Questions about making a silnylon tarp?

[Big Dawg]

I have 8 yds of grey silnylon & am soon going to make a "MacCat style" hex tarp. I'm new to sewing, & will be using my neighbor's sewing machine. Some of the other projects I was considering include an underquilt for my new hammock, but based on time & sewing skills, I'm having Patrick (KAQ) make my underquilt. Making a tarp seems simple enough, though,,,, so, here's my questions:

#1. What's the best needle to use for 1.1oz silnylon?

#2. What's the best thread to use to construct this tarp? I've seen 100% nylon thread in my local fabric store, but notice Brian (OES) uses urethane coated 100% polyester thread.

#3. Is webbing another name for grosgrain ribbon? I plan on lining the edges w/ a fabric, like Brian/OES does,,, & I think I remember a past post explaining he used grosgrain ribbon.

#4. Before lining the edges w/ webbing, do you still fold over the edges of the silnylon (like you normally would if not using webbing)?

#5. The tie-out corners. It seems I remember a post where a small piece of regular nylon is sewn on the top & bottom of each corner tieout to reinforce the tie-outs. Brian's website states using 1000D Kevlar ripstop for those corners. Should this reinforcement fabric be waterproof, non-waterproof, DWR or what,, or does it matter?

#6. D-rings for corner tieouts. Brian uses ABS plastic D-rings. What does ABS mean?

I think this does it.

Thanks for all reply's!!! :D

[Footslogger]

Can't help you much with the silnylon questions ...since I'm still in the learning states myself.

But ABS stands for "Acrylonitrile Butadiene Styrene". It's a type of plastic that allows things to me made light and rigid.

'Slogger

[general]

size 90 or smaller, basicly so the needle hole isn't much bigger than the thread dia.
i use bonded nylon thread (B46) for tarps
i would still fold the edges for strength even when banding with ribbon
i use 1 sil/nylon triangle re-enforcement piece, on the inside only, at each guyout point
after finishing the tarp, you should coat every millimeter of thread with silnet or regular silicone. that way if a thread does pop, later, under stress, it won't unravel.

[bugbomb]

Dawg - grosgrain ribbon is not the same thing as webbing. The ribbon is much lighter, and will be easier to fold and sew around the perimeter of the tarp if you feel that is necessary. You can get it pretty darned cheap at Walmart in a 7/8 inch width.

If it were me, I would definitely still hem the edges before lining them. Although, on my own tarp, I did not line the perimeter with ribbon - only at the guyout points. I basically folded the edge over twice and hemmed - I feel that this triple-layer of fabric, with no exposed edges, is plenty strong. One advantage to lining the edges might be that you minimize stretching/distortion under tension.

I'm not sure about the reinforcement material. I used uncoated nylon - I figure it may get wet and soak some water, but it will dry. If you use something coated (silnylon or urethane coated), be very careful that you seal the seams around it, otherwise it might hold water like a bag.

[hammock engineer]

I'm not sure about the reinforcement material. I used uncoated nylon - I figure it may get wet and soak some water, but it will dry. If you use something coated (silnylon or urethane coated), be very careful that you seal the seams around it, otherwise it might hold water like a bag.

I never thought of that issue. I am working on one now. I am just making a simple 9x9 square with tie outs at the corners. I'll post some pics when I get it done.

If anyone needs somewhere to order sil-nylon. I ordered seconds from Noah Lamport for $2.75 a yard. Recieved it in a week and it looks fine. Just do an all in one order. They charged a $5 cutting fee and around $5 for shipping off of the bolt.

[bugbomb]

HE - someone warned me about that before I made mine. It could by overly cautious, but I didn't see much advantage to using coated material anyways.

[Just Jeff]

Brian folds his edges under before he adds the grosgrain ribbon. I think the ribbon does two things:
1) Makes the edges stronger, which could be an advantage in high winds - think about how much the tarp flaps around when you're first setting it up in windy conditions.
2) Spreads the load. If you just hem the edges, then pull on the guyout point, it'll stretch a lot at the guyout point and not quite as much around the rest of the tarp. Adding the grosgrain ribbon adds some stiffness around the perimeter, starting at the guyout point. This means that force applied to the guyout point is transferred to more of the perimeter...resulting in less flapping when stressed.

