Feb 8, 2011 at 10:02 am #1268869
@newtonLocale: Southeastern Louisiana
Copied and pasted from a post by Roger Caffin on another thread.
"Stock American silnylon is just too porous to be acceptable any more…"
I have seen this and statements like it posted on various threads here on BPL lately.
Is this really as bad as it sounds. Is there really no acceptable silnylon for us MYOG shelter types without resorting to imports?
Who actually has the good stuff?
NewtonFeb 9, 2011 at 6:44 am #1694415
FWIW, Ray Jardine's kit page claims they treat their silnylon with some proprietary process to increase weatherproofing. I have no idea what that really means. I can say I made a tarp from his kit several years ago and it has served me well through heavy rain – no misting through.Feb 9, 2011 at 8:38 am #1694452
How porous is too porous?
Silnylon available in Europe is rated at 2000mm hydrostatic head *after* abrasion.
How does that compare?Feb 9, 2011 at 8:46 am #1694455
Most silnylon used here has a HH of about 1200mm. The issue is misting, which can and does happen in very high pressure rains (even the Tarptent.com website acknowledges this).
Lightheart tents makes its non-custom tents in China, where they have confirmed using silnylon with a HH of closer to 3500. Of course, it is heavier after this impregnation. Maybe 1.4 oz per sq yd?Feb 9, 2011 at 9:24 am #1694465
@owareLocale: Steptoe Butte
To nearly triple the resistance to water under pressure, you would need to increase the
coating weight by a lot more than .05 ounces per square yard.Feb 9, 2011 at 9:31 am #1694471
Just going by the marketing garble that comes from most manufacturers. From the Lightheart Gear site:
"What materials are LightHeart Tents made from? The body of the LightHeart Tent is made of 1.1 oz. sil-nylon (silicone impregnated ripstop nylon). The floors are made of 1.1 oz. sil-nylon (silicone impregnated ripstop nylon)."
"Is Sil-Nylon waterproof? Yes, sil-nylon is extremely waterproof within normal conditions. The standard gray tents come with sil-nylon that has a hydrostatic head specification of a minimum of 3500mm water. This is about 3 times the waterproof rating of standard sil-nylon."
So either someone has their head up their azz or they have access to something that others don't.Feb 9, 2011 at 9:45 am #1694480
MLD and ThruHiker collaborate on silnylon and do independent testing to verify quality.
I recall about two years ago when they found all silnylon was failing due to some manufacturing process problem.
So, unless someone can provide first hand, independent, test results, I believe you are at the mercy of the marketing spiel.
Faith baby, you gotta have faith, cause science is way behind.Feb 9, 2011 at 10:22 am #1694493
Marc and Judy have all of the requisite documentation on said fabric, I was talking with Judy about it just the other day. It has been suter tested and certified to the numbers they claim on the site.
The fabric in the gray standard model tents does come from Asia, it's sourced there, since the tents are manufactured there. They're working on trying to import some of said fabric.
I'm not sure what the difference is, but it's related to more than just "how much coating" is on the fabric.Feb 9, 2011 at 10:48 am #1694508
@marcpenLocale: Western NC
I have the lab analysis certifications for both the gray and black sil-nylon tested in multiple locations from selvage to selvage that was used in our standard gray body/black floor tents (both Solo and Duo). I even have pictures of the Suter Test device in action on our materials showing the 3500 mm H2O reading on the pressure gauge as taken by our contracted witness. It also shows the sil-nylon material in the holder and there are no droplets showing. In fact, the material tested to over 4000 mm H2O but was blown off the sample holder device by the high pressure just above 4000 even though it had shown no leakage at that point.
The weights of our manufactured tents is extremely close to the weights of our custom made tents using US made sil-nylon (there are some slight manufacturing differences between the tents Judy makes and the manufactured versions) so my best estimate is that the materials are essentially the same weight (at least within our scale's accuracy and repeatability).
How do they do it? I am not sure but it is obviously not just thickness of the coating. I know it is not a pure silicone coating but I don't know the actual composition. We had a lot of discussions about whether to go with this upgraded material as we had the choice to use a lower hydrostatic head sil-nylon at a lower cost. In the end we decided to pay the extra money for the 3500 mm H20 material just to deflect the misting concerns. We think it is worth it.
LightHeart GearFeb 9, 2011 at 10:50 am #1694509
IMHO, given these validated tests, I am looking toward the Lightheart for my next shelter purchase. I am tired of the misting issues I have had with previous apparent waterproof shelters.
