Vega Jkt. What on earth is the point of a water resistant zipper if the jacket is stitched through. If you are stitching through (creating leak points) to save weight then why add the weight of a coated zipper?????
Further more - did any one look ont the breatability of this driite fabric? Surely welding down products is only beneficial if the fabric can breath at a greater rate than the wearers body can perspirer...if not you have simply place the down in a vapour shield.....
As for the Drilite ME use in down stuff (there's "Loft" for down products, and then the completely different "Plus" and "Extreme" for waterproof gear), I've been using sleeping bags and down jackets in Drilite for years now, and the breathability has never been an issue. The main point of welding here is so down doesn't get out through the stitching(it may also give weight benefits), there should still be plenty of breathability in the main baffles.
Hi guys As the designer, the person responsible for fabric sourcing, and the person that looks at all the fabric test results I guess I am the one you need to speak to.
The Vega / Sigma is currently our lightest 700+ fill power, helmet compatible hooded, down jacket. You are correct in saying we have used stitch through construction on the Vega / Sigma to save weight. However, other features of the design are based around the intended environment the jacket will be used in and the types of activities the jacket will be used for. As Jon has mentioned in the report, the jacket was designed with Alpine conditions in mind. This means we believe there is a high likelihood that the jacket will be used extensively in and around snow. It is for this reason we have used our water resistant (1.5m hydrostatic head) Drilite fabric and also the W/R zippers. There is not a huge weight penalty for using W/R zippers but you gain valuable protection against water ingress, which great for your down and warmth. We also use the Drilite fabric inside the hood for example so you can put it on over a wet climbing helmet or for when some snow get in the down will not get wet. There is a compromise between weight and protection but we think we have got the balance right for these particular jackets.
If however you wanted the out and out lightest down jacket from us you would pick something from the Xero range. The Xero Jacket uses the same quality of down, a much lighter shell fabric, which offers a lower level of protection against water ingress (470mm hydrostatic head), stitch through construction, and standard zippers. It does not come with the helmet compatible hood though. We have been using our Drilite Loft fabric successfully for many years (much longer than I have been at Mountain Equipment) across our Extreme sleeping bag and Down clothing ranges. Our new lighter Drilite fabric has been developed specifically for us after 18 months of development with our supplier. It has been tested at a number of independent test houses, including the University of Leeds, and offers the same performance levels as the old Drilite but at a much-reduced weight.
The Omega Jacket uses welded internal box wall stripping to the inside of the Drilite shell fabric. This does mean there are very narrow strips of a very thin lamination film joining the stripping to the shell. There will be some reduction in breathability in those specific areas but the overall surface area of the film is relatively small compared to the overall fabric surface area. Again this is a compromise between the protection of the down, elimination of down leakage on the majority of seams, and breathability. Other product teams may go in a different direction.
Thanks for your speedy response. I really appreciate you taking the time.
Let me start by apologizing for the tone of my original post. I'm new to this site and did not realise I was posting on a public forum. My original comments were intended for the guys at Outdoors Magic.
But now that we're up and running in a public forum.......
.....my contention is that in a traditionally sewn down product a large portion of vapor transfer occurs through the stitch holes in the fabric rather than through the fabric itself.
So Pete may well have used a drilite bag for many years without any moisture issues, but this may change in in a welded product.
When using a welded construction you eliminate the ability for air and vapor to move through the needle holes in the fabric. This theory is based on my observations from owning one of the first generation of Mountain Hardwear Conduit welded sleeping bags. This bag has nearly killed my on several occasions with the "4am freeze" a phenomenon where you go to sleep toastie and warm and wake several hours later with a completely deflated and damp heap of down on top of you.
So I guess what I'm really questioning is "what is the appropriate use of these new technologies?" and "Are companies really spending a long time field testing these products and ideas before bring them to Market?" No one who has actually slept in the sleeping bag I own would have thought that they were on a winner and taken this product to market.
Carl, MH's "Conduit" is a thoroughly different beast to Drilite loft, so you're not comparing like with like. Conduit is a fully waterproof material used in shells and DL-L is a water resistant material. There are, accordingly, going to big differences in breathability.
ME used to make Goretex shelled sleeping bags as part of the standard range. They don't any more, or at least if they do they're being quiet about them, and feedback from Real Use was not good. They also made Goretex shelled down jackets, and same applies to the current range. Goretex is a lot less breathable than DL-L. But even the old flavours of Taslan Goretex 2 were probably more breathable than Conduit: as our Leftpondian friends might say, "you do the math"...