Is it necessary? Probably not - plenty of tarps keep folks dry without it. But there's a video on my website of the MacCat in probably 30kt winds and it's barely moving.

Will it have the same effect on a square tarp? Probably not unless you curve the sides...but there's only one way to find out!

His kevlar is not waterproof, but it doesn't matter. The tarp is already wet if it's raining anyway, and it's such a small amount that it dries quickly enough when the tarp dries.

Where are you putting the seam to get a 9x9 square?

[hammock engineer]

I am going to sew 2 4.5'x9' pieces of sil-nylon together, adding 2" on each side for seam allowances. That should put the seam running down the middle. It won't be corner to corner, but that should not matter. Or will it? This is going to be my first sewing project, so I wanted to keep it easy.

How much weight would it add to put that around the outside? I'm planning on making 2. If it only adds a couple ozs, I will put it on the 2nd one.

[general]

How much weight would it add to put that around the outside? I'm planning on making 2. If it only adds a couple ozs, I will put it on the 2nd one.[/quote]

ounces add up. sil/nylon doesn't need the re-enforced edges, only a folded hem around the edge. the re-enforcement triangles at each guyout are enough. make these 6 or 7 inches on the hypotenuse,and do without the banding around the edge to save weight. the banding's got to add 2-3 ounces. the larger the triangle re-enforcement piece is the more tension it distributes.

[hammock engineer]

One more question for everyone.

What should I use as the tie out lines. In Ed Speer's book he calls for 1/16 inch Spectra pulse line. Should I use that as the side tie outs and the tie outs from the corners to the trees? I was also looking into using shock cord for all the tie outs. That would provide a little give to them, which should help in stronger winds.

[Just Jeff]

IIRC, Brian said the grosgrain on his tarps is about 1.5 oz.

I'm not sure how that seam will react - looks like a lot of force pulling the seam apart. Maybe run an extra line down the seam and use a thick seam-seal mix just to be safe.

I'm not sure I'd use shockcord by itself without some sort of "safety catch" made from Spectra (or whatever other non-stretch line you use). Most tarp tensioners only take up slack in a line rather than providing any "structural" support. Make sense? Here's an example:
http://www.tothewoods.net/HomemadeGearTarpTensioners2.html
See how the line runs through the middle of the tensioner? So if a wind gust stretches the tensioner to full extension, the line itself is providing the structural support and it doesn't matter much if the tensioner fails.

[stupe]

Favorite thread for me is Gutermann's polyester thread. I used a contrasting color on my purple silnylon tarp and it looks kind of cool. I wouldn't use any urethane coated thread since you're going to seal the seams, and maybe the urethane coating would prevent the silicone sealant from impregnating the thread. Maybe not, but keeping it all sil seems better to me.
I'd keep with that philosophy on the tie out reinforcements, too. Two layers of silnylon tucked under a hem is pretty strong. Even if you reinforce with kryptonite, it's only going to be as strong as the stitches going through the sylnylon layer anyway. Like that saying "a chain is as strong as it's weakest link', you know.
I did what bugbomb said above, folded the edges over twice and stitched through the three layers. I guess the ribbon could only make it stronger without adding much weight, and I wish I'd done that, although so far it's holding up good.
general above said that nice big corner reinforcements distribute the stress better, and he was right.

[hungryhowie]

The best thread I've ever used is provided by Thru-hiker.com. It's stronger and less messy to work with that Guterman, and cheaper too. Use the smallest needle you can and still fit the thread through, typically a 90 or smaller. A grossgrain ribbon perimeter is overkill...way overkill. I've designed, made, and tested many tarps and have yet to understand why it's sometimes used in this way. Because grossgrain also absorbs moisture, it weighs much more than 1.5-2.0oz when wet, and it takes much longer to dry than silnylon. I've experiemented with a silicone impregnated binding as well, but this did nothing for performance either. No, the best way to seal a silnylon edge is to burn it to prevent fraying, turn the edge under and hem. I lightly reinforce corners with a second layer of silnylon and use grossgrain for the actual pullouts.

