply stops the wet outer layer from sitting on your body. Ventile liner fabrics are a lighter, tighter woven material, resistant to about 900mm. West Winds sells a jacket model called "Cairngorm" which uses a loose mesh on the inner, instead of a liner fabric. I would say that it would not be much more effective than a liner, however.

This is why single layer Ventile is less water resistant than double; there is no liner fabric to stop the wet, swollen fabric from sitting next to your body. I have a double layer anorak, and I can honestly say that the only places I have ever had water soak through to the liner are on the shoulder seams, as Ventile is not seam sealed like Gore-Tex. Even so, after a few hours in the rain, the water spots on the inside of the fabric are no bigger than a dollar coin.

However, if one were to wear Ventile for say, 8 hours in heavy rain, even the inner will be completely soaked through. This is why it classifed as a "weatherproof" Only fabrics that are 100% waterproof will stop moisture from entering the inner of a garment.

I hope that helps. Just keep in mind that although Ventile may not be as waterproof as Gore-Tex, it IS quite showerproof, and has far more benefits to the user than Gore-Tex ever will. Different tools for different jobs. Would a person drive their Bentley along a 4x4 track?

Cheers,

Adam

 

[bushtuckerman]

addyb,

Thanks for the reply, you clearly know a lot more about ventile than i do, and you've helped me to understand the specifics, i agree with everything you have explained. I'm not sure whether you are saying these facts would make the idea i attempted to put across impossible or not, though. I realise that maybe there would be little use for such a combination of materials, i was merely excited by the prospect of (near) waterproof ventile clothing which would not in any way inhibit breathability.

I understood that ventile was not waterproof, i also undertsood that (maybe incorrectly) when ventile is saturated and swollen no more water passes through of it's own accord (of course if there is a layer to draw it through on the inner side then this is inevitable due to the strength of the hydrogen bond!), and this is why i have been thinking about it as a scientific problem.

I'll try and be clearer about what i meant. Like you say some jackets have an inner mesh material to aid them in some way. Is this for the fabled 'wicking' action or is this to aid water resistance? If these meshes are indeed for wicking then it is understandable why they transmit water through to an insulating layer after enough time.

What i am getting at is the fact that an inner layer of ventile, though perhaps more water resistant, does, like you say, absorb water eventually (but as you say not necessarily to a worrying degree). So, why not seperate these layers with a water-hating material, that does not 'wick'? As I understand it your answer to that is that no such material exists, i guess what i am talking about is thinking about the possibilty of making one, if the idea is as simple as i make out and undertsand it to be. I imagined that you could start by experimenting with a net, say, of a plastic such as fishing line, simply to test the idea, and see whether it could do the job of successfully keeping the inner and outer layers seperate during heavy use. Then, if successful attempt to use a more suitable material which had similar properties.

One might ask why i suggest having two layers of ventile and not: outer ventile layer - weird mesh idea - inner (of any breathable material such as straight off the loom cotton). And my answer to that would be that i am obsessive about ventile, and would want to put it everywhere! But i guess also it would then be a material as durable as the outer so could last a comparable amount of time.

I have a habit of being long-winded about things so i hope this doesn't drag...I'm sure it does!

-ian

 

[bushtuckerman]

I've seen your orange jacket in previous threads, it's Awesome

 

[addyb]

Ian,

Sorry I couldn't reply to this again sooner, I'm going nuts with my classes, and I have a midterm for psychology next week!

Anyway, here's my thoughts on your Ventile idea, plus some facts of my own.

Personally, I think that wicking mesh instead of an inner layer of Ventile is absurd, and possibly even a marketing ploy. You're quite right when you say that an inner layer of fabric aids in water resistance, but that it will get wet eventually. This is true, but it's not really much of a worry. I have WPB jacket made from a material called Entrant GII-XT, which is a polyurethane Gore-Tex type material. What's interesting about it is that the inner of the jacket is made of a wicking mesh, probably quite similar to what West Winds uses in it's "Cairngorm" jacket. I have found that this wicking mesh does little or nothing at all; it is no more effective than a three-layer Gore-Tex material. Double layer Ventile jackets are heavier and warmer than single layer, and they don't compact down quite as well as single. That is probably why some are willing to sacrifice some water resistance in favour of weight.

