Caternary Cut Cuben Fiber Poncho Tarp

Keith,
Are you talking about a MYOG project or if anyone is selling a Caternary Cut Tarp made out of Cuben Fiber?

I’m clueless when it comes to MYOG- I’m thinking of one that I could purchase.

Have you looked at what is being
sold here at backpackinglight.com?

Yeah- it looks great, but… I’m hoping to go with a poncho/tarp set-up that can do double duty as rain gear rather than just as shelter. I’m not sure if cuben fiber can handle poncho use but it sounds stronger than the spinnaker stuff and lighter too.

You see the tarp/poncho I am standing next to in my little picture? That is Cuben Fiber. It is about 48″ by 80″ more or less. I don’t remember for sure.

It works great as a poncho but is on the small side as a tarp. The weight with guy lines and Ti stakes is under 5 ounces. The poncho alone is a little less than 2 ounces. Their is a thread in the MYOG forum about making it.

Mountain Laurel Designs makes a silnylon catenary cut poncho tarp, but not cuben. They say that the small sizes on the cuben tarp don’t require a catenary ridgeline.

For the past two or three years I’ve used an Integral Designs poncho-tarp (5×8 silnylon). It worked great as a tarp, I don’t think one could expect more from a small tarp in terms of performance. When used right it will stand up to some VERY nasty weather. In terms of aesthetics…the hood is right in the center and makes for a very ugly ridgline. As rain gear it was great, I’ve worn it while being battered with 35-40mph wind driven rain and it kept me (and my pack) dry. The hard part is staying dry when breaking or setting up camp in such weather…it’s just not gonna happen.

I have decided to stop using it as my primary shelter though, and instead only use it as shelter on short, fair weather trips. It will still be used as my rain gear though…I’m sold on ponchos. Instead I plan on using a Tarptent Contrail. I’ve decided to switch over because you tend to get wet and stay wet (and often get cold) when you set up camp or break it down, as you must take off the pocho and be exposed to the rain in order to pitch it as a tarp. In addition, I used it in combination with a breathable bivy (BMW Vapr bivy) for wind and rain spray protection, but I would always get condensation in the bivy no matter what the weather conditions. That is actually my primary reason for switching from poncho to tarptent, but it is not the fault of the poncho of course.

Bill, I’m this close to following your lead again and making a poncho/tarp/hammock canopy. I have my Cuben samples and some ideas. The strength of the Cuben does not concern me, it is amazing stuff. I’m looking at the same fabric weight you’re using. The puncture resistance in poncho mode gives me some pause, as does the initial cost of the minimum order. I did some puncture tests on my samples but it’s hard to correlate that to real use. Am I worrying too much?

p.s. I picked up an Xtreme stove at an REI garage sale for $10. I’m about to start modifying it. I think this makes me a groupy. :)

Dane, I think MDL makes one out of Cuben as well. Though it will be some time before you can order from them. It’s interesting to hear your experience, as I am heading to where your leaving. I have no experience yet, but was hoping than my hooded wind shirt would suffice when going from shelter to poncho mode. I also carry one of those 2oz, $1 plastic ponchos.

I know that MLD makes a cuben fiber poncho tarp, but their description does not include a catenary ridgeline. Are you saying it’s in the works?

Hi All,
When we reopen in about a month+ or so we will offer a wider range of Cuben products than anywhere else. In general, the stretchier and larger the material/tarp/poncho is, the greater the advantage to a cat cut and we use different ones in each product size and fabric. So a very small Cuben poncho does not benefit much, IMHO, from one. The Cuben roll widths at only 48″, add an edge and a ridgeline and the size shrinks pretty small. The answer may be to just use double the fabric and charge a lot more as the cutoffs would be too small for much more than stuffscks and even then the cutoff stack would always be growing adding waste/cost. At about $20 per yd fabric cost, you can see how a wider one at 8.5 or 9′ long (that would benefit more from a slight cat cut) would quickly get close to $120 in materials alone. Add all the labor and overhead and would folks pay over $200 for full size / full featured Pro poncho? You tell me. So, maybe the simpler 46″ X 8.5′ no seam/ridgeline hole in the middle design may be the only commercialy viable one possible as long as the material is so expensive. I’d love to hear options/ideas.

Hey Ron,
You guys are awesome!
One idea to be able to add a little more width to the ponch0-tarp would be to add a cat cut along the sides by sewing it on as an addition. Sure you would have seam a few inches off the ground but it would not hinder the performance of it, (especially if they were taped seams). You would be able to add about 3″ to the width on each side plus an addition 3″ with the cat cut, (makes for an addition 6″ on each side). After you take off about 1 1/2″ for both seams, you would end up with a piece about 58 1/2″ wide.

Hi,

I’d have to calculate the labor costs involved with addtional seems vs just using another whole width of material…

Thanks for the ideas.

Ron,

Not challenging you on this, just looking to understand the factors at play (you’re in the business, I’m not).

With 48″ stock an approximately 4×8 poncho tarp might require more or less 3 yds of stock (including material for the hood)

What are the factors working against building a 5×8 panel with a seam running the short way. 4 yards of stock would seem to be enough for that with a hood.

BTW, it’s just plain fun watching what you folks come up with.

Jim, I’d worry about a tarp designed with the main seam running perpendicular to the ridgeline and accompanying stresses. It would also make a cat curve on the ridgeline more difficult, necessitating another, less necessary seam (if we still care about the cat ridgeline).

My concern would be compounded with a cuben tarp, since I seem to remember reading that seam creep is a greater problem with thin nonwovens. I do, however, like the idea of adding material toward the outer hem – if an economical way to do this could be devised, Ron would have a real winner, IMHO.