Thanks for posting Mark.Feb 9, 2011 at 11:02 am #1694514
This is what I can tell you about the Asian silnylon. They use a type 6 yarn. This is not nearly as good as the high tenacity type 6.6 used by most Domestic mills. This lower quality Nylon has more stretch and less strength. Asian mills follow no Mil-Spec or ASTM standards so the material varies from roll to roll with some rolls having weaving flaws, frayed fabric, and coating inconsistencies throughout. Are some mills the exception? I am sure but overall their materials are of inferior quality..Feb 9, 2011 at 11:26 am #1694526
@davecLocale: Crown of the Continent
I just buy (shelters) from MLD and call it good.Feb 9, 2011 at 11:35 am #1694532
Lawson writes " This is what I can tell you about the Asian silnylon. They use a type 6 yarn. This is not nearly as good as the high tenacity type 6.6 used by most Domestic mills. This lower quality Nylon has more stretch and less strength. Asian mills follow no Mil-Spec or ASTM standards so the material varies from roll to roll with some rolls having weaving flaws, frayed fabric, and coating inconsistencies throughout. All the Asian silnylon I have seen is junk."
Operative phrase in that statement being "All the Asian silnylon I have seen". I may be mistaken, but I seriously doubt that Mr. Kline has actually been to Asia. So to make a blanket statement like this is frankly pretty silly. Yes, you can buy pretty crappy stuff in Asia and you can buy some really good Nylon 6.6 there also.
Yes, you can get fabric that meets ASTM standards and probably Mil-Spec. But that one I'm not sure. The reason the military buys US made goods is because it's the law (Berry Law to be exact). Not because you couldn't buy the same quality on the foreign market.
As to Rogers comment about "American silnylon not acceptable", that too is a matter of opinion. In this case his. We've sold thousands of tents that are used in harsh environments around the globe. It's been a long time since anyone's contacted us about having a misting issue. Currently all of our silnylon is US Domestic source.
It's a little easy to get carried away about all of this.
One should also note that until about 50 years ago, all tents made misted. It wasn't until tents started to be made from coated nylon that misting became a thing of the past. Tents made from either canvas or silk, didn't have coatings. They relied on the swelling of the yarn when wet to keep out the rain. Still under heavy rain storms, one could still experience misting. I know because I slept in canvas tents until I was 20.Feb 9, 2011 at 12:08 pm #1694540
@erdferkelLocale: S. California
The official ones look expensive, but it seems like you could make one with a piece of pvc standpipe somewhat like this:
SPOT testing at equipped.com
3000 mmH2O is ~10 feetH2O so not too tall. The only trick is to seal the end with your test piece of silnylon so you can see the water drops press through, maybe a threaded fitting with a plug with the center cut out?Feb 9, 2011 at 12:25 pm #1694550
Misting is a big concern of mine as well. I use a 8 year old Equinox silnylon tarp, 5 year old BD Megalite, and my brother has a 2 year old Equinox tarp. None of them have ever misted. I can't say the same about my TT Rainbow or SMD Refuge.
On my last trip I abandoned my refuge for the second night of rain because of intense misting that wetted everything in the tent. To be fair I could have potentially reduced the intensity of the misting, wiping condensation from the inside roof and leaving the screen door open. The misting in the Rainbow wasn't as intense but neither was the rain.Feb 9, 2011 at 12:43 pm #1694555
@foundLocale: Sacramento, CA
I'll chime in that I've long been disappointed by silnylon's waterproofness….Feb 9, 2011 at 12:45 pm #1694557
"(Berry Law to be exact)"
The Berry Amendment, to be more exact. And it's a slightly misunderstood amendment as it stands now. It only requires DoD to "give PREFERENCE in procurement to domestically produced, manufactured, or home grown products, most notably food, clothing, fabrics, and specialty metals" [Wikipedia entry]. It doesn't require all purchases be domestic. FWIW.Feb 9, 2011 at 12:49 pm #1694558
If Asian silnylon is so good why don't you use it?Feb 9, 2011 at 1:03 pm #1694567
@hikinggrannyLocale: Gateway to Columbia River Gorge
Greg, that problem 2 years ago was with spinnaker fabric, not silnylon. Not only MLD and Thru-hiker but also Gossamer Gear ran into issues. I had to wait over a year for my now-beloved Squall Classic! Fortunately the new spinnaker–when they finally got it–tested out better than the old. However, I recently saw on Thru-hiker that the problem of spinnaker quality has arisen again.
I haven't had any misting issues with silnylon, even in heavy rains. I weathered a number of Colorado cloudbursts (several every evening for a week, about 30 min. of torrential rain and hail with each) with a SMD Lunar Solo with zero problems. Lots of condensation, yes, which the hail in particular tended to knock off the tent wall (as did my dog's tail wagging!), but nothing coming through the fabric except for one tiny spot on the horizontal seam that I missed in my initial seam sealing. I have two larger silnylon tents (Tarptent Squall 2 and Rainshadow) that have been in extended heavy rain with no misting. I also have silnylon rain gear which has had zero leakage since I seam-sealed it. Maybe I've just been lucky, but I personally have never experienced a misting problem.