Your idea of putting a "water-hating" material as opposed to a wicking mesh is an incredible idea! And it's an impossibility, sadly. Why? Because cotton is cotton. Theoretically, you would need to use a solid, porous waterproof breathable material, such as PU as used in Entrant, or PTFE as used in Gore-Tex. But herein lies the problem: Those plastic coatings are laminated to a synthetic face fabric, either polyester or nylon. Unfortunately, you cannot laminate plastic to cotton.

The sole reason Ventile is so breathable is because it is cotton, nothing on earth is that breathable. (Remember, we're talking Second World War technology here). Modern day laminates and coatings are quite breathable, but sadly, not even as close as cotton. The trade off with breathability is a loss of water resistance. Ventile is, I would say, directly in the middle of all categories. It balances out breathability, wind resistance, water resistance, and durability. There are other fabrics out there that are much better in some of those categories, but not on that same equal scale. You have a magnificent idea, I've thought along those lines myself. If you want to stay as dry as possible in Ventile, all you have to do is layer yourself properly. A good thermal layer of wool, fleece, or fibre-pile, and a decent baselayer. (Hard to improve upon perfection, ya know!)

And don't worry, I'm obsessive about outdoor gear too. I can't believe I just wrote all this, I'm such a gear-junkie! Why fix what isn't broken?

Cheers,

Adam

 

[bushtuckerman]

No worries mate, my stress is relieved somewhat by having finished progress exams! Good luck with the midterm

Your idea of putting a "water-hating" material as opposed to a wicking mesh is an incredible idea! And it's an impossibility, sadly. Why? Because cotton is cotton. Theoretically, you would need to use a solid, porous waterproof breathable material, such as PU as used in Entrant, or PTFE as used in Gore-Tex. But herein lies the problem: Those plastic coatings are laminated to a synthetic face fabric, either polyester or nylon. Unfortunately, you cannot laminate plastic to cotton.

As i said i'm merely viewing this as a bio-scientific problem so point taken about not fixing what isn't broken, i would be perfectly happy with double layer for winter and single for summer personally. And i've had people tell me that wearing wool under ventile keeps you toasty dry anyway .

Not to wear this too thin but i think i should just say that i used the word material a bit too liberally, what i meant was netting (not fine mesh, wicking or otherwise), which would serve only the purpose of spacing the two layers, and nothing more, i don't think bonding anything together would help much with this idea. I agree with you, there are no current materials/fabrics which are completely breathable and water resistant/proof at the same time, and there is little point looking for one.

But just to hypothesise with this idea, if you took an extreme and supposed that you had a netting with threads (of nylon maybe) which were very (stupidly) large, say a centimetre in diameter and put either side of it a layer of ventile, and put the whole lot at an angle and continuously pured water over it, then the outer layer would swell, and some water might drip down the inside i guess, but i don't see how this water could make it's way to the other ventile layer, since there is no absorbtive pressure/force to draw the water across, and even if it did it would have room to vapourize from body heat (using not too dissimilar mechanics to pertex/pile fabrics), and this would still be, to all intents and purposes, breathable. Of course, the other extreme is the useless mesh you find in some jackets. So, if i were to experiement with this i would aim to find the happy medium, which i think would prolong the completely dry liner hours you get out of your jacket, when it's tipping it down. The downside is, as usual, weight, which any person in their right mind could deem unnecessary when you already have the added weight of the water on the outside layer.

Maybe absolutely anything you might put in the middle would draw water across for other reasons, but really what i am trying to imagine is how you might cheat the mechanics of a canvas tent which has the two layers seperated, but both are wet when it's raining (and i seem to remember that you musn't touch the inside layer when it's wet!).

I think you already get what i am saying and have accepted that it just would not work! but i wanted to be clearer anyway.

