- Feb 19, 2010 at 1:21 am #1575746Roger CaffinModerator
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> Weight: 2.22 Oz/yd2
That translates to about 75 gsm, which is close to the typical 70 denier nylon used on traditional tents.
Pretty heavy imho.
> Hydrostatic Resistance (Water Proofness) 123 psi
About 17 kPa, which is about the same as silnylon these days. Hardly great.
Summary – equivalent to cheap and nasty acrylic coating, or a typical heavy-weight EPIC imho.
CheersFeb 19, 2010 at 2:03 am #1575751
The tents appear to be largely unchanged, except for one rather displeasing facet of the updated hilight, which has trimmed 8 inches (on the taper) from one end of the tent. The footprint is no longer 50" wide for the whole width, but instead tapers to 42" at one end. I was always impressed with the roomy feel of the 50" wide rectangle combined with the steep walls of the previous version and bemoan the shift towards the narrow. I can only imagine that this has shaved but an ounce from the weight.Feb 19, 2010 at 3:53 am #1575759Brian ULMember
@maynard76Locale: New England
Ive always been a tarp kinda guy. None of the tarptents had me willing to make the switch as they were always a compromise.
But, these tents have my attention, freestanding, 4 season, as waterproof as silnylon and breathable, clean design, respectable weight.
Tye only question is whether the big open door on the highlight is worth the extra money. It looks like it would be better in the warm weather and give great views?Feb 19, 2010 at 3:45 pm #1576039Bradley DanylukBPL Member
"> Hydrostatic Resistance (Water Proofness) 123 psi
About 17 kPa, which is about the same as silnylon these days. Hardly great."
Really? Every single source I've read on silnylon says it's waterproof to maybe 2 psi at most. Osmo is 123 psi. Want to make sure nothing's being lost in translation here…
I can vouch for the utility of Osmo fabric. They claim it's more breathable than eVent, though in my experience I've found it just slightly less breathable – but still great. It also meets fire-retardency standards so it can be sold everywhere, unlike silnylon or eVent etc.
That said, it has an inner coating that is flaking off due to UV damage on my tent (60 days in uber-hot Italian and French summer). This made me think, "hey, is this just PU coated breathable fabric like everything else in the world?" but it's hard to explain the high breathability if it is.
Richard Nisley :
I'm not doubting your numbers, but they imply that silnylon is already completely overcome in a Light / Drizzling Rain. This is hard to corroborate with the masses of user experiences here, which seem to indicate that silnylon only starts to mist in extremely heavy rain. Your charts make Tarptents etc look completely useless against any kind of weather at all. Any ideas?Feb 19, 2010 at 4:31 pm #1576061Carter YoungBPL Member
@kidcobaltLocale: Western Montana
Last year we had both a Nemo Moki and a Bibler Bombshelter on the same trip, and neither leaked under .75 inch of rain during the night. As for breathability–it's hard to say, but the Bibler is more comfortable to be in because the fuzzy Nexxus inner of Bibler tents soaks up moisture like a paper towel. On the other hand, the Nemo tent's inner canopy surface can become quite moist–it has a white rubber-feeling coating similar to what's inside a Patagonia Storm Jacket. And I know from experience that Patagonia's H2No coating will flake off over time.
I once had a Nemo eVent tent with a Nexxus inner–it was quite nice for one rainy night until the seam taping started to peel off.Feb 19, 2010 at 7:20 pm #1576147Alex GilmanBPL Member
Agreed, something's not adding up. I've washed my Nano by hosing it off and it didn't leak. In fact I've concentrated spray on some spots where the dirt was caked on to get it to loosen up and wash off and it didn't "mist/shoot" through. If it's rated at 1700-ish I have a hard time understanding these figures something seems off.
Can you please elaborate?Feb 19, 2010 at 7:40 pm #1576156Alex GilmanBPL Member
I found this article and here's a snippet that really puts it in to perspective:
A fabric is classified as 100% waterproof if it keeps water at a pressure of 25 PSI from passing through it.
