First Build, Winter Super Tarp, Lots of Questions!

[Wolfman]

I just order 15 Yards of MEMBRANE silpoly in Khaki from Ripstopbytheroll.com along with everything else I will need to build this tarp. (at least I hope!)

I have many questions and I am sure I will have more as I build the tarp so all of you experienced DIY please be patient with me.

This is my basic plan.
Tarp Design.pdf

It is a BIG tarp, 12' at the ridge line and 19' at the outside points. It also has a 10' by 2' (or 2' 6") side skirt. I us a WBBB XLC hammock so the 12' ridge line is a requirement. The doors are 3' 6" 'long' (point to fold) giving the tarp a 7' width at the base.

Here is a model of the tarp:
DSC_0281[1].jpg
DSC_0282[1].jpg
DSC_0283[1].jpg


I plan on using LineLoc3 on the doors and the sides and D rings on the ridge line and the center pullouts. I have spaced the center pullouts so they line up with the corners of the doors, but I am not sure it this will work, they look very close to each-other.


Questions:

1) Is there a tape that works with silpoly? Like the 3M VHB double sided tape?

2) If I have the pullouts at the corners only there will be 10' between them, is that to far?

3) I am thinking that I will go with out cat-cuts because of the additional 2'+ of fabric attached to the bottom of the sides, this seems that it would make it extra complicated to sew / build and probably defeat the reasoning behind them.


And of course any thoughts on the design and shape?


Wolfman

[ylnfrt]

Q 1- don't know but I believe that the 'sil' negates the use of tape as not much of anything stays stuck to silicone.
Q 2- If you are putting tieouts at the upper corners of the 2' side walls and staking the bottom corners of the sidewalls you should be able to pull it fairly taught,
but in high winds you may experience some flapping of your tarp. you may want 1 or 2 more tieouts along the top of the sidewall.
Q 3- On of the traits of the silpoly is that in has little stretch therefore catcuts are not necessary.

this is a BIG tarp!
If you would - explain the reasoning behind your design of adding the sidewalls. Is this for a winter tarp or just 3 season use. If for winter- I would think that the 4 open triangular spaces might be a problem when it comes to a blowing winds which tend to rob the heat from our quilts.
I think you are right about the placement of your pullouts being too close. The norm seems to be @36" - 40" in from the peak/ where your suspension attaches/ and @ 20" down on the sides. Have you considered using one of the poll mods (internal or external) to open-up the interior. The reason I ask is that you can save having to carry/ use 4 stakes as well as the pullout lines.

[Wolfman]

I'm working long nights right now so I just haven't had any time to respond.

Winter tarp only, I have a HG CF tarp that I love, its just not wide enough for cold winter months. Originally I was going to make this out of CF, but that got real expensive real fast!

I'll look at my cut pattern and see if there is the material for the bottom of the doors. I try that one end won't be a issue, but I'm not sure about both ends. I guess if I had one end sealed and both sides, the other end could have a gap at the bottom.

I have never used a pole mod, the look interesting. I guess I should do some more research on that.

Also; Any thoughts on the best way to secure the ends? Velcro / loop & toggle / ??


Wolfman

[Wolfman]

Working with a model of the tarp, it seems that if I fill in the gaps at the ends of the tarp the drops and the doors don't line up. I either have to sew them so they only work in the "closed position" or just sew along the door bottom and leave the corners open. They could be staked down together so there is not a gap, but I think a good wind would still work at opening them up.

Zippers seem excessive and heavy, Velcro? Maybe but in the snow/dirt that seems like it won't last either....

My thought behind the dropped edge is that it would give me good width and height, and I could secure it to the ground with stakes and greatly reduce the wind blowing under the tarp. In snow it would be easy to pile some up along the outside to add additional protection.

Maybe I make one side of the doors with the added lower panel and make the other side straight across. This would give me three sides of good if not great wind / rain / snow protection and one side that closes up but leaves an opening at the bottom. If I ever do a hot shelter this would be a good idea anyway.


I also received the fabric from RSBTR, what great stuff! I really like the look and feel, much better then the rip-stop look. I am going to try some different VHB tapes on a 1' wide section and see if any of them would work with the fabric. I'll post the results and how I end up testing the samples.

Wolfman

[CamoDeafie82]

personally.... using your cut pattern as a base; I would give the 10' 6" x 30" (assuming half of 60" width) extra sides, cut/diagonal cut corners that lines up with the door start edge (trace a line from peak to the seam between the longer edge and the start of the shorter edge), this would give you a hex shape with roughly 8-9 ft bottom edges, and then the doors could be staked down with one stake. As for closure? I think toggles and loops or buttons and loops could work pretty good. Especially if the buttons or toggles are very lightweight... The other option is to simply make a big big rectangle tarp that can be set up with doors..although the fabric width is what's limiting your options... but you might be able to get away with having a large center panel with no ridge seam, and then add extra fabric on the sides (3x60=roughly 180")with a 3-panel tarp. You say you got 15 yards? how big would the rectangle with 5 yards each side be? This would give you a rectangle tarp of 15 feet by just under 15 feet. With that, you could cut two triangles 15 feet wide by 1.5 feet to get your 12 ft ridge line, and still have the huge sides.