-Howie

[fiddlehead]

For tieing out the guys, i found that the super strong nylon string that union bricklayers use is the lightest. I have it on my sil-shelter going on 6 years now and have never broken one. I've been in some pretty big storms too. good luck. i think you'll find that the reinforced sil-nylon is pretty damn strong although very slippery and not easy to work with.

[Big Dawg]

Thanks all, so far!!! I can't wait to get started!!! :D

[Big Dawg]

I lightly reinforce corners with a second layer of silnylon and use grossgrain for the actual pullouts.

-Howie


How strong & long-lasting is grosgrain ribbon as "pullouts". Is using nylon webbing & heavy duty plastic D-rings overkill?


.

[Big Dawg]

The best thread I've ever used is provided by Thru-hiker.com.
-Howie

They have Tex 40 (used for tarps/packs/sacks) & Tex 24 (for apparel/sleeping bags). Obviously I'll get the Tex 40 to make my tarp, but do you think it would be ok to use Tex 40 to also make me some rain pants using 1.1oz nylon ripstop w/ DWR?

[general]

How strong & long-lasting is grosgrain ribbon as "pullouts". Is using nylon webbing & heavy duty plastic D-rings overkill?


.

86 the plastic man. use the nylon to make a loop (better both ends of the loop are sewn to the inside of the tarp rather than one end on the top and one end on the bottom). plastic weighs more than nylon and you've got to use the nylon ribbon to attach the d ring anyway.

[general]

They have Tex 40 (used for tarps/packs/sacks) & Tex 24 (for apparel/sleeping bags). Obviously I'll get the Tex 40 to make my tarp, but do you think it would be ok to use Tex 40 to also make me some rain pants using 1.1oz nylon ripstop w/ DWR?

you can use the tex 40 to do just about anything except maybe underwear and anything thats gonna hold down. you will have to seal the seams on the rain pants too.

[Big Dawg]

86 the plastic man. use the nylon to make a loop (better both ends of the loop are sewn to the inside of the tarp rather than one end on the top and one end on the bottom). plastic weighs more than nylon and you've got to use the nylon ribbon to attach the d ring anyway.

Sorry, I'm new to making my own gear,,,,, not sure if I follow ya.

"86 the plastic man"??? what does this mean?

I thought my choices were: #1. Use nylon webbing, make a loop w/ D-ring in the loop,,,,, or,,,,,, #2. Use grosgrain ribbon, make a loop,,,,,, attach either one to tie-out corners.

Either option I choose, I had planned to sew one end on top & one end on bottom of tarp,,, but General,, you say both underneath/bottom,, why???


.

[Just Jeff]

"86 the plastic man"??? what does this mean?

Haha...being "86'd" is when you get kicked out of a bar...guessing he means get rid of the D-rings.

[general]

Sorry, I'm new to making my own gear,,,,, not sure if I follow ya.

"86 the plastic man"??? what does this mean?

I thought my choices were: #1. Use nylon webbing, make a loop w/ D-ring in the loop,,,,, or,,,,,, #2. Use grosgrain ribbon, make a loop,,,,,, attach either one to tie-out corners.

Either option I choose, I had planned to sew one end on top & one end on bottom of tarp,,, but General,, you say both underneath/bottom,, why???


.

get rid of plastic parts. sorry for the misunderstanding. by sewing your webbing on the underside only, the two ends of the webbing will parallel each other. if your webbing is 1" wide and you have one end on top and one end on the underside, your spreading the load over a 1 inch area. if the ends are parallel to each other your spreading the same load over a 2" area. also, if something were to happen, and the thread holding the guyout poped, by putting the webbing side by side you would still have half of it attached (maybe), depending on your thread pattern.

i didn't mean to throw you for a loop there.

also, plastic becomes brittle in low temps. i'm not saying it will break, but under the same conditions, the nylon webbing is stronger.

one other theory: if you have the edge of nylon webbing exposed on top of the tarp, as water runs off of it, the end of the webbing will create a daming effect forcing the water to run around it, thus saturating the webbing, and inturupting water flow. with the webbing underneath, you don't hinder the flow. that may be splitting hairs (or grams) but true none the less.