Like Ron, I grew up in the days when you didn't dare touch the inside of a tent when it was raining! Maybe that makes my perspective a bit different.Feb 9, 2011 at 1:04 pm #1694568
@owareLocale: Steptoe Butte
"Misting is a big concern of mine as well. I use a 8 year old Equinox silnylon tarp, 5 year old BD Megalite, and my brother has a 2 year old Equinox tarp. None of them have ever misted. I can't say the same about my TT Rainbow or SMD Refuge.
On my last trip I abandoned my refuge for the second night of rain because of intense misting that wetted everything in the tent. To be fair I could have potentially reduced the intensity of the misting, wiping condensation from the inside roof and leaving the screen door open. The misting in the Rainbow wasn't as intense but neither was the rain."
Do you think the angle of the shelter's pitch would change anything in you experiences?
Do you set up your older tarps using the same angle of pitch as the rainbow or refuge?
A steep pitch would lessen the force of rainfall.
In my experience in using surplus parachute silks for survival shelters, steep sided teepees can be made of UNCOATED 1.1 oz nylon that do a pretty
good job of keeping out weather, and two layers of it will do as well as any coated fabric. (I would in fact use a 2 layer dwr pyramid if I did a lot of cold weather trips
over a 1 layer coated mid.)
Take that same fabric and make a very shallow lean-to and rain will penetrate.Feb 9, 2011 at 1:16 pm #1694578
I'll be using an Asian Silnyon on my new tent. I don't currently use it on shelters built in the US.
The reasons I don't use it for shelters built in the US are not all that complicated.
1) Importing Fabrics with customs, shipping, etc. is a real headache. Right now we only import Dyneema and we use significantly less of it.
2) Fabrics are purchased in dye lots. In the US I can purchase smaller quanities and have multiple colors. This gives our customers more options.
3) Lead times are small. I can place an order today and have it in house and cut into parts in a week, yesterday ordered fabric for a new production run. In a couple of weeks I'll order more for a different tent.
Going overseas, they don't even schedule the production until you place the order and make partial payment. Then it needs to be woven, dyed, coated, packaged and shipped. Start to end you're looking at three months maybe more.
The result is I've got to tie up a large amount of money before turning a profit.Feb 9, 2011 at 1:24 pm #1694584
Are your products now going to be made in Asia?Feb 9, 2011 at 1:27 pm #1694586
.Feb 9, 2011 at 1:31 pm #1694591
That tube test is exactly what I did some time ago just to try it out for myself.
I cannot remember the exact details , I did post some here at BPL, but essentially it demonstrated to me that the TT silnylon (or the sample I used…) has a waterhead of around 1200mm.
My test was over several hours( over 5) allowing 3 water drops in that period .
However I have since read this comment from the MSR site :
" a 1500mm coating will withstand a 1500mm (5') column of water for more than one minute before a single drop might appear through the fabric. That's strong enough to prevent rain from leaking into a tent in a hurricane-force storm. "
Having done that I then coated some with a very highly diluted mix of silicone and mineral turpentine and that took the WH to around 2000mm. I also sprayed another sample with McNett "Thundershield silicone waterproofing", from memory that increased the WH from around 1200mm to about 1500mm. (i did a very light spray twice)
No real idea of the added weight because the sample was too small (6-7" square) for my scale to register the difference (5g increments)
I have however not sprayed or coated my shelters because misting in mine has never been enogh for me to worry about it.
see this video for the type nof conditions I am talking about :
That was the tail end of cyclone Yasi passing Melbourne.
I don't carry a video camera hiking.
I do understand that some find seam sealing/spraying /coating unacceptable however I am used to maintain my gear . I grew up using full leather boots (you know Italian leather/Vibram soles…) and have had bikes all my life… so to me it is normal not a burden .
FrancoFeb 9, 2011 at 2:02 pm #1694604
Six Moon Designs has been in business for 10 years and all of our manufacturing is US based. We've been fortunate to secure a good US production source with reasonable rates and excellent quality. However, we've grown large enough that if something were to happen to our production we'd be out of business in short order. To spread the risk, we've decided to move some production offshore.
For the record, this is the hardest decision I've had to make since starting SMD. Unfortunately when it comes to producing the kinds of goods we sale. The US has become a 3rd world nation. Moving offshore is not just a matter of cost. We have access to capabilities I can only dream about.
We're also becoming a more global company. We've got a distributer starting in Japan and in discussion with one in Europe. Doing some international production lets us setup more direct shipping to foreign countries.
That said, I'm still commited to keeping as much production in the US as possible. I love the short turn around from idea to product. Plus we can do smaller production runs for products that we'd have to drop if we needed to produce large quanities.
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