Silnylon sagging, tents falling down…

[Franco Darioli]

Apparently some tents fall down as soon as you look at them.
Maybe setting them au correctly helps.
After my peg test , at the start of the clip, I left the tent up as we were expecting high winds.
The next morning (this morning) it started raining so after an hour or so I wanted to show what happens when
silnylon sags and how you fix that. As I was doing it a storm crossed over causing me to retreat because my camera was getting wet, and so was I…
So I had no time to tie down the sides because I wanted to keep filming ..
When the storm eased off for a moment I tied one side down and you can see the immediate improvement, less side deflection.
About half an hour later the storm had passed so I filmed the inside of the Contrail.
Hard to see but the floor is bone dry apart from some fine sprays along part of the left side looking in , the one that was not tied down at all.

http://www.youtube.com/watch?v=9V3gKohpfCY
Franco

[Lynn Tramper]

My cure for sagging tents is to attach a loop of bungy to each tie-out/stake point. By stretching this taut when I pitch the tent, the tent will usually maintain it's taut pitch as it the fabric stretches with cooling.

[Bob Gross]

Cute video clip. I thought the raindrops on the camera lens made a nice creative effect.

–B.G.–

[Franco Darioli]

I am using a crappy wide angle adaptor so after a while the camera started to focus on the raindrops on that. I edited that out.
Unfortunately I missed the best bits because after I got soaked the lens got stuck on tele and took me a while to get it working again.
(I bumped the front, not recommended but 30 years of camera retailing comes handy at times…)
I should really have one of those smaller weatherproof jobs but they all record MPEG4/AVCHD and the like, hard to edit.
Franco

[EndoftheTrail]

"Maybe setting them au correctly helps."

"au correct" meaning Aussie way is best? Huh? :)

[Bob Gross]

"I should really have one of those smaller weatherproof jobs but they all record MPEG4/AVCHD and the like, hard to edit."

But, Franco, if the job had been easy, we would have sent in an amateur to do it.

–B.G.–

[Franco Darioli]

Ben
Have no idea how that AU got there. It was just before lunch so I had something else on my mind..
Maybe was meant to be UP (?)
Bob
I had access to any camera I wanted and computers fast enough to do any editing. Not so now, so I am not that keen on flooding my own camera.
Franco

[john Tier]

JRB Self Tensioning Lines (STL)keep tent covers taut as well as just tarps…Currently on sale too.

Remember I'm biased.

Pan

[Barbara Karagosian]

Great video – nice green lawn too! What type of stakes were you using Franco? Thanks, Barbara

[Unknown abc]

Impressive how when you leaned almost your full body weight on the pole, the tent hardly budged!

[David Ure]

Well, I consider that a heavily sheltered site so not a good test at wind performance. I tried that once but being close to 100KG, the shelter budged. Hard.

[Lynn Tramper]

"Great video – nice green lawn too!"

Makes an improvement over some of his summer videos :0

I often notice it's not the force (as in weight applied) to the system that can undermine it, but the way the force is applied. A firm but continuous wind (as simulated by gradually leaning on the tent) is far gentler than a whollop of a wind gust which would be better simulated by a line-backer or league player running full force into the tent…I think that's why bungy cords work so well. They don't just keep your tent from sagging in the cold, but they moderate some of the force of the line-backer…!

[Franco Darioli]

I was using the 9" Easton .
This started because of a guy posting a video where his 2002 Squalls collapses after he slaps gently the apex.
I can do that too if I don't peg it down correctly.
The rest was because I wanted to address the sagging bit. My point was going to be that when it sags, you retention it once and that is it. It will remain taut after that.
The storm happened to pass as I was attempting to do that…
I would favour the bungy cords on a shelter designed to flex, like a hoop type , but prefer a fixed pull on this type.
I do however have bungy cords attached to this Contrail but are not in use .
Franco

[Quinn Nelson]

I'm guess this is somewhat of a reply to the video/thread The Nature Boy posted up over at Backpacker.com?

[Mat Tallman]

I surely cannot be the only one who has retensioned guylines during rain/cold only to have the tent sag further after that.

My last time out, I hiked all day, and pitched my contrail right at dark. Cooked and went to bed, tent nice and taut.

Fast forward a few hours of sleep, rain begins, tent sags. Canted trekking pole raised to upright/plumb, and most of the sag removed, back to sleep.

Few hours later, the tent has sagged further, and is again touching my bag. This time I get to go outside in the dark and rain to retension the thing. I get wet, and risk wetting my bag when I get back in the tent.

