Make Your Own Gear: Five Yards to SuperUltraLight
Part 3, Tarp

I would not suggest using velcro as it can be fussy and annoying, at least in my opinion. check out the bug bivy from mld if you havent seen it already. There are quite a few out there and if you just follow a design you like or make up your own you should do all right. I would go with nanoseeum netting and silnylon floor. corners could connect to the two ends of the tarp and the corners. good luck.

I'm extremely happy with my tarp . . .
There are a few things that I learned, or experienced which may help someone else.

I don't have a tally for the time spent on it, since it was constructed over the winter/spring and various weekends, but the time was MUCH MORE than listed in the article.

My biggest deviation from the original design was length. I added 10", based on comments by other users and a couple of scale mock ups that I constructed with paper. Some graph paper & tape makes this an easy task.

I did not change any other dimension. The finished tarp and bag weight was 7.0 oz. I have not weighed it with the guylines & tensioners yet.

I used the catenary curve .xls mentioned in this thread. I'm sure that I documented my settings, but I can't find them right now to report what I used. I think I was in the 400/500 range and I believe I used 110 for the ridgeline.

My first test of the tarp was on Santa Rosa Island. The island is known to be windy and I wanted to test how it would function in high winds. Since I had finished it days before the trip and hadn't set it up yet, I struggled in the wind. The biggest problem was getting it set up both low enough to the ground for the wind and high enough to get in.

I used Triptease coupled with a 1/8" reflective shock cord looped to create tensioners on the 6 non-pole guyline locations.

A NOTE ABOUT SET UP: I've now learned using the following method is easiest: 1. Stake the low end corners. 2. Set & stake the high end poles & then corners. 3. Return to the low end to stake the pole. 4. Adjust all the corners. 5. Stake the sides. 6. Adjust as needed.

I tried and tried to adjust the height of the "high end" so that it was high enough off the ground for me to get in. The problem was that the height of my goat poles was not enough to raise the end when placed as far away from the tarp as needed to outstretch the beak.

A friend in the group insisted that the poles should be on the inside. I disagreed, but relented mostly because I'd just read a thread about someone wanting to set it up like this.

In the end, the "high side" was too low to enter through but the "low side" had enough space to snake under, past the pole. Again, the wind played a factor in how low the tarp sat. Here's a picture of the tarp next to a Granite Gear tarp and a Sierra Designs tent during one of the wind storms:

I had expected the tarp to be loud in the winds, but with a taught pitch, it was MUCH quieter than either of the other two shelters. I was able to fit 2 people under the shelter and some gear.

PROBLEMS & RESOLUTIONS:
1. PROBLEM: During the windiest night (3rd night), the low end pole tore the re-inforcement patch.
RESOLUTION: During seam sealing, I used the mineral spirits solution to coat the tarp and the torn patch, I then cut and sewed another patch out of spinnaker and just sewed it over the other. I don't plan on putting a pole inside the low end again. I am using a clove hitch on the end of my pole tip and the pole outside the tarp.

2. PROBLEM: Not able to raise the high end high enough to enter the tarp without slithering on my belly. Also, the high end wasn't very high.
RESOLUTION: I created a patch out of a low weight denier PU fabric that I had purchased to re-inforce the storm seal of the mountain poncho. The patch has been sewn to the interior of the tarp and allows me to pitch the tarp using my trekking pole on the inside, allowing for a much higher pitch.

Looks great! My pole goes on the inside on the high end as well after seeing sam's tarp. I stuck with the stock dimensions and no catenary… I didn't have time to mess with it, since I had to get it and my bivy done in less than 4 days for a trip. I kind of wish I would of extended the ridge line more than the 3 inches I did, but I was having fun trying to figure out how I was going to get 2 full size beaks as well. I do now have all the fabric cutout to make the backpack as well though. So this fall if I have a possible project lined up.

I made a yellow silnylon version of this tarp, but made a few changes to it (270 cm long, 200 cm wide front, 160 cm wide back). It was my second MYOG project, and it was a lot of fun, the end result weighing in at 448 g. I wasn't yet able to go out and pitch the tarp (its -22°C and the ground is frozen rock solid) but I will have a try tomorrow and post then some photos of the pitched tarp. For photos of the work in progress and detail shots of the finished tarp, have a look here.

Sam, I usually don't like to re-animate dead threads, but this is a great article and I felt I needed to share my efforts here and let Jay & others know. I think its one of the most influential articles on BPL, and surely has animated many to try out MYOG. Anyhow. Here two photos of the tarp pitched on the snow, some more here.

*sharalds: edited photo width *

I've always felt that if a topic is relevant than it's never "dead" so no worries in posting relevant material to a thread.

Timo, your design will certainly work well – there is some added benefit of the shaped beaks in Jay's original design though as they help keep rain out of the tarp excellently.

Jim, thanks for the photo. I've been looking for a way to better tension a tarp beak.

I downloaded the spreadsheet and added rows to compute the difference between a catenary and a circle that intersects the midpoint and the ends of the catenary. For anything you're likely to make, the difference is negligible.

For example, cantenary and circle for an 8 foot ridge line with a 4 inch bow will differ by 0.07" or about a sixteenth of an inch. You're not likely to sew to that tolerance and a circle is easy to construct. A string and sharpie marker compass, a helper and a big floor like a gym or garage and a little trial and error is all you need.

If you'd like to try the circle method described above and have the space necessary, here's a table of radii for various lengths and 'bow'.

-Lance

Nice job

You are now addicted to MYOG, too bad…

Many thanks! MYOG is definitely addictive. It's also time consuming (but in a good way), so I'll probably hold off on too much more until the winter (unless I can get my wife to consider sleeping in a bivy).

The ridgeline length is 90" with a 3" deflection on the catenary curve. The curve turned out really nicely, with almost no folding along the seam. I believe the rear panel tapers to 35" (instead of 33"–I mismeasured and just figured it was fine). Other than that, all of the dimensions should be true to Jay's article.

Nice spot on the Ironwire too. I used 3/8" webbing with Line Loc 3s for the tie-outs (also picked up from Lawson). Originally, I was going to use ZPacks' thinnest Z-Line, but after working with it, it was just a little more difficult to use than the Ironwire. So, for the tenth of an ounce or so, I decided the thicker (2mm) line was worth it. For the same reasons, I ended up using the Line Locs too.

I hope you get to use the LH Solo soon. It looks like a great tent. My wife and I almost bought a SoLong 6, and Judy was great to work with. Right before we pulled the trigger, we ended up moving to Montana and I realized we would need something that could handle snow loading better. We weren't too far from you though, just across the border in East Texas.

I forgot to mention above that my wife actually made the bivy (I posted about it over here) as a belated Valentine's Day gift (I wasn't going to use it until this spring anyway–so I didn't mind the delay). I had her sit under the tarp with me yesterday, and she said that she actually might consider trying out a bivy under it.

Normally we use a Rainbow for the two of us–the tight quarters make it nice and warm. But I would love to see if I could get her tarp camping with me!

Very nice article! It has been a great help as I get started making gear.

A general note to the newbies (like me): make sure the fabric you get is, in fact, 54+ inches wide! I got mine and it was too short :( It's going to end up a regular 8 x 10 tarp.

A few helpful hints for future articles. 1. Please make the pics larger (or clickable). 2. please use contrasting thread so it's easier for the reader to see exactly what's going on. 3. Please give hints on how make long straight pattern marks on a really slippery material (my ripstop has a lot smaller grid that is almost impossible to follow).

Again, thanks a bunch. This article has already made my membership worth it and I'm looking forward to more!