EDIT: Actually this might be the best way to do it with the least amount of fabric waste.
the center panel seams should be on top of the side panels, and with this, you could put panel pull outs on the side seams instead of dealing with sealing the stitch boxes on the bare fabric (the seams would also be the reinforcement, if you do bar-tacks on the pull out loops). doors could be 48" wide each, with the peak being 18" in from the original rectangle ends, and this would make the shelter much more spacious feeling. For even less fabric waste, you could just make it very close to being a square tarp.. minus a few inches on the sides for the seams. It would be roughly 14" and few inches wide, by just under 15 feet...

With the rectangle/nearly square tarp design, you could have a footprint of 8 feet wide and 6 feet long, or 6 wide and 8 long, but with a ridge line of 15 feet and if use panel pull outs, basically a winter palace feel to it...a height of more than 7 feet. And because of it being nearly a square, you could also pitch it as an enormous fly in good weather, or do porch mode with a 3 sided back for the view.

[Wolfman]

Thanks CamoDeafie82,

I like the idea of the porch mode, I do that a lot with my current tarp. I'll draw out some of your ideas and see how they fold up. I really like doing the models, it is a great way to figure out different options / layouts with out wasting anything. I'll post what I come up with, although maybe not tonight.

[Wolfman]

So after going over several designs and building models, I am going to go with a square tarp, actually not quite square, about 14' x 15'. With the ridge line being 14' and the width three sections wide, so just under 15'. This will allow me to use the tarp at other times for different kinds of shelter and just general overhead tarps.

I am also going to work out a system to use my trekking poles as tarp poles to widen the top half of the tarp. I looked at CF poles and Other tent poles, but I really don't want to carry extra stuff on winter hikes, my gear is already heavy enough.


The two 15' sides (the ends) will have D clips at the center and at each seam, this will give me several different options for ridge-line locations. The edges (14' sides) will have one pullout at the center, two 4' out from there making a 8' center section and then two more at the outside corners.

I will also have two pull out on each side along the seam about 6' from each other, centered. That way all my sewing is either on a seam or along the edge.

Drawing attached (PDF)
Hammock Tent.pdf

I'm going to call it the Hammock Tent, because it dang near encloses my entire setup!

[Wolfman]

So I started making the tarp last night and am working on it today.

Stress Point circles
6" for the corners and edges, and 4" for the center pullouts.
DSC_0286[1].jpg

I used a hot knife to cut the material. The Membrane cut very quick and easy, the Hyper D30O took longer and was slow to cut, but no fraying and it finished with a clean edge. A note, if your circle is metal, running a hot knife along the edge of the metal to cut the circle sucks a LOT of heat out of the blade! I switched to marking the circle in pen and then I freehand the cut, that worked a lot better.

Tie Outs and Pull Straps
The tie outs are all LineLoc 3 and the Pull points are D's.
DSC_0287.jpg
DSC_0289.jpg

I pre-cut the 1/2" webbing with the hot knife, which worked great and then added the LineLoc or D ring and sewed a bar across the webbing several times (back and forth) at what will be the edge of the tarp. Each of the straps have a 2 1/2" section that will get sewn to the tarp and the additional stress cutout. Except for the two seam pullouts, they will be sewn directly on top of the seam.

QUESTION: Should I use the Big (3/4") D ring for the ridge-line pullouts or will the 1/2" D rings be strong enough?
DSC_0288.jpg


Center Pullouts
I sewed the webbing and Linelocs on to the center reinforcement patch first, I think this will make it easier and it gave me some much needed practice... Yea not the straightest lines in the world.
DSC_0292.jpg


And Finally for tonight, the BEAST I use for sewing, and old Kenmore 158.33 or Model 33. It's probably from the 60's and is all metal construction and weights a ton! But once I finally got is set up correctly it's been working like a charm.
DSC_0290.jpg


Wolfman

[CamoDeafie82]

Remember that the material is not full 60" width; so taking some inches off the 15 ft side leaves you with just about a 14 ft several inches and 14 ft, maybe add several inches for a nearly perfect square tarp.. altho so far things looks great! 1/2" on the seam panel pull outs should be plenty strong.. 3/4 on the ridge line pull out should be good.

[Wolfman]

Update; last night I sewed one of the edges, got the layout figured out and then sewed on the stress pannels. Now I know why everyone seems to go with triangles! Curves are hard to sew!!!! :O

Then I sewed the edgec seam, folding it once and sewing down the 14' keeping it as straight as possible, not great but OK I guess. Then folded that over and sewed again. So on the face you see just one seam, mostly.

This sewing stuff is hard work, both my neck and arms were killing me after I got ones side done. I also got the three center pulls done, I'll wait on the corners until both sides ares hemed. More work tonight.