Oct 23, 2006 at 10:47 pm #1219972
just woundering on what people use for tarp reinforments, im making a 5×9 poncho tarp and was woundering if 1.3 silnylon is enough for the reinforcements for the tieouts. or should i go for a 70 denier… or something even stronger? (think oware uses 200 denier)
mike!Oct 24, 2006 at 1:31 pm #1365442
1.35 is plenty strong enough on a 1.35 tarp. It’s more a matter of how they are attached and size.
Size- about a 3-5″ distance fron the corner is fine on a small to med size tarp. (half of a 6-7 suare will end up as a 4″ after rolling the edges into the hem.)
For ultimate strength, bond them to the tarp with a very light coating of silnet/silicone, let dry, before rolling the edge hems. (We use a special double sided permanent tape instead of silicone-don’t ask- none to sell…)
Wider perimeter hems (more than 1/4″, 1/2 to 1 is good) are srtonger.
Roll the reinforcement into the edge hem as you make the hem and then stitch the reinforcement(across the hypotenuse of the triangle) with a med to wide stitch spacing about 1/4″ from the edge of the tarp on the reinforcement. The stitching is more to prevent bond failure than attaching tarp to reinforcement.
If you really want to go all out, add another line or two of stitching mid way through the reinforcement perpendicular to the hypotenuse.
A key DYI pitfall is setting stitch spacing too tight or to bartack/zigzag a tieout on too tight as that put too many stitches too close together and thus make a rip-along-the-dots possibility. Try wider space dual bartacks rather than one beefiers one. The pretty big beefier ones are best for heavier fabrics.
On many smaller tarps, you can do without the reinforcements all together (at least everwhere but the corners and maybe ridgeline) if you use wider hem and double stitch (two rows) the hem. The width of the hem spreads the tear force over a wider area very well. Just keep the tieous near the tarp edge so the force falls on the bartack and then the two rows of hem stitching. I’ve never had one tear out made this way and it saves a bit of weight.Oct 24, 2006 at 5:26 pm #1365452
Ron, thanks for the insight, also answered my follow up question (i heard talk of people using non waterproof tieouts to prevent water from collecting in reinforcements) i was playing around with my fabric tonight, and i might need a nice sheet of plywood to pin/clip the silnylon down for my cat cuts, tape doesnt stick, weights need to be huge+heavy to keep the stretchy nylon stretched with all the wrinkles and such.
mike!Oct 24, 2006 at 6:28 pm #1365458
@vickrhinesLocale: Central Texas
A 5×9 poncho tarp doesn’t really need any catenary cut at all. You can make if out of a single width of 60″ fabric and avoid a center seam entirely. That means no catenary. If you put cat curves on the sides, it will reduce your coverage significantly and coverage is at a premium under a 5X9.
If you make a cape instead of a poncho, you won’t have to mess with a hood or the leakage and distortion that the hood produces.
A cape uses fasteners set inboard of one of the long hems to form the hood and to pull the sides around your shoulders. The shape is conical instead of like a poncho, so it is better in the wind. a 5×9 will cover your pack nicely.
One trick is to make your corner reinforcements into pockets for the guy lines. The reinforcements can just turn inside out to hold the lines and are held closed with strategically placed Velcro.
Note the sew-on snaps that create the hood, set 6″ inboard of the hems. A couple of more sets along the “front” will keep it closed in the rain.Oct 24, 2006 at 10:33 pm #1365469
ya i’ve messed around with the cape idea before, but im a devoted trekking pole guy :/ which kinda gets in the way of the whole cape protection. ya i think i’ve given up on the cat cut sides, to much work and not a lot of benefit. I’m deffinitly going to use your guyline attatchment system, gotta re-read how to do the ones in the middle of the tarp. but i’ll figure her out.
thanks a lot!
mike!Oct 25, 2006 at 9:04 am #1365483
Is that Richard Branson in that cape?
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