Hopefully i will get a ventile smock soon, but i haven't found a double-layered one which i would find ideal, the extra weight doesn't bother me too much, especially not if it's winter, i can always wear my light nylon berghaus (PU coated!) jacket if i need to for showers in the summer, which virtually fits in my back pocket.

Thanks for your patience! it's another long one

-ian

 

[addyb]

Ian,

That's a really good point about angles and water shedding. If a canvas tent is set at somewhat severe angle, as long as you don't touch it, there's no way for water absorbtion to occur. It's just like I've said numerous times before, my anorak only soaks through along the shoulders and hood, because those parts of our bodies are rather flat and almost horizontal.

What if you designed some sort of parka with semi-ridged shoulders and hood, with the two layers seperated? That way, you'd have an angle that water would roll off of, and it wouldn't absorb through to the other side. Like, think of a football (American football, not "footy" soccer like you Brits have) player's shoulder pads. Do you think that would work, say, in a much smaller, lighter form? If you built that principle into a parka, you'd definately find some interested customers! And also, by somewhat seperating the layers, you'd have a dead-air space for warmth.

Something tells me that you're a chemistry major!

Damn, this a good theoretical topic!

Adam

 

[bushtuckerman]

it's an idea, but wouldn't you just look like one of the cast from star trek? I have no idea whether any of these ideas would work in practice, obviously, but in my book anything is worth a try if you enjoy experimenting. I guess it would help with water shedding, but i think you would end up with a coat only suitable for Spock if we are thinking in commercial terms!

The dead air space part of this is well raised, it's why i was thinking it would be better suited to the winter.

I don't know about designing a jacket, i'm just toying with the idea really! But i'd love to have the chance to experiment with it.

Oh i'm not that good at chemistry but i have to study it for the first year of my degree.

-ian

 

[bushtuckerman]

In terms of shoulders etc, i guess that is combatted fairly well by not putting seems there and perhaps using two or three layers in those areas.

 

[mark a.]

It's a great idea, and I've been giving it some thought, but I'm not sure it'll work. Even if your "string vest" was hydrophobic e.g. plastic, it would still transport the water fairly well I think (due to surface energy etc) around the fibre/string onto the second ventile layer.

That's sounding fairly negative, which I must admit isn't really fair as no-one really knows the answer. You may have hit on something really simple and obvious so that when you've patented the idea and made your millions everyone else can go "I wish I'd thought of that - it's so simple!"

Perhaps the moisture transport process is fairly inefficient with the middle layer, so the inner layer does remain drier for longer. I suppose a couple of squares of ventile, some water and a selection of intermediary layers would help us find out.

 

[addyb]

That's true, it could very well be a great idea!

Another possibility that Ian could use would be to put multiple fabric layers in flat, non shedding areas of a garment. For instance, my anorak has a 4-layer chest pocket. The rest of the jacket is double layer. (Don't ask why!)

As well, putting the seams different location could also work. Because my anorak is 1970's Vintage, the shoulder seams are directly horizontal. And seeing as Ventile cannot be seam sealed, this is probably why I get dollar coin sized water spots on the shoulders. I understand that with modern anoraks, the shoulder seams are sometimes put in different locations, so that water cannot creep in quite so easily.

Ian, work on it, patent it, and make million bucks!

Cheers,

Adam

 

[bushtuckerman]

Ok, so this idea, which henceforth will be known as 'string vest' theory courtesy of mark a., might be worth some testing. If i get hold of some ventile somehow then i could give it a shot. I think i've got to own a ventile jacket before i can realistically evaluate it, so it'll be a while but i'm patient! I'm not sure about making millions, i am severly lacking in business acumen, but i wouldn't mind trying to make my own coat with a little help from a seamstress!