To put this into perspective, a hard rain generates about 2 PSI. While this doesn’t seem like much, any activity increases this pressure. If you weigh 170 pounds, just sitting creates about 7 PSI, while kneeling creates about 18. Now imagine bumping into boulders, trees, and wearing a backpack. Straps on a 40-pound pack can push the pressure to 30 PSI as it rubs and shifts throughout the day.
OSMO at 123psi is almost 5 times the amount required to be called "waterproof". This is hardly silnylon class.
Furthermore, their breathability in lab tets is rated higher than eVent and it doesn't have the fire dangers associated with those fabrics.Feb 19, 2010 at 9:02 pm #1576185
All fabrics are susceptible to fire – some more so than others. Fire retardant versions simply buy you a few more seconds when in direct contact with flame.
It seems to me that most tent fabrics will perform better in the field than in the lab when applied in a good design and used properly. Water is mostly hitting the fabric at angles and is deflected rather than taking direct hits for perhaps 80% of precipitation exposure. Snow use, which is what the Epic tents were originally touted for, of course entails a different set of variables where AATCC Test Method 127 would not necessarily apply.
So who is going to be the first to have one of these next to their scale? (Excluding Roger ;})
[click on the pic for a link to a testing lab if you need to order the test for a cuben sample, for example]Feb 19, 2010 at 9:09 pm #1576189
Copied from up above:
1200 mm Big Agnes Fly Creek UL 2
1500 mm Sierra Designs Clip Flashlight
1800 mm SD Clip Flashlight
2000 mm Kelty Ridge 2
3000 mm Mountain Hardwear Viperine 2
4000 mm Terra Nova Laser Competition
5000 mm Coleman Helios X³
10000mm Bibler Todd-Tex (single wall)
25000mm RAB Summit Extreme Tent (single wall)
To add another perspective, the Eureka "backcountry" tents are just about the cheapest tents out there that are still "rain proof" — and their tents are popular with scouts, etc. for "normal" three-season use (any cheaper and you get into junk territory with Wenzels and Swiss Gear and Texsport, etc.). For the record, those Eureka tents have just 800mm coating. I've always used 800mm as "baseline", below which I wouldn't ever recommend. The UL Big Agnes tent coatings are half again as much.Feb 19, 2010 at 10:02 pm #1576216
I've never had a tent leak or mist on me – even in southern thunderstorms having my tent set up for nearly 60 days in a row.
A foul storm on Mt. Rainier (blowing slush) convenienced us while testing a Bibler Tempest next to a prototype Kelty Assault tent, which had a Titantex fly (which I am yet to see on other tents). It had a thick waterproof coating on the outside of the fabric that was aimed at reducing weight and the effects of UV at altitude. It seemed very fragile and susceptible to abrasion (reminiscent of Cuben, but with a coating). I don't know what the hydrostatic head results were on that fabric, but the driving sleet up there did not penetrate that material under a very taut pitch with cross-winds. The tempest also did fine and was a better performing tent overall, but the Kelty was near 4 lbs. with 2 people. I would have loved to have had one of these BD tents up there then! Perhaps the opportunity will yet arise.Feb 19, 2010 at 10:24 pm #1576230
Sorry, which tent are you referring to above? I'm losing track…Feb 19, 2010 at 11:01 pm #1576246
All ;)Feb 19, 2010 at 11:02 pm #1576247
LOL — you are not helping! :)Feb 20, 2010 at 1:01 am #1576257Franco DarioliBPL Member
@francoLocale: Gauche, CU.
Titantex was rated at 1800mm .
FrancoFeb 20, 2010 at 7:58 am #1576297Richard NisleyBPL Member
@richard295Locale: San Francisco Bay Area
You said, "To add another perspective, the Eureka "backcountry" tents are just about the cheapest tents out there that are still "rain proof" — and their tents are popular with scouts, etc. for "normal" three-season use (any cheaper and you get into junk territory with Wenzels and Swiss Gear and Texsport, etc.). For the record, those Eureka tents have just 800mm coating. I've always used 800mm as "baseline", below which I wouldn't ever recommend."
