GEAR: Cuben Fiber Tarp Poncho
WEIGHT: 7.9 ounces including stakes
DIMENSIONS: 54″ x 108″ (1.5 yds x 3 yds)
COST TO MAKE: ~$200
WILL I USE IT?: I have and I will continue to. So far used in VT and WA. I will continue to use it on my solo ultralight adventures.
I needed a shelter for my Long Trail thru hike, so why not make a bomber super ultralight shelter/poncho to save as much weight as possible?
Instead of carrying my 7 oz rain jacket – which is great and very light and waterproof (the Patagonia M10) PLUS a 1 lb+ shelter, I can carry my tarp/poncho which weighs in at 7.9 oz INCLUDING stakes. Plus, it kind of looks like an octopus suit – with a opaque blue hooded portion and translucent body – which, let’s face it, is awesome.
I wanted an absurdly ultralight shelter that I could use to sleep under and use as waterproof breathable rain gear while hiking. There are a few products on the market that are similar (e.g., Zpacks Micro Ground sheet $175 – a ground sheet not shelter mind you, MLD Cuben Fiber Poncho $175 – no breathable portion, Six Moon Designs Gatewood Cape $110 – silnylon).
The tarp/poncho was made using 0.51 oz/sqyd cuben fiber (tarp body), 1.62 oz/sqyd “Challenger” Waterproof Breathable Cuben Fiber-eVent (breathable hood/chest), 1.0 oz/sqyd cuben fiber (tie outs), D-rings and mittenhooks (removable tie out hardwear), zline 1.25 mm spectra cord and micro line loc guy line adjusters (guy lines), single sided cuben fiber tape and double sided cuben fiber tape (reinforcement), and titanium ultralight tent stakes.
I drew up the layout and made tests using Tyvek. I cut a large hole in the 0.5 cuben for the breathable portion and hood. The waterproof breathable portion was designed to allow heat and moisture escape the body of the poncho around the chest, head, and neck while hiking hard and exerting maximum energy. I made the hood using Challenger waterproof breathable cuben fiber eVent fabric, taped seams, and added drawcord and cord lock then fitted fitted the two pieces (tarp and poncho) together – adhered with double sided cuben tape, sewn with polyester thread, and taped with single sided cuben tape for waterproofing.
I designed the tie outs for maximum strength and durability. Much thought went into optimum design in order to minimize stress and strain in one seamless, edgeless single piece of cuben fiber. I wanted to avoid several pieces of fabric which would compromise the cuben strength by breaking the long strands of dyneema thread. I also wanted to avoid sharp edges and corners which could create weak spots in the piece. The tie outs were laser cut for seamlessness and cut with rounded edges to minimize strain. The tarp corner is sandwiched between two offset layers of cuben on either side. Tie outs are adhered to tarp corners and edges with double sided cuben tape and reinforced with polyester stitching. Ideally the tie outs would be adhered rather than taped, however, due to adhesion difficulties I opted to adhere with strong double sided cuben tape instead. I incorporated D-rings for guy line removability. Guy lines clip to D rings on tie outs with mitten hooks.
How does it perform? Perfectly!
The tarp is just big enough to fit 5’2″ me underneath on my Thermarest and sleeping bag. So, it’s cozy. But it works like a charm. Thus far I have used the tarp on camping adventures in the Washington Enchantments and on the Vermont Long Trail.
I used the tarp as shelter in soaking, humid Vermont rain and amazingly stayed dry. I cinched the hood closed and had no problems with water dripping in. Backsplash was surprizingly minimal, considering the tarp does not come all the way to the ground but instead leaves a several-inch gap (bigger at the head tapering to the feet). I also used an ultralight umbrella over the front opening of the a-frame for added rain protection, which I would continue in future rains, particularly in windy rainy conditions. The breathable eVent portion seemed to allow more moisture through the fabric pores which left the surface of the center of my sleeping bag damp after 8-10 hours overnight in steady rain – which I noticed but did not affect the sleeping bag performance even with the high humidy/inability of anything to dry. This is not a deal breaker, but something to keep in mind especially in cold and rainy conditions.
When used as a poncho, it also works great. The poncho is big enough to go over and around my pack, and longer in front so when walking through wet brush and overgrown trail I stay dry. I wore the poncho in Vermont rains and stayed dry when possible (however, I also got wet in sideways wind and driving rain, but I’d expect to get wet in any rain jacket in those conditions). The waterproof breathable portion kept me from overheating and oversweating. Also as a plus I don’t have to worry about rain pants because the poncho covers my legs or about a pack cover because the poncho goes around my pack.
Overall: the Cuben Fiber Tarp/Poncho is an excellent piece of minimalist lightweight gear. The design and production went great. It performs well as both a tarp and a poncho (and pack cover!). And there are so many ounces of savings. A resounding success.