It's a valid point mark, and far from negative, that is precisely where my doubts lie too:

Maybe absolutely anything you might put in the middle would draw water across for other reasons

That's pretty much what i meant but was not sure how to express it, but you said it, 'surface energy'! My conclusion was that if it worked then it would be because there was not enough kinetic energy involved for it to affect the inner layer too much despite whatever surface energy there was, at least, not the kinetic energy rain has etc, and it would still be drawn across at a lower rate, so maybe if this were offset/lagged enough then body heat could cope with it, and either way the coat is likely to be warmer with all the extra still air.

I have been quite relaxed about how breathable a coat would remain, but i don't actually know how that would be affected, maybe someone with more experience with ventile might have an idea, hopefully it would not be made less so.

The idea, if valid, i think is simple, but maybe production will become progressively more complicated as you work from problem to problem through this process.

Has the pertex/pile system been tried with ventile? I don't know the comparitive features of the two materials, as i have used neither.

I think if you imagine a plastic like nylon then it's easy to see that water might travel over it quite quickly, for when you hold fishing line for example, it is shiny and reminds you of glass, and we all know that water sticks to glass, and if i remember correctly this is due to weak van der vaals forces (how spiders stay on ceilings - not your joe bloggs chemical bond). Maybe in bettering this as a future project one might come up with less electrostatic material that didn't have so much surface energy at it's disposal, if that makes sense, i'm not sure it does though. Basically so that it felt less inclined to get you wet! I think a rough, instead of glassy, surface would help.

Anyway, i'll carry on thinking about it. any comments welcome! and maybe if someone has some offcuts they could have an experiement or two.

Thanks for the ideas and encouragement!

-ian

 

[addyb]

haha wow, this thread seems to have taken on epic scientific proportions!

A bit of advice for you, Ian: If you get a Ventile jacket, treasure it. They're far too expensive for us poor, cash strapped university students to be cutting up for experimentation. I'd never be able to afford one, but I was lucky enough that an old climber gave me one. And I might be getting another one too if I play my cards right.

And Pertex/Pile I'm not a big fan of. I had a soft-shell jacket once, it was microfleece laminated through a membrane to a polyester microfiber shell, very similar to Pertex/Pile. And my conclusions:

a) It dries a helluva lot faster than Ventile. (obviously)

b) It's not even close to being as weatherproof as high-performance cottons.

c) You CAN get fleece-backed ventile from Snowsled. It dries faster than dual-layer, but isn't quite as weatherproof.

And that's it, I've got nothing else to say. I think that this thread will go down in history as "the most technologically informative Ventile thread in the history of the world."

Adam

 

[bushtuckerman]

Lol!

Oooh, don't worry i would most definately not be cutting up good bits of kit which i know work just for the sake of experiment! it's a funny idea but also nearing sacrilege

If i get a ventile jacket though i would be in a better position to judge messing about with offcuts or something similar.

Yeah i know the feeling! Still, loan wise it's the cheapest money i'll ever borrow.

I forgot about the snowlsed fleece lined jackets, i guess they might be a kind of half way house.

thanks again

-ian

 

[Wink]

Why can't Ventile be used with a "directional" type pump liner, such as the Paramo Analogy Pump Liner? As I understand it, Paramo gear works on the principle of the outer (in their case synthetic) being weatherproof but not waterproof. Any moisture that gets through can't get through the second layer, because it wicks, but only one way - outwards, mimicking the action of animal fur. Accordingly, in driving rain, the outside wets out, but the inside is dry. Any water that finds it's way in (eg down the back of your neck, or through perspiration) is immediately wicked away from the body by the pump liner, presumably to be evaporated away as soon as there is a break in the weather!

Paramo gear seems to work, as can been seen by its success in this year's Trail Magazine customer satisfaction survey, where it came top in two out of three categories for waterproofs, despite the magazine itself always banging on about more conventional gore-type jackets. If the same principle was applied to a Ventile jacket, surely it should work... or am I missing something? There should be no loss of breathability, because the pump liner has no membrane, but you should also be able to get away with just one layer of Ventile, saving weight.

