Concerning Shock Cord on Guy Line,Tarp Tightness and the wind with Input From Brandon

[SC_Dave]

I posted here recently about tarp tightness and shock cord. Got a lot of good information but I wanted to hear what Brandon had to say on the subject including wind. After all he should know the SF better than anyone. I hated to email him with a question because I am sure he gets hundred of those. But, I succumb and fired off an email. His response made a lot of sense to me and with his permission I am posting it here.
David

Shockcord normally only applies a very small amount of force unless it's extremely thick or stretched to where it's fully static, so i would say that if your shockcord is only partially stretched then it is only applying a few lbs of force to the tarp, in that case you're probably going to have a quite loose tarp that moves alot when the wind blows and makes noise, probably sags some etc, then when the wind is heavy the SC will stretch to it's max (stop stretching and become static). If it's fully stretched out to begin with then it basically acts like static cord all along so not really any different than normal guyline in how much tension it would put on the tarp(would simply be dependent on how hard you pull/pitch it)

If you're worried about a huge gust of wind causing damage, I don't think the shockcord would be providing any shock absorption under such a circumstance, because a heavy gust of wind is way more than enough force to fully stretch the SC to the point it becomes static... it would have plenty of shock absorbtion under very mild breezes that only apply a few lbs of force (when you don't actually need it), but would become fully stretched and static under moderate and heavy wind and not provide any shock absorption because at that point it would be fully stretched, now if you had something that took like 30-50 lbs of force to stretch it (rather than 5 lbs or less), then it might actually provide some shock absorption in heavy wind, but this would require something with maybe 10X the stretch resistance of normal shockcord. For it to actually work like you're wanting you'd want something that is dynamic under heavy wind load, while normal shockcord is dynamic under very low loads and static under moderate and heavy wind load. In my opinion it doesn't have even close to the resistence you'd need to make any difference in moderate/heavy wind.

Brandon

[Klaussinator]

Now this is interesting... and I don't think I disagree with him.

-Klauss

[SC_Dave]

Now this is interesting... and I don't think I disagree with him.

-Klauss

My sentiments exactly.....

[mountain_man_mike]

I use a stretch of shock cord to take up the slack, but have no hopes of it keeping the tarp taut under a heavy wind. In heavy winds, I am hoping it gives a little and prevents a tear. When the wind dies down I can resecure things and search for any gear that gets blown aside.

[samesons]

I have wondered about the benefit. I really appreciate the answer. Thanks for posting the email

[craige]

Those have always been pretty much my thoughts as well. I like a 4' piece on the doors to enter/exit the tarp though.

[ntxkayakr]

That is an interesting view and begs the question: What is the Sil-nylon used for Warbonnet's tarps rated at for tear strength and breaking strength?

www.rockywoods.com lists theirs for some 30 Denier Silicone Ripstop Nylon as 12 lbs and 77 lbs.
A back of an envelope calculation would tell me that if a single or loop of 1/4" SC or similar bungee etc holds a 24 lb weight and is not fully stretched out or "static" then it may protect a hemmed tarp (double layers of fabric at the edge). Which begs the question is this worth the weight and time/ trouble?

edit: I'm not good with english, probably should have said "raises the question" but there is some circular reasoning going on with shock cords and tie outs and their efficacy. Anything not properly implemented may not fulfill its desired purpose.

[SC_Dave]

I have SC on all of my SF tie-outs. Being new to hammock camping (2yrs) most things I read and most videos I watched talked about using it on tie-outs so I did just that. I'm now beginning to wonder if I need it. I think the next few time I go (which will be fall now) I plan to set up without it. We'll see what difference it makes.
David

[breyman]

Thanks for sharing - always fun to see the insight from our hammock pioneers - Brandon is definitely one of them.

Personally, I use zing-it on the ends of my superfly for tying off to the tree. I also have shock cord tensioners at the four corners of the tarp. I don't use them to absorb wind, though. I pull them fairly (although not all the way) taut so that as the tarp stretches overnight with rain and/or cooling temperatures, the tarp stays a bit more taut.

[Mountain Gout]

Not sure where this all started, using shock cord and all.. Maybe from the tensioners then a misunderstanding of why they were being used?.... I take very good care of my gear but I do not baby it..
When I set up my tarps they are tight, if using shock cord it is only on the doors..
Take a good look on how these tarps are sewn, there is nothin delicate about them..
Just guessing here but if folks are having problems with windy conditions, consider your method of setting it up in the first place...
The tarp should cut into the wind, not be an obsticle.. Just throwin this opinion out there..