I’m usually a pretty serious advocate of buying brand name gear when your life depends on it. Recently, however, I’ve needed things that are so specific for what I am doing that they simply aren’t marketable. Last year, I made gear to allow me to safely paddle a kayak from Key West to The Tortugas which required a sail, cockpit cover, sea anchor, and outriggers among other things (click the links to see the designs). But recently, I’ve set my eye on a backpacking trip necessitating the lightest gear and have been seriously disappointed with the options currently on the market. I was very impressed with the light weight and affordability of my 7 ounce silnylon Integral Designs Siltarp 1 that I purchased last year. But I figured using a similar rectangle design with Cuben fiber instead of silnylon could drop that weight even further. I did some calculations and figured I could make a Cuben fiber tarp using ZPacks materials that weighed just 2 ounces.
So I ordered
- Four linear yards of their .34 oz/sqyd fabric
- Four strips of .51 oz/sqyd 1″ seam tape
- One 6″circular adhesive reinforcement
- Two 2.5″ X 2.5″ stick on loops
- I also had some small grommets lying around from a previous project.
I first cut the fabric into a 54″ X 82″ sheet. In hindsight, I probably would have accepted another .1 ounces to make it 90″ long. But being 5’6″ fortunately allows me to carry a pretty small tarp. I then cut the 1″ tape in half, giving me two strips of 1/2″ tape. I lined every edge with this 1/2″ tape rolled over to prevent fraying on the edges.
After that I cut the circular reinforcement into fourths, and applied one of those to each corner. I decided to just apply to one side, figuring, despite being aesthetically less pleasing, it would definitely be the strongest part of the whole tarp.
After that I added 1-gram grommets as close as I felt comfortable with to the edges. I didn’t want the edges to roll over with the grommet too centered and I didn’t want the grommet to rip out if it were too close to the edge. For the guylines I used G-Line 1 Polyester Dyneema Guyline Cord from Litetrail but it is apparently no longer available. The ZPacks 1.25mm Spectra cord will work just as well. I used ~1.5 meters per corner and ~2 meters for the ends. The plan is to have long guylines so I can tie the tarp between trees more often than not. That’ll give it more functional surface area and allow my only carrying two stakes to be much more practical. It ends up being ~10 grams of guyline cord.
I put the stick on loops centrally on the short sides to allow me to run a guyline through it and set up the tarp A-frame style using trekking poles. I’m switching to the collapsible Black Diamond Ultra distance trekking poles which doesn’t allow me to simply take the guyline through the hand loop on the trekking pole like I did before with my adjustable poles. What I’ll probably end up doing is using two more stick on loops at the correct height on my new poles and just running the guyline through there.
The tarp ended up looking great. I managed to keep straight lines despite having less than ideal tools. I highly recommend using a rotary cutter to cut the fabric. Other than that there is no sewing involved and it takes just a few hours to make the whole tarp. It ends up costing ~$100, surprisingly high for a DIY project but still markedly less than a similar retail tarp.
While the length is easily adjusted simply by cutting the fabric longer, increasing the width would need double sided tape. While still stitch free, it would certainly add to the weight and possibly the fragility by adding another point of failure.
Comparison to retail tarps (all weights are body, guylines, and 2 MSR carbon stakes):
Mine 3.1oz $100
Zpacks 5.15oz $185
Hyperlite tarp 7.1oz $300
Mountain Laurel Designs Grace Tarp 5.5oz $285
If you’re not interested in making your own tarp, Zpacks is definitely the way to go. They normally make their rectangular Cuben fiber tarps out of the heavier .51 oz material but they very likely would make one out of the lighter .34 oz material if you request it.
I hope this helps someone else interested in making a ridiculously lightweight tarp but at least at minimum it proves it can be done. Up next: ridiculously lightweight Cuben fiber rain jacket.
I made a new tarp and used Zpacks stick on loop for the corners instead of grommets. I also didn’t use tape reinforcement for the edges. Both of these adjustments make the tarp even easier to make, lighter, and I believe with the same durability.