I deliberated long and hard about getting a Ventile jacket, but decided against in the end because it was hugely expensive and I couldn't be sure that I would be dry. Imagine multi-day trips where it rained all the first day... In the end I bought a Keela Munro jacket, which has two waterproof layers with an air gap, but is nowhere near as breathable as Ventile due to having two membranes. I have to make do with pit zips! I also have to be careful with sparks etc, as it's synthetic. Sigh.

Somebody handy, could you please knock up a single layer Ventile with a Paramo membrane and report back? Ta.

 

[leon-1]

I had a thought on this that would keep you using natural materials, it would mean three layers over the shoulders, but it may be possible to use a thin layer of felt.

Felt will retain water, it is water resistant, it is insulative and it will absorb impact and provide cushioning against the straps from a bergan or heavy pack.

If it was to be laminated between two layers of ventile it could be quite effective, after all felt has been used for insoles, hats, boots and even skirts so why not a breathable resistant layer between two layers of breathable water and wind resistant Ventile.

Toddy would probably be able to give more advice on this, since she has more knowledge than I on the textiles side of life, but it is an idea.

 

[Graham O]

As I new subscriber, I was interested to read this thread on spaced fabrics particularly using Ventile. This was something we tried about 10 years ago with some success. The two layers were separated by a special mesh about 5mm thick and this did everything we wanted it to. It provided the separation to prevent migration of water across the air gap, fabrics dried out quicker and comfort was increased. We even tried this with just showerproof fabrics and found that 2 layers were nearly as waterproof as a coated fabric.
Using Ventile, we got a really good system, but double Ventile was overkill. The inner layer was too much and we could get away with much cheaper fabrics.
We even tried garments with very waterproof but non breathable outer fabrics, such as neoprene coated nylon. Condensation occurs on the surface of the outer fabric as it is colder, so if this surface was spaced away from the wearer, the condensation would be "removed" from the wearer. Put a showerproof, but very breathable fabric as an inner layer, then the spacer and the neoprene nylon on the outside. Sweat could pass into the air gap where it would then condense on the neoprene and by leaving the hem of the jacket open, it could then drip out and dry out.
If it was so great, why didn't it go into production? It was too bulky, too expensive and too warm.

Hope that helps!

Graham

 

[addyb]

Graham, how do you know all this, do you work for Talbot Weaving?

Anyway, Snowsled makes single layer Ventile with fleece backing it. I imagine that this would function similar to pertex/pile, but I do believe that Ventile is more showerproof, albeit much slower to dry. For a time, I had a softshell jacket, basically pertex/ple with a zip front and pockets. Although it was DWR coated, it wasn't near as weatherproof as my Ventile anorak. It DID however, dry much faster when soaked than the anorak. I made the mistake once of after a good soaking to leave my anorak hanging up in my garage which adjoins my house. In the morning, it was still sopping wet and quite stiff. Ever since then I hang the Ventile up inside. I have also found that wet Ventile dries fairly quickly if one continues to wear it when it is saturated.

As to single/double layer....I really don't mind double layer. I wouldn't trust single layer Ventile fabric in terms of showerproofing. As a lightweight windtop, gawd yes, I would KILL to have one. I look at it this way: My double layer anorak isn't really much heavier or bulkier than my Entrant GII-XT jacket. It's softer, more comfortable to wear, and encompasses a much wider range of conditions in which it can be worn. It's only drawback is that it gets a bit damp after oh, lets, see....3 or 4 hours in the rain? Well so what, I don't much like the rain, and when I layer myself properly I'm probably drier from the rain in my 30 year old Ventile than I would be from the condensation that wouldn't escape my Entrant jacket.

It's not perfect stuff, but I have a pretty good feeling that Ventile isn't something that's going to be improved upon anytime soon. It was perfect back in World War Two, and it's still perfect today!

Cheers,

Adam

 

[bushtuckerman]

Graham O,

I was amazed when you said you tried the idea of getting water to condense and leave at the hem, it was something i thought about, but assumed would be too bulky as you say.

They are all going to be bulky, whatever you use, so would all be winter systems. Maybe someone in the space industry could lend us some aero gel ...no, seriously

5mm is what i imagined would be a maximum thickness, any more and bulk really does play too large a part.

