Last summer I bought my first piece of Cuben Fiber, a ZPacks Blast Food Bag. Having never owned any Cuben Fiber gear, I just wanted to see what the stuff was like in person, rather than reading about it online. My end goal was to see if I wanted to try a shelter or tarp made of Cuben Fiber, which I’d been hoping to try for quite some time. My only real reservations were durability, since I’ve never met anyone with the lightest fabric for tents, and cost, since Cuben tents and tarps can be extremely pricey. The food bag from ZPacks is less than $30, so that seemed like a good investment. Judging by how many ZPacks Blast Food Bags I saw on the Appalachian Trail last month, it seems like almost every other hiker out there went this route as well.
This summer, a friend ordered some discounted Cuben Fiber from eBay and built a tarp for me to test out on the trail (named The Lupus, after his dog). That gave me even more time to observe the material in action, and I must say I’m nicely impressed with it.
First, the reasons I wanted to switch from a silnylon shelter (which I’ve been using for the past 8 years) to a Cuben Fiber shelter. Weight is actually not a part of the equation for me. Let me say that again, though, just to get that straight: even though a tarp with the same construction as my silnylon one would weigh about half as much in Cuben, that’s not at all why I wanted to upgrade.
Here are the reasons:
No Seam Sealing: Cuben Fiber sheets are glued together with an ultra-strong tape/glue rather than sewn. Sewn seams on silnylon leak over time, and silicone seam sealers break down over time. This was a problem for me on the Pacific Crest Trail, and has started to be a problem with my silnylon tarp. I’d rather never deal with seam sealing.
No Stretch: Silnylon is a stretchy material, which is actually kind of nice when trying to pitch the tarp very tightly. But the problem is that when the material gets cold, it stretches on its own, which means the nice, tight tent you pitched in the evening turns into a sagging, flapping mess when the temperature drops at night and the rain starts. Cuben Fiber has no stretch whatsoever, so the tight pitch stays tight.
Newer Construction: Okay, this isn’t actually a feature of Cuben Fiber, but I’ve been looking to get a new shelter to replace my trusty old tarp because I wanted newer features like Linelocks for better adjustments of guylines, a shaped tarp for more efficient set up, and catenary ridge line for a tighter pitch. I figured if I was going to get a new shelter, I might as well go with all the features I wanted.
The issue of durability, which is the major concern for most people, should be entirely laid to rest. The Blast Food Bag uses a very thick grade of Cuben (1.4 ounce/square yard) for maximum durability, and since the small bag doesn’t need to be incredibly light. The Lupus uses the lightest grade (0.5 oz/yd), the same that ZPacks uses for their shelters. The Lupus stood up to heavy winds without any issues with damage. I’m sure if a tree fell on it, there might be some issues, but then again I can think of more problems than the tent getting damaged in that case. After 8 years of using my silnylon tarp, there is no damage to that tarp, either, and the 0.5 ounce Cuben feels just as durable as the silnylon. If that doesn’t convince you, I’m a big fan of this video by Joe of ZPacks, demonstrating the puncture and tear resistance of silnylon and Cuben.
The Lupus, since it was Steve’s first attempt at making anything out of Cuben, isn’t a perfect shelter (I ended up reinforcing the tie-out loops by sewing them, which negates some of the benefit of the glued seams, but the major seams are still only glued), but it has been a wonderful experiment. It saved me almost $200 (the price of a similarly sized tarp from ZPacks) and has given me plenty of food for thought. In the future, I may pony up the high price of a professionally made Cuben shelter, either a larger tarp from Gossamer Gear, a tarp-tent like the Hexamid from ZPacks, or a Duomid from Mountain Laurel Designs. For now, though, I’m pretty happy with my Lupus tarp, which is likely to replace my old Silnylon Scout for general 3-season use.