Let's take a counter example: Op Pad did breathability tests of soft-shell jackets in a test a couple of years ago. The winner, by a country mile, was the Patagonia Ready Mix with welded seams. The base fabric, since it takes up most of the area, will have a lot more effect than the seams.
For field testing I can't comment on individual company policies, but certainly quite a few get out there and work the things pretty thoroughly.
Hi Carl I am happy to answer questions when I get the chance. I also know Richard our Product Manager comes on here from time to time…especially after some of our new kit gets posted up. However, the last thing we want is for people to think we are jumping on them whenever they mention one of our styles. We value the feedback and we are just trying to be a bit more interactive. We also try not to be too biased towards our own product and base our comments on factual information. To be honest, I have no idea about the actual ratio of vapour transfer through fabric vs vapour transfer through stitch holes in a box wall construction jacket or sleeping bag. I can say we have had a welded box wall jacket in our range since 2006 (Gasherbrum) and the 1st version of the Omega in 2007. These have both been used extensively and we have had no feedback regarding breathability / condensation issues leading to damp down. There is of course a more immediate response to heating up or cooling down when wearing clothing…you open a zip or adjust a cuff as you go. In a bag you only notice when you get uncomfortable and wake up. It might be too late to do anything by then.
Another option is the make up of a jacket helps eliminate this issue. There are still sewn seams on our jackets, as they can’t all be welded yet. A jacket also has a big opening at the bottom, another at the top, and if you want one, all the way down the front. A fully welded sleeping bag (this is all the major seams not just the stripping) only has an opening at the top and possibly one down the side. You are right in saying there is a reduction of opportunities for the moisture vapour to pass through the sleeping bag compared to a traditionally sewn one.
If we ever make a fully welded bag I will check.
- We do make GTX shelled bags...they tend to be black for some reason
As my name has been mentioned and you poor lot have to put up with my mug shots wearing some of our new jackets I will just add a couple more points - specifically to the question raised about the application of technologies and specifically how we have applied them to down products.
We will then disappear into the product developement ether!
Welding down products does not save weight. Tests have shown that it may not add any real weight either but it certainly does not reduce it. This is different to welding a shell garment etc where welding can reduce weight.
The reason for this is that, to our knowledge, there is currently no way of welding the internal baffles (usually downproof mesh or fabric) themselves to the outer shell. As such the baffles are sewn to fabric strips, which are then welded to the outer shell. In effect there is an extra construction process and extra componentry used.
In down jackets, the extra processes involved do not add particularly to the overall weight since the number of baffles and internal workings is usually fairly limited. This is not the case in a sleeping bag or one-piece suit where there are considerably more baffles and strippings. If we were to weld one of our Extreme bags for example (which we have done for tests) the weight goes up considerably.
The benefits of downproofing and weather resistance in this case are outweighed, in our opinion, by the need for the sleeping bag to be low in weight relative to its warmth.
An insight into one decision, amongst hundreds we make every year!
Richard Talbot - Product Manager - Mountain Equipment
As I haven't seen the jackets in question, I can't offer much comment on the design. However, IF there is no equivalent of an internal storm flap behind the zip of these jackets then it does make sense to use a water-resistant PU coated zip just for the sake of improved wind resistance.
I bought a "casual" down jacket from a Timberland clearance outlet - 24 Euros for a 650(US) fillpower jacket was too good to miss. And it is pretty functional. But one major flaw is that it has a standard zip and no baffle/storm flap behind. Even quite light wind can penetrate straight through to the inside creating a cold channel down my middle. Brrrr.
The true domain of the down jacket is cold, dry (and often windy) environments; design elements that help keep out the windchill are worth the added weight, otherwise this can be a serious chink in the armour.
As for the breathability or otherwise, the seams only become a major factor if the fabric itself has poor breathability IMO. Unless the outer fabric of a down product is very breathable, it is bound to suffer condensation problems. You are at the wrong end of the temperature gradient (and equally at the wrong end of the relative humidity gradient) when you get close to the outer shell of a sleeping bag. In cold weather, the dew point is likely to be well inside the insulation. The only fully waterproof shell that even tempts me is the eVent outer offered by Crux as standard in their Torpedo range and by a few other manufacturers as an option (e.g. Feathered Friends). And even this seems to be overkill (and extra weight) given the impressive HH measurements on many DWR & encapsulation techniques such as EPIC.
Unfortunately, as we have grumbled many times on OM, comparative information for proprietary fabrics is hard to come by. Our ME chums have kindly given us some idea of what their fabrics can do varying from 0.47 to 1.5m HH. [P.S. many thanks for appearing here - always a pleasure to see manufacturers involved in these forums]. If only all manufacturers were so candid!
