Aaaaah! Apologies in advance: Trailstar – Silnylon vs Cuben Fiber

[Peter Atkinson]

I've searched this site and i've no idea if I've missed it, but is there a thread on the above topic?

There are lots of Trailstar users on here and in the UK, and I feel a bit late to the party… but my home-made cuben pyramid isn't really doing it for me…

Can I ask, dare I ask…. without looking too buffoon like: how hard is the cuber Trailstar to pitch?

I'm convinced it's the tent to use it's stable, you can use it with just a groundsheet and no bivvy, even with down.

But would I struggle getting a good taut pitch with cuben? Or stick with Silnylon?

I'll be using the tent in Scotland/Howgills/Lakes – the usual spots for the UK…

Any chance of some thoughts/advice (he asked embarrassingly…)

Oh woe!

[Ben C]

I really have not had any problems pitching my cuben TS. Pitching this geometry requires you to get into the right mindframe, but once I saw it pitched the first time, I have not had any problems.

[David Ure]

Have you read Chris Townsends review? He much preferred the silnylon version for the conditions you describe.

[Jason Elsworth]

http://www.pbase.com/flying_fox_tony/dartmoor_trailstar_july_2012

http://www.pbase.com/flying_fox_tony/mld_cuben_trailstar

http://www.youtube.com/watch?v=7vmneOE4j2s

http://flyingdogphotography.blogspot.co.nz/2012/10/my-thoughts-and-opinion-on-my-mld-cuben.html

For UK use I would go for the Sil version every time. If you want to go Cuben I would get a Duomid.

[Peter Atkinson]

Thank you for the feedback – my heart says cuben but after reading the information you've helpfully pointed at, my head says silnylon!

[James Marco]

Cuben "cloth" really isn't a cloth. Silnylon is. Many of the percieved differences between the two can be traced back to the simple construction methodes between them. The raw strength between silnylon and CF is mostly percieved by the different weights of the material (and coatings) between them.

Silnylon is a treated cloth. The treatment is silicon rubber. The cloth is made of threads. The threads are made of nylon. It is woven into a cloth, often with other materials used as "ripstop" fibers or a simple heavier thread. The treatment is then spread lightly over the cloth, often by rollers and/or knives, where it penetrates the the threads and gaps caused by weaving leaving a thin film to waterproof it, incidently making it hydrophobic and slippery while reducing the texture of the woven cloth. Properties we exploit in rain for excellent waterproofing. A more conceptual view of silnylon would be a silicone film, reinforced with nylon cloth.

Cuben is made by taking two(or more) layers of waterproof plastic and sandwitching them over a reinforcing fiber, often spectra, kevlar and carbon. These are pressed togther under very high pressures until they actually bond. It is stiffer than a woven cloth and doesn't have the streatch. Conceptually you can view this as a plastic film reinforced with threads.

The difference between the two, because of the actual construction methods, becomes very large.
Attacment of multiple pieces or loops.
Sewing:
A thread through cuben will elongate a hole till it anchores on a fiber because fibers are sparsely interspersed. This also means one or two can tear before a couple others can bind up together supplying the stopping power. So, holes get larger when sewn, especially under heavy loads. A thread sewn through silnylon has a high density fabric that "catches" slippage. It will stretch, elongating a hole, but much less than cuben.
Adhesives:
To avoid this problem adhesives are used. These have different rates of stretch than the plastic used in cuben. Under load, it will crack, potentially leaking. It can create a stiff seam that can crack, too. So, a non drying adhesive, like a tape adhesive, is used. But this can creep under loads. So, simply stitching it and bonding it produces a joint with the best characteristics of both, simultaneously reinforcing the worst characteristics of both types of joins.
On silnylon, reinforcement is not usually needed. But this brings up an interesting side point. Seam sealing, usually done with a thinned silicone adhesive on silnylon, and often done new, is not as effective as *after* holes have already stretched open and fibers have moved, slightly.

Repeated loading, such as with a tarp, will give different results, also. Cuben is, for all intents and purposes, a plastic film. It can stretch permanently under load. Eventually it will fail, but more importantly, it will fail if scratched. A good example is thin plastic tarp. It is quite strong untill a scratch, nick or other defect is made in it. Then it tears quite easily. It is almost impossible to avoid all abrasion while camping. So, unless you use heavier weight cubens (multiple layers,) small holes/leaks, or "slices" may appear. These are not easy to repair with cuben. Patching rather than sewing is prefered, duct tape is good for that. Wind hammer can cause increased streatching. A not quite perfect pitch and leave flapping, causing "impact pressures" that exceede the material's normal strength.

Silnylon, while not subject to surface abrasion, *is* subject to stretching. Fibers in the cloth can become displaced opening previosly sealed seams, pole points (often reinforced,) loop tieouts, and, the fabric itself. This can continue to extremes. Example: My tarp, a 9'x11' silnylon has about 3" of stretched material near the center from constantly loading it over a hiking stick. Loosened coating is broken, tiny, inconsequential leaks now leak through, etc. Inside, it is easy to see where it is stretched and where it is not with a good light behind the tarp. This can be repaired (and has been twice) with a layer of silicone/mineral spirits over it. Normally, impact pressures are more distributed, causing little extra stretch.

So, while both are strong, general durability for silnylon is greater, if only because of the *way* the two are made. If you are seeking UL weights, you expect decreased durability, soo, this isn't usually a problem. This is a philosophical difference, subject to interpretation. I do not recommend one over the other.

I hope this helps!

[David Ure]

Excellent information James! YOU should be writing for BPL.

[Jeffs Eleven]

Yeah, what the Hell?? That essay is amazing.

[James Marco]

Sorry, I can't even spell….

[Mal Hooper]

The silnylon version is like dynamic climbing rope. The cuben version is like Dyneema webbing. Both are absolutely awesome at their intended task so neither is "better", but their tasks don't overlap. It is just my opinion, but the cuben version of the Trailstar loses its best feature which is versatility.

Shelters that have one basic pitch configuration like the *mids and A-frame cat tarps are great in cuben.

I hope to one day have a sil Trailstar and cuben Grace tarp.

[James holden]

i thought all shelters had the same basic purpose … keep you dry and out of the wind ;)

as to which? … who knows, its yr moolah!

[john hansford]

Have a look here :

http://www.christownsendoutdoors.com/2012/03/trailstar-wars.html

[Peter Atkinson]

Thank you all – that has been ace information! It seems like for this shelter Silnylon is the easiest to pitch and most flexible to use in terms of pitch options, so that is where my choice will be!

Pete

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