Double-Layer Ventile...and then some.

[bushtuckerman]

...we had a polypropylene mesh woven with different properties and spacing. It was completely air permeable and non wicking...

...a non air permeable fabric such as a felt or a woven or non woven fabric, will introduce its own properties...

...We have some garments going out to Alaska soon to be tested at -50F so will keep anyone who is interested informed.

Thanks Graham , really helpful information. I'd be very interested to know how the Alaska coat performs.

Do you mean that if it is air permeable it is also water vapour permeable and therefore allows faster moisture transfer? Because that seems to make sense.

Can you give any more detail on the mesh, for instance whether it could be improvised at home or whether it is particularly complex. I am quite keen to know how it works. Earlier in the thread it was suggested that the surface energy of the fibres could move water across the [relative] gap to the inner layer, is that not the case?

cheers

 

[leon-1]

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.

When you say non air permeable what exactly do you mean?

If you mean that both air and or vapour cannot pass through felt that is unlikely, if you do not believe me try blowing through a set of Lundhags insoles. If however you mean that like all woollen garments they are warm partially due to the hollow fibre that makes up wool and that it will trap a certain amount of air in air pockets then you are correct. Felt is however breathable.

Felt is as you say non woven relying on the way the woolen hair is made up to hold itself together, but as with any woolen garment it is warm even if soaked as with Dachstien mitts, but felt comes in many different grades including stuff that can be used in heavy machinery. Felt doesn't absorb water very well, however it does retain it if it gets soaked and it does have a wicking action taking liquid away from the body rather than drawing it into it which are some of the reasons that I suggested it.

 

[Graham O]

"try blowing through a set of Lundhags insoles" !!!

You are one sad individual!!

Only joking, so please don't take offence. But with the way my Lundhag insoles smell, putting them near my feet is quite close enough!

The concept behind the spaced Ventile was that in many ways, Ventile was the best all round fabric for our project requirements. What we wanted to do was increase its waterproofness and comfort without detracting from breathability and wearability, plus some other specific needs. A plain sheet of Ventile is great, but once it is punctured with stitch holes, or its properties are modified by pressure, i.e. kneeling on it in a puddle, its looses some of those properties. We tried to put wicking fabrics inside and yes, they would wick moisture away from the wearer, but in a static situation, they also tend to wick moisture which gets inside, around the wicking layer. In periods of inactivity, the body does not produce enough heat to pass it through the Ventile so there was a build up of moisture and hence loss of warmth and comfort.

With regards more details of the mesh, sorry, but that has to remain confidential. It was specially woven for this application and involved a lot of time and money.

With regards the felt, I agree with everything you say. However, as I say above, we did not want to detract from the properties of the Ventile and putting something which had very different properties would have reduced the Ventile's attractions. For example, if a fabric is 100% breathable and you put a non breathable next to it, the overall effect is 0% breathable. You've taken a 100% fabric and made it useless for the parameter you originally chose it for. We did not want to do that.

However, the one feature I've found in dealing with many different customers, has been that we are all different and it is important for the individual to find out what works for them. Most of our work was concerned with long periods of inactivity, while most people on this group, myself included, can not sit still for more than a few minutes. What worked for those customers may not work for us.

Wool has some really great properties and having got some cheap Merino wool tops from Lidl last year, I would love to try a Ventile/Wool garment. If I could get some, I wonder if anyone on the group would like to act as a tester? (he immediately takes cover expecting a flood of offers!)

Graham

 

[Buckshot]

I wonder if anyone on the group would like to act as a tester? (he immediately takes cover expecting a flood of offers!)

I think you could get a couple of thousand offers there !!!!!

So I'll be the first

Mark

 

[BorderReiver]

I would like to help.I run very hot and sweat like a pig even with moderate exercise in low temperatures

 

[Graham O]

Border Reiver,

You paint a lovely picture!

 

[leon-1]

Hi Graham, thanks for the concise answer, it would be an impossibility for me to blow through the set of lunhags insoles that I use in my moccasyns as they make up the mid sole laminated between two peices of leather.