I think you are mistaken about the hydrostatic head of these flies. Besides, double wall tents very effectively mitigate fly seepage… so much that you can't detect it.Feb 20, 2010 at 8:19 am #1576302
You are confused with the term "backcountry" tents as Eureka uses the term (notice my quote and the plural up above). The term refers to Eureka's category of tents.
The model(s) favored by scouts, etc. — such as the Timberline 2 and Apex 2 are 800mm . The flies are rain proof. I also haven't read of any complaints about floor seepage either — which are also 800 mm.Feb 20, 2010 at 8:22 am #1576304MIchael MacCormacBPL Member
excuse my ignorance, but does anybody else find it strange that there were many posts about how BD epic tents would wet out after any prolonged or significant rainfall but there were people who doubted silnylon misting was from rain going thru the fabric YET the difference in hydrostatic head pressure is only 100 mm.
Is that due to design differences in the flys? Where BDs tents more likely to have horizontal roof sections?
Anybody more knowledgeable care to explain?Feb 20, 2010 at 8:42 am #1576311
nmFeb 20, 2010 at 8:48 am #1576316
I think Michael is on to something – the shape of the fly, shelter, and how taught the fly is may have varying effects as well. But I also agree with Richard – I think most double walled shelters mask the ineffectiveness of a relatively low HH of a fly.Feb 20, 2010 at 8:56 am #1576319
"But I also agree with Richard – I think most double walled shelters mask the ineffectiveness of a relatively low HH of a fly."
But that doesn't explain why the same 800 mm floor coating protects against water seepage. Sitting on the floor that covers a small puddle exerts much, much, much more pressure than any thunderstorm this side of the universe!Feb 20, 2010 at 9:11 am #1576321Diplomatic MikeMember
@mikefaedundeeLocale: Under a bush in Scotland
There must be more factors at work here than HH. I've been using silnylon shelters for years in Scotland and never had any misting or seepage, despite often camping on sodden ground.
I've been using a polycro groundsheet since i 'discovered' the stuff, but i never had any problems before either. I use the polycro to help against ground condensation and keep the floor clean.Feb 20, 2010 at 9:12 am #1576323
True, but not if the site is well chosen and there is very little, if any, standing water.
I have had water come through the floor of a tarptent because of a poorly chosen site.Feb 20, 2010 at 9:30 am #1576330
You missed the point, David. I was saying essentially that 800mm HH works effectively as a barrier against water penetration — even with the incredible pressure of a hiker's fat ass pressing the floor down against a small puddle of water underneath! Site selection is completely beside the point. :)
Methinks there's a lot more than just looking up an HH table when shopping for a shelter's rain/puddle resistance.Feb 20, 2010 at 9:49 am #1576337David RowenhorstBPL Member
@row435Locale: Mid Atlantic
I had to do a little digging on this. I'm always very skeptical of anything labeled nano, mostly because it is much more branding than any real nano scale affect.
This stuff is nothing more than a Silicone spray (note: silicon -> computer chips, silicone -> bathroom caulk). Maybe these guys figured out a slightly better delivery system, but nothing new here, the stuff would act essentially as a DWR coating, wearing off with time. Making a polymer film 100nm thick is nothing special.
Claiming that it is a "glass" coating is misleading at best, boarding on deceptive. Just because it contains SiO2 doesn't make it glass.
Edit note: the above only refers to the "Spray on Glass" linked above. It appears as though the BD Nanosheild is also a Silicone treatment, but my guess is that it is bonded to the fabric in a much more durable fashion. I still think the "nano" half of Nanoshield is just marketing. No real nano tech here, just the same tech we have had applied somewhere else. It used to be that we did this with Titanium.Feb 20, 2010 at 10:15 am #1576344
Hey Ben – no I got your point. My counterpoint was that I have experienced a soaking floor made of fabric (silnylon) rated to 1200mm. I don't consider my ass fat but YMMV….;)
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