Were/are you in the clothing industry when you use the word 'we'?

It's worth bearing in mind that as soon as any ventile system you can come up with ceases to be as breathable it becomes pointless, but we all know this. It's also worth noting that when wet, ventile is always going to be less, if at all, breathable.

I think what this thread is about now is exploring all the possibilites, obviously i hadn't realised this had been done before and am pretty excited that it has. You ended the post in such a way that suggested there would be little point in persuing the problem, but i think it's worth it, scientists always encounter the most obvious problems first in this way, and don't give in at that point because thay know persistence has worked in the past. This is not a criticism however, and i am very grateful for your post, it helps jump a few stages with the idea.

As far as cost goes...well commercially it would require a very specific target group, so would always encounter cost problems, but how many people on here have made their own? The felt idea is a good starting point for experiments i think, i like the idea that you could use a natural material. Toddy, do you have any ideas about this?

@Wink,

Hmm, well why not? i have no experience with paramo gear so i can't comment directly, but i guess the question is why haven't they? maybe because they (paramo) wanted a lighter weight system, or maybe because they are just two different principles which when together don't like each other. It's most likely cost though.


This is not directly related, but i just bought second hand a survival aids parka. It was advertised by the seller as double layer ventile...it quite simply is not. It has two layers behind some pockets, but not where you need it on the shoulders, this is disappointing, but i like the design so much i think i'll keep it anyway. He may also have washed it with something as there is a soapy residue in areas and the taped seams (although some say unnecessary) sound like they have unstuck (i.e. washed at 40). It has two layers though, one ventile, one plain cotton, this makes it really nice and warm to wear, but not entirely reliable weatherproof wise, as i suspect this inner layer will wick water towards me and draw it through the outer layer! I hope to get away with wearing wool underneath, and when it gets really cr*ppy outside stick a poncho on. But it's not about staying dry right? it's about staying warm, and staying warm when you have stopped doing work and the inside of your jacket is or is (hopefully) not drenched with sweat...

cheers people

p.s. just reading up on aerogel and it turns out it could be effective! it is highly hygroscopic, which means that it absorbs water readily, and you can also treat it to make it hydrophobic. So if you just treated it on the side of the outer layer and left it how it was on the inside layer it could work, but it would be incredibly warm as it insulates very well, and would probably shatter, but nevermind...

 

[Graham O]

My knowledge of Ventile has come from working with it for quite a few years.

We tried the spaced fabrics due to a request from an end user who had very specific needs, very different from most "normal" users. For the spacing, we had a polypropylene mesh woven with different properties and spacing. It was completely air permeable and non wicking. We even had one which could be put in the knees and it was strong enough to take a persons weight without crushing, i.e. no more wet knees if kneeling in a puddle! We had such fun, lying in puddles and streams! However, I don't remember the failure products being such fun.

To cover some of the points raised:
With regards cost, being highly specialised, the garments (jackets, trousers and salopettes) would have been over £400 for a jacket and even well funded organisations had to think twice at that point.
Ventile works very well and although spacing is an option, a non air permeable fabric such as a felt or a woven or non woven fabric, will introduce its own properties which generally, will detract from those of Ventile.
Ventile Pile is quite an interesting combination, but it can be very warm. Ventile on its own is cool when hot and warm when cool, but add the pile lining and it heats up. We have some garments going out to Alaska soon to be tested at -50F so will keep anyone who is interested informed. For a time Snowsled replaced all their double Ventile clothing with Ventile/Fleece. They claimed that the fleece enhanced wicking, as it should do, but I think it was predominantly for cost grounds. I notice that double Ventile is back on the menu now.
I've tried many different Ventile garments in the 3 main grades and with different seam techniques. I wasn't able to find any difference between the L19, L24 or L34, but the seams made a big difference to the manufacturing process. For the end user, it was less important. Some fairly simple designs, but strict quality control give seams which work as well as the more complex ones and give a better finish.

If anyone wants to know more, feel free to ask.