I have a set that are brand new that I had no need to use as one of the members here sent me some carded wool to felt (thank you Toddy you're a star ).

There are a couple of people that use a combination of wool and Ventile that I know of on BCUK, Neil1 and who was the other, oh, that's right me .

It is very much a bombproof combination. Neil1 has a tendancy to make a lot of his own kit and I am lucky enough to know him well enough that sometimes I benefit from his hard work.

I know an amount about being static in cold conditions and know of the problems that you will be looking at very well indeed. I have used one peice suits designed by DuPont for extreme cold and quilted suits with a goretex outer which are supposed to have similair qualities to a sleeping bag. Both of these being used for laying static in one location for prolonged periods of time, as you say compression is one of the major problems.

Another is if the suit springs a leak when you are laying in a damp area and can't go anywhere to change the now damp and cold inner clothing you are wearing, although if you are lucky it can sometimes work like a wet suit with a layer of water warming against the body, the major problem with this as you know being that it will sap the heat from your body cooling you faster.

 

[BorderReiver]

Border Reiver,

You paint a lovely picture!

Sorry about that.

Just telling it like it is.

 

[addyb]

Okay, I'm way off topic here, but I'm going to ask Graham this one last question:

The only place that I've ever had my Ventile "leak" (wet out) is on top of the shoulders and the hood. This is where the seam is placed. If I was wearing a pack, it would be even worse, as the strap pressure would force even more water through. It does help when I wear my Helly Hansen Fibre Pile jacket underneath, and a Lifa or Malden Mills base layer underneath. At least that way, my body heat keeps the water pushing outwards.

Unfortunately, after a good couple of hours in heavy British Columbia rain (they don't call it the Wet Coast for nothing!) the shoulders and hood become quite damp. This is because the two layer touch each other and also because Ventile is cotton, and cannot be seam sealed like a WPB garment.

Is there anything that can be done with this? Like, it's funny, I've got a 30 year old jacket, completely showerproof, I've never been soaked in it, except for small spots of the shoulders and hood. Am I pretty much stuck with this? Is it the one detractor from Ventile?

Curious,

Adam

 

[Graham O]

Hi Adam,
I think that the head and shoulders will always be the areas to wet out as they are the only horizontal parts of the body. Water will typically run off the head, but being exposed to the rain, it quickly gets more water on. The neck seam is the biggest problem area as it is horizontal and under some strain from rucsac straps, turning of the head etc. Having tried a great many seam techniques, including ones which were technically good, but almost impossible to stitch, I think the trick is to keep the path for water into the garment as difficult as possible. I've tried French seams, lap and fell seams and simple plains seams topstitched upwards, I have not found a definitive "best seam". French seams would appear to be the best, but are the worst of all as the stitch holes are visible to the rain.
I don't know if it is true, but I read a long time ago that the tassles on a cowboys jacket, as was seen in 50's Westerns, were there to encourage the water to shed from the garment. If you can get rid of the water at the same rate as it is coming down, that has to be a good idea. I've often wondered about giving it a try, but I don't have the nerve to be seen out in such a garment!

I think that if you are just getting damp in the garment, rather than soaked, then it is probably a case of just accept it. If you want to stay completely dry, then synthetics are the way to go, but expect to replace garments much more often.

With regards the two layers touching each other, there will be some direct capillary action from one surface to the next. In a double layer garment, unlike slippery synthetics, the Ventile will largely stick together and appear as one layer. I've tried a single layer jacket for showerproofness with a big oversmock as the waterproof layer. The two garments are cut differently, so they tend to move differently and generate more of an air space between them. It is very subjective, but I've found this to be more weatherproof than a double layer garment.

Hope that helps.

