21 responses

  1. John B. Abela
    November 23, 2012

    I have been hearing a LOT about David over the last month or so!

    Being pretty much a 99% of the time esbit hiker none of this stoves appeal to me, but I gotta say every time I see that polycro shelter I shudder and tremble inside. I do not know if its because I am not willing to trust a shelter made of polycro, or that somebody out there has actually made a potentially viable shelter out of polyolefin – and that just seems freaking awesome!! As one of the few people in the world that have over 500+ miles of hiking with a 0.34 cuben fiber shelter (mine is 80.24 grams / 2.83 ounces) I have come to learn that this light of material presents some very serious risks. In many ways it seems like polycro might even be pushing those risks even further. Would love to hear your thoughts on this one Philip (and David if you ever read this.)

    • Earlylite
      November 23, 2012

      What ‘risks’ do you mean John?

    • David Gardner
      November 25, 2012

      Hey John, thanks for the comments.

      Please note that my stove system is made to work with Esbits too. The alcohol burner is replaced with an Esbit burner, and stakes are put through holes in the side of the windscreen to support the pot at the optimal height over the burner. My Esbit system will boil 500 ml of 70* water in less than 7 minutes using 1 fuel tablet. The stainless version weighs 54 grams (45 if you skip the base sheet), and the titanium version weighs 44 grams (36 if you skip the base sheet). For comparison, the stock Esbit brand stove weighs 88 grams and takes 8 minutes to boil 500 ml. These times are under lab conditions, and in the real world my system is far less susceptible to wind.

      Regarding the tarps, I think that all ultralight and super-ultralight equipment involves some trade offs of durability vs. weight. I have not tested my tarps under winter storm conditions yet, so I don’t know the limits of their durability. But I have used them in winds of 15-25 mph with no failures. All that being said, my intuition is that polycryo of the thicknesses currently available may be best suited to 3-season use. If I can find a source of material approximately twice as thick I intend to make a pyramid tarp and test it for ski camping, and see how it does under snow loads.

      Not quite sure exactly what kind of risks you are thinking of, but I assume it is something like a tarp tearing in the wind and not being useable. I include a yard of ripstop nylon sail repair tape with each tarp, hopefully to catch tears while they are small. But assuming a worst-case scenario of complete tarp failure, my solution is that I use sleeping bags with Gore-tex or other DWR shells instead of quilts, and carry a mylar “space blanket” bivvy (53 grams) in my “10 Essentials” emergency kit (which I always pack regardless of whether I am using a tent, tarp or nothing) so I have a dry survival cocoon even without a tarp.

  2. Michael
    November 23, 2012

    Interesting to see David doesn’t bother to “hem” the edges on his tarp. That would be one “risk” as many have claimed polycryo tears. It will puncture easier than cuben, but that isn’t an issue to me. I figure if a branch falls on my tarp, I’m in enough trouble as it is. I have not had mine in serious storms yet, but would not have a problem in at least 40 mph winds.

    You can see what others and myself have done at http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=59450

    I assume his weights include all lines & stakes as it is much heavier than my 6×9.

    • David Gardner
      November 25, 2012

      Hi Michael. Your tarp as shown on BPL was one of my inspirations.

      Actually, I guess it doesn’t show in the pictures, but my tarps are “hemmed” at the ends with the double-sided tape that comes with the kits, although not along the side edges. I did it that way because the greatest stresses seemed to me to be at the ends, where the tie-outs are pulling in two directions on the material. But even though I haven’t had any failures along the side edges yet, it probably makes sense to “hem” them anyway. For sure it is stronger.

      My weights include poles (because I don’t hike with trekking poles), all cords, and 10 stakes (two aluminum Nanos at the ends of the ridge cords, 8 titanium shepherd’s hooks for the sides). I am experimenting with reducing the size of the tape gussets to shave a few more grams off, but I like how the bigger gussets spread out the stresses on the polycryo and and reduce the “risk” of tears. How much does your 6 x 9 weigh?

      • Michael
        November 25, 2012

        Mine weighs 6.1 oz, fully hemmed and taped and with a variety of attached guys that aren’t too long. I know I could reduce it some but I haven’t gotten to use it much yet. The 3M 2120 transparent duct tape is relatively heavy so I try to minimize that, cutting the roll in half so it’s 15/16″ wide.

        I suspect your tape is pretty heavy as well. It looks like you use significantly more than I do. My typical corner piece is 8″ long which gets folded over top and bottom side of material, becoming 4″ effectively, and then I use a piece on the top perpendicular to that to spread the force.

      • David Gardner
        November 25, 2012

        I see you use trekking poles for your tarp. Since I don’t use them I include two carbon fiber poles, which is 4 oz of the stated weights. Does your 6.1 oz include stakes?

        I have used more tape than you did, especially on the pictured “Tres” tarp which has a full-length piece along the ridge line to join 2 sheets of polycryo. Based on your experience I will try reducing the length of my tape pieces at the corners and sides, especially after I hem the side edges. You could probably reduce your weight by using ripstop nylon sail repair tape, which is very light compared to duct tape and especially Gorilla tape. Check out http://www.sailmakerssupply.com. They also make some very sexy Kevlar sail repair tape, but it is wicked expensive.