[Big Dawg]

OK, thanks General/Jeff! So I should use nylon webbing instead of grosgrain ribbon for the tie-outs? Just to clarify..... nylon webbing is the strap/handle material I usually find on the bottom of stuff sacks, etc?

[Just Jeff]

That sounds like nylon webbing...think of the part of a backpack strap that you pull on to adjust it.

D-rings are a matter of preference. The ones Brian uses might add about 4g to his tarps. I think his grosgrain and D-rings make his tarps very strong, but for most trips that level of strength is not necessary. (Of course, the one time you need it and don't have it is when it'll really count...I'm glad I had this tarp on the Winnemucca trip.)

OTOH, JRB uses thin nylon webbing tie-outs and I don't notice any wear on them.

Lots of options out there - just pick the trade-offs you want!

One more thought - you might put a short length of grosgrain ribbon along the hem, perpendicular to your long seam, to reinforce it. Wouldn't be a big deal for a normal tarp, but using it like you plan to will stress that seam differently. Dunno...might be worth considering.

[hungryhowie]

Well, Thru-hiker.com used to only offer one weight of thread, tex40. I've used it to sew a couple of down quilts and such, so it can certainly be used for that as well, although I bet the tex24 is much better for that application. I agree with general, plastic parts are just a failure waiting to happen. Long after those plastic rings have broken, the webbing/grossgrain will still be holding strong. I've never seen a reason to use real webbing for tieouts, either. Using a cue from Integral Designs, whose sil shelter provided coverage for me for more than 2500 miles of hiking and in many storms, I just use grossgrain. I fold the ribbon in half over the fabric and sew it onto the fabric. When you get to the corner, continue sewing the grossgrain until it's sewn all the way down. Run a second seam down the gross grain. Make a loop with the gross grain, line it up with the fabric's edge, and attach it to the fabric. double seam the second side to re-inforce and you're done.

-Howie

[Big Dawg]

So many options,,,, I'm lovin the detail,,,,,, thanks again, all. :D

[Just Jeff]

Thought of a way that might work for your tarp with only one center seam.

Rather than a true square, sew the pieces together and make as much of a square as you can...it'll come out looking like a square with the last bit of side corners cut off. Almost like a hex. Then put a tie-out on each of the corners on each side, but tie one piece of cord to both of tie-outs (one end to one corner, one end to the other). The length of the cord should finish off the square shape when staked out...use only one stake.

I haven't done the math to see how much area you'd lose, but those last several inches aren't very useful in diamond mode anyway because they're way out on the ends.

Anyway, it's just a thought.

[Patrick]

I'd thought of doing the same thing, as much for saving half the stakes as anything. If you do this, let us know how it works out.

[Big Dawg]

I have 8 yds of grey silnylon & am soon going to make a "MacCat style" hex tarp.

Thanks for your recent response, Jeff. Sounds like a great idea. :-? Per my 1st post, (see quote above), I had decided to make a hex tarp, because I didn't have & couldn't find material wider than 62+ inches. Your idea would work great, reducing material & stakes, therefore reducing weight. I can see the attachment in my head,,, kinda the same idea as the rear tie-out of a Tarptent Squall/Virga-----lines come together in a "V" to form as 1 line down to 1 stake. I will draw up some plans to see how this looks on paper. I'll post back.

[Big Dawg]

Well, here's the deal Jeff. I only have enough material (length) to construct an 8x8 tarp (w/ diagonal ridgeline), & the corners on the sides that would miss the last section, as you mention, would be very small, missing approxamately a foot from the end. I think I'm gonna stay w/ the Hex design, though.

[Just Jeff]

Most tarp tensioners only take up slack in a line rather than providing any "structural" support. Make sense? Here's an example:
http://www.tothewoods.net/HomemadeGearTarpTensioners2.html

Getting a lot of missed pages on the site b/c this link is wrong...try this one instead:
http://www.tothewoods.net/HomemadeGearTarpTensioner2.html