Graham

 

[bushtuckerman]

Graham,

Have you tried, or indeed do you think it would work, to have ventile as the outer layer when employing the condensation system? As when wet would it not allow water to run down the inside of it, or would it (ironically) be too dry?

cheers

 

[Graham O]

Graham,

Have you tried, or indeed do you think it would work, to have ventile as the outer layer when employing the condensation system? As when wet would it not allow water to run down the inside of it, or would it (ironically) be too dry?

The concept of the condensation system, i.e. breathable fabric to wearer, spacer, then outer fabric was reliant on the outer fabric being as waterproof as possible and neoprene coated nylon was to hand and is very waterproof and durable. To get rid of the condensation, there must be no water absorbtion to restrict the flow of water downwards, (by gravity). So Ventile would not work as it would tend to absorb some of it. We had very waterproof garments in the neoprene nylon, but their comfort was low due to their lack of breathability. The idea of the spacing was to separate the two functions of waterproofness and breathability.

Hope that helps
Graham

 

[bushtuckerman]

It does, thanks

 

[Wink]

The concept of the condensation system, i.e. breathable fabric to wearer, spacer, then outer fabric was reliant on the outer fabric being as waterproof as possible and neoprene coated nylon was to hand and is very waterproof and durable. To get rid of the condensation, there must be no water absorbtion to restrict the flow of water downwards, (by gravity). So Ventile would not work as it would tend to absorb some of it. We had very waterproof garments in the neoprene nylon, but their comfort was low due to their lack of breathability. The idea of the spacing was to separate the two functions of waterproofness and breathability.

This is how my Keela Munro is supposed to work, I think! The outer layer is a normal "breathable waterproof" fabric. The inner layer is a wicking layer, but also with a membrane on, so you have an air gap between two waterproof breathable membranes. The two layers are not directly joined at the bottom of the jacket, there being a mesh filled opening for the condensation to run out. The upshot is that the inside of the jacket (where it matters) feels dry, although in heavy rain the outer fabric may have wetted out, and there could be a reasonable amount of water in the gap. This is a considerable improvement over conventional goretex, I think, where condensation has nowhere to go, although goretex would be more breathable in the dry due to one less membrane layer.

To return to your experiments though Graham, I can't understand why the twin layer jacket with mesh should work out so expensive? If, as you say, the inner layer doesn't have to be ventile, surely it should be the same sort of cost as a single layer ventile, plus a bit for the mesh and lining fabric (normal cotton?). Or is the mesh expensive to produce? It sounds as though you could have a pretty good bushcraft/country sports garment solution there!

 

[Graham O]

Hi Wick,
You are right in saying that your Keela jacket works in a similar way and I agree with your comments that it is a considerable improvement over conventional Goretex and similar fabrics. However, a double layer Goretex would also work as well. The trick is in making the lining layer as breathable as possible with the lightest weight. Since it is protected by the outer layer, it is immune to abrasion to a large extent.

The original jackets worked out a lot more expensive due to two layers of Ventile plus the mesh. This was quite expensive. But the biggest cost was in labour. It was not possible to just stitch all 3 layers together and it was necessary to adopt 3 dimensional stitching similar to box quilting on sleeping bags. And being quite large and bulky, the jackets needed more manipulation during sewing which reduced the throughput.

Part of the problems we had with the design was that the product requirements were very strict. If we reduce those, we can get away with simpler fabrics, meshes and products. While doing some new product development over the next few weeks and with some cheap Ventile arriving this morning, I may revisit the concept and produce a trial garment or two.

 

[bushtuckerman]

Sounds like you're going to be having some fun with it. Might you adopt new produciton techniques to reduce cost? or are there none?!

look forward to hearing about your progress

 

[mark a.]

All very fascinating. I'd love to hear more, so do keep us updated Graham.

 

[Wink]

Hey, guess what I just found?

http://www.peglers.co.uk/1_Keela-Ventile-Jacket.htm

A ventile outer, with a breathable wicking waterproof liner. Olive green, long, loadsa pockets, removable hood. But it doesn't appear on Keela's own website unless you use the search function. Uh?

Anyone seen one in the flesh... or better, used one in the rain?