        I forgot to mention before that I also use a small loop of shock cord at each of the tie-outs. It’s heavier than the Kevlar cords, but it keeps the tarp pitched taut and also permits some “give” in windy conditions to reduce stress on the membrane and reduce the risk of tears.

      • Michael
        November 26, 2012

        No stakes in my 6.1 since they are so variable. I highly agree about the shock cord, too.

        Thanks for the tape tip. Do you know if their shipping is reasonable for just a single roll?

      • David Gardner
        November 26, 2012

        A 25′ roll of the ripstop nylon tape costs $7.47. Shipping via USPS priority mail to my zip code is $6.95.

        Shipping cost for 2 rolls is the same.

        Shipping cost for 3 rolls is $9.50.

      • David Gardner
        December 15, 2012

        Hey Michael,

        Just made a 7′ x 9′ solo tarp from a single sheet of polycryo. Fully “hemmed” with the included doube-sided tape, ripstop nylon sail repair tape for the side tie-outs, Kevlar sail repair tape for the ridge line tie-outs, and 300 lb.-rated Kevlar cord for the ridge line. I also used nylon washers to reinforce the tie-out holes.

        Weight = 5.4 oz.

        10 shock cords for the tie-outs and 40′ of the 300 lb. Kevlar cord adds 1.1 oz.

        2 carbon-fiber poles adds 3.3 oz.

        8 titanium stakes and 2 Nano stakes adds 2.5 oz.

        Total weight of complete system = 12.3 oz

        Gonna pitch it in the rain tomorrow and take some pictures.

        Thanks for the inspiration and ideas.

        David

      • Michael
        December 16, 2012

        Sounds nice, David! I’m curious why you use different tapes for the tieouts? I had done that as well with my original design but went to just the weaker one with my second that was made from polycryo as the extra strength really wasn’t needed. I assume the Kevlar tape is stronger and heavier, but I would not expect the ridgeline tieouts to take significantly more force than the corners.

      • David Gardner
        December 16, 2012

        I used the Kevlar tape for two reasons. First, I had a roll that I wanted to try out and see how it would perform. For the two places where I used it, the difference between the Kevlar tape and the ripstop nylon tape is only a couple of grams. Second, my experience is that the ridge line tie-outs take significantly more force than the corners and sides. I have measured the ridge line force at approximately 20 lbs., and the corner force at 10 lbs. So, even though I’ve had no problems with the ripstop nylon tape at the ridge line, I figured stronger was probably better. And it just looks cool because it’s mostly transparent and you can see the Kevlar threads embedded in it.

        That being said, my tarp has a ridge line cord of 300 lb. Kevlar cord between the two nylon washer reinforcements at the ridge line tie-outs, which takes most of the force anyway. Plus, it appears that the Kevlar tape’s adhesion is not as good. So I will use ripstop nylon tape for the ridge line tie-outs on production models.

        I have posted some pictures to my web site and Facebook page.

  3. Grandpa
    November 26, 2012

    How does the polycryo hold up in cold weather for tarp use? The reason I ask is I use a polycryo ground cover for my Tarpten and one time my grandson and I were camped on top of a saddle in below freezing temps with 50-60 MPH winds and a section of my ground cloth broke off when we were trying to pitch the tent. It seemed to have gotten brittle in those conditions. Other than that incident, I’ve been pretty impressed with the material.

    • Michael
      November 26, 2012

      My guess is you got a bad one, seeing as it is used to insulate windows from drafts during winter. It would be pretty pointless to become brittle in the cold for that application.

    • David Gardner
      November 27, 2012

      The source I get my polycryo from has two types of the material. One is rated for indoor use, the other is rated for outdoor use. Perhaps you got the “indoor” variety, which I presume is less tolerant of very cold temperatures. If you got the “outdoor” type I would be totally surprised it failed unless it was a bad batch, since it is specifically designed for outdoor exposure to very low temperatures.

  4. Grandpa
    November 26, 2012

    That was supposed to be “Tarptent”. I guess I either went ultralight on the spelling or a piece of the name broke off and blew away along with the portion of polycryo ground cover.

  5. Grandpa
    November 27, 2012

    Thank you for the info. I’ve often wondered about using polycryo for a tarp but after that piece failed, I thought it wouldn’t be strong enough. Now I know differently. Your products intrigue me.

  6. Hoboken Chalupa
    December 1, 2012

    Being completely honest, I’m not an UL hiker, or even an SUL hiker but in glancing over these products I was excited to see some fantastic design features and ingenuity regarding the use of new lightweight materials. Grats Dave! … And thanks Phil for opening the dialogue.

    I’m definitely interested in seeing the website to find out if you’re retailing a poncho or pack cover as well; or tarp/poncho idea similar to ExPed.

    (By the way Phil , I plan on commenting on your “Walking Meditation” post. I couldn’t agree more with you and that post certainly deserves some more feedback.)

    ~ Chris

    • Earlylite
      December 1, 2012

      Thanks Chris – seems we are kindred spirits. I was also inspired and excited by David’s out of the box approach.

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