By the time I woke at sunrise, the tent was, again, sagging somewhat.

My experiences certainly do not support that one retensioning is all that is required with silnylon in rain. I was less than impressed.

I played around with bungie cord guyouts but found that the spring action made for less than desirable results in wind.
I suppose everyone's mileage may vary, but I think I'm done dealing with silnylon stretch.

I love the design of the contrail, and its' features, but the material selection is proving to be a deal-breaker for me. I'd love to see Henry begin using alternate materials for his tents..

[David Ure]

Mat, your experience is similar to mine under constant humidity conditions.

[Franco Darioli]

Mat
I have had the Contrail under most night/ all night rain, many times.
I calculated the difference between the fabric under hot sun and totally wet in cold conditions to be about 15% .
But again , once the fabric is fully stretched, and that happens usually half an hour to 1 hour in the rain (depending on air temperature and maybe humidity) it will stop stretching.

If you look at my video again, you will see that the Contrail is taut after my bump test. At that point the fabric is cool/cold (the air temperature was about 57f) , so somewhat relaxed compared to having it up taut in the sun.
Later after some rain, about I hour into it , it fully relaxed and that is when I went out to fix it. After that and after the storm passed it kept raining on and off , the shelter remained taut and so it was the next morning.
So 1 adjustment from dry to wet after prolonged rain.

Most likely what is happening is that the guylines slip through the line lock adjuster. Mine don't do that at the back but sometime do at the front of the Contrail and occasionally on the Rainbow. I think that it has to do with the angle. . So rather than pulling that in I reposition the peg.

Franco

[Steven McAllister]

Regarding:
"I surely cannot be the only one who has retensioned guylines during rain/cold only to have the tent sag further after that."

I have never had to do that under silnylon rectangular tarps, Tarptent Rainshaow, SMD Gatewood nor SMD Haven.

There may other things at play here?
Maybe my guy line materials compensate? I used a lot of different guyline types, so I doubt it.

Maybe I cinch my lines down tighter? I know my wife thinks I overdo it.

I pitch the shelter first thing and then re-tighten before I go to bed, as the temps are starting to fall.

I usually don't re-tighten in the rain, but have witnessed a slight sag, but still rigid enough to take the wind.

[Javan Dempsey]

Another angle that I've learned from personal experience, that might not have occurred to some here in regards to trekking pole pitched shelters.

Some trekking poles creep lower with constant applied pressure, especially if the expanders are damaged, or getting old. I've got one pole that is defective and does it pretty noticeably over the course of 15-20 minutes, which is how I discovered this personally, but with a few others that are fine, I've done testing that shows it happening much more slowly.

Bear in mind that these same poles (the ones that are fine), will not show any significant retraction during normal hiking use, except for the expected minor amount after the few few strikes.

Don't know if this is affecting anybody, but it did me with my TT, causing me to have to adjust/re-tension a few times.

[Chad Miller]

Quinn wrote

“I'm guess this is somewhat of a reply to the video/thread The Nature Boy posted up over at Backpacker.com?”

Backpacker.com , Pfft! We all know he doesn't actually backpack! I mean all he does is post online! :-)

[David Ure]

Steven asks if there might be 'something' else going on. Yes, there is. Climate.

Using silnylon in high humidity areas or where there are extreme temperature changes does cause issues. Not sure where you backpack, but bring one of your shelters to the West Coast of Washington or Vancouver and then re-post….; )

[Steven McAllister]

I mostly backpack in the damp NE coast of the US and I have seen my share of extreme temperature and humidity changes.

I have gone to bed on warm nights, waking to cold pouring rain and I use silnylon shelters 75% of the time.

I have also experienced the trekking pole creep that Javan mentions, but it was kind of obvious in my case.

I do admit that silnylon and any nylon for that matter will sag when wet. Nylon lines can sag as well.

Silnylon also has a lot of stretch, over tightening before I go to bed seems to be the best solution for me.

I suspect thick bungee would help as well, as long as it was thick enough to not give in a wind.

[Mat Tallman]

@Javan

I wish I could blame it on a slipping trekking pole, but mine are homemade jobbers that are constant length.

Sil isn't for me, but thankfully plenty of other people love it, so I shouldn't have any trouble finding a new loving home for my contrail once I get my next setup sorted out.

[Quinn Nelson]

@Chad

Im sure most, including myself, would agree with you.

[Eric Blumensaadt]

The Moment seems to overcome most of the "silnylon sag" problem with its hoop pole and shape design. I've seen is sag a bit in an all night rain but not the "15% stretch sag". If it did it wasn't readily apparent.

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