Sil tarp corner reinforcements

[simonm]

Hi all,

I am in the middle of my hammock tarp build and trying to decide on the best way to do the corner reinforcements. I have borrowed an idea from how Wilderness Logics do their tarps but sewed it a little differently so the force seems to be only along the sewn edge, with all the stitching remaining with the hem of the tarp. It is done using 38mm grosgrain doubled over a length of 25mm grosgrain attached to a D-ring.

What are people's thoughts on this - will it work ok, any foreseeable issues?

The photo is just a roughly sewn mock up on a scrap piece of sil.

Thanks.

[Redback]

If you've gone to the effort of doing a mock-up on some scrap I would throw it in the vice and pull it as hard as I could. That will give you your answer of whether or not it will hold.

Nice sewing BTW.

[simonm]

Thanks.

I have tried pulling it as hard as possible between two people and not been able to break it or have any elongation of stitch holes so I think it should be ok.

[ofuros]

Looks strong enough to me, Simon....those blustery South-Westerlies that blow-in down your way will have the last say.

Reminds me, that I have to modify my 'Lil red' & Cuben tarps, by adding some little mesh tie-out pockets,
to tuck away the my lines so they don't get tangled up when packing / unpacking.

Enjoy your new DIY tarp.

Last edited by ofuros on Mon 21 Apr, 2014 8:39 pm, edited 1 time in total.

[simonm]

Thanks mate. Yeah only time will tell.

[simonm]

The tie outs above work really well, no issues but am thinking about this design for my next tarp. Ignore the less than perfect stitching and asymmetry, this is just on a scrap piece of sil. I will probably stitch it a little differently next time but the design is the main thing. I have a tarp ready to be made out of Argon sil and will give it a decent test but would appreciate people's thoughts or suggestions.

My line of thinking is that it will place the majority of the strain along the stitched edge of the tarp.

Thoughts??

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[Orion]

I will start out by admitting that I have no real understanding of this subject. But my intuition tells me that a patch of reinforcing material that is well attached to the underlying tent fabric would serve to spread the force out more evenly than strips of fabric or webbing. The patch seems to be a common theme in commercial tents anyway.

[simonm]

Cheers Orion. I appreciate your feedback.

I know conventional wisdom says to reinforce the tie out with a patch, but the reason for me trying this method is I no of at least 2 hammock tarp manufacturers who dont use any reinforement patch and keep the stitching along the edge rather than intruding into the main body of the tarp. Also the way I do the rolled hem on the edge means I will be stitching through 4 layers of silnylon plus the grosgrain, and on the very corner it will be 8 layers. I am just wondering if that would be enough, if I am not stitching through the body of the tarp? I have made a similar tarp using no reinforcement patch, as outlined above, and it has held up fine.

[Moondog55]

I've done this slightly differently by twisting the tape to make a loop and running it right to the corners.
My experience says if doing this you need to make the length of tape along the tripled edges much longer and be prepared for some deformation of the tarp as well.
I looked at my Moss tarp too, Bill Moss used a much heavier tape than Grosgrain and bar-tacked at 100mm intervals but Moss also used up to three layers of reinforcing [ each slightly larger in size] as the tarps increased in size. Stands to reason bigger tarp has a bigger sail area so stresses are bigger, so the trade off is going to be weight Vs durability as always.
I'm still not sure about using different fabrics for the reinforcing but Evan at TerraRosa seems to have no problems using the heavier weight Cuben for this purpose.
I would say that edge taping is fine for small tarps but not suitable for larger ones

[simonm]

Thanks Moondog. I think the multiple layered reinforcement is often used in sail making. I am deliberately trying to keep it minimalist but as you say this comes with it's own potential risks. I will extend the grosgrain further down the tarp, but am unsure whether to bother with any further reinforcement.

I don't think I will know until I test it. I have had some feedback from an Australian gear maker who also has some experience in the sail making world and he seems to think it will be ok.

Here it is with better stitching.

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[simonm]

After some stress testing, involving the sil tied to an immovable object, the weak points are certainly the ends of the grosgrain stitching and point of the triangle on the tarp body. Although considering the force I applied to it they all held up well. I might try a reinforcement patch made up of the silnylon next and see what difference that makes.

[Moondog55]

Also
Rather than stitching along the length of the tape try and use a series of 3 bartacks in the centre of the rolled edge, tape 300mm on each side, bartacks at 100mm; that is how Bill Moss did all his and my Pentawing shows no sign of stitch failure after 30 years of use

[simonm]

Also
Rather than stitching along the length of the tape try and use a series of 3 bartacks in the centre of the rolled edge, tape 300mm on each side, bartacks at 100mm; that is how Bill Moss did all his and my Pentawing shows no sign of stitch failure after 30 years of use

I will play around with some different stitching tomorrow if I get a chance.

[simonm]

Here is the latest rough incarnation with silnylon reinforcement on both sides.

Initial tests suggest it is much stronger, as Orion suggested .

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[perfectlydark]

Is that a semicircle for the patch?

[simonm]

Yes its a semi circle.

[perfectlydark]

Sorry it was a dumb question planning on building a tarp soon doing some learning

[simonm]

The blind leading the blind! I don't really know what I am doing either apart from testing different ideas. on the last one I actually cut a circle out of the silnylon, then cut that in half and folded this over the corner of the mock tarp and sewed across the reinforcement. I then did a rolled hem which incorporated the reinforcement patch. The reinforcement patch has a raw edge exposed so I will need to deal with that first, although this sil does not unravel at the edges like uncoated fabrics.

It definitely seems stronger but whether it is needed, I am not sure. If I was going for a bombproof tarp given what I know now, which is very little, i would go with the last version or a variation.

[perfectlydark]

Lol! Well if your blind your not doing bad! Ive seen a few patching ideas but I like the one you put up today. As in, I might be able to pull it off!

[simonm]

I just found this post by Ron Bell of MLD on the backpackinglight forum which has some handy ideas in it.

Ron Bell MLD tie outs via BPL.PNG (83.55 KiB) Viewed 43140 times

[ElvenCraft Gear]

I find a couple of radial stitches works well on the tarp re-enforcements.
Most of the destructive strains tend to run along the edges of the tarp. Double roll hem these edges and use some heavier material for the re-enforcing patch.
When you add the tie tag, make sure the loop is on both sides of the tarp/re-enforcing and stitch through the lot into the rolled hem.

[simonm]

Each tarp I have done I seem to do a bit different.

My current tarp is a bit more traditional, though haven't done the tie outs yet. I have just used the same 30 denier silnylon for the reinforcement, as this is a small tarp. I tried bonding the patch but found that to be a pain.

[Franco]

To bond silnylon (for repairs in my case) I smear a very thin layer of undiluted silicone on both pieces of fabric, let it stand for 15 minutes or so then press together and put some weight on top.
Takes up to two days to fully cure.

[simonm]

Hi Franco,
Yeah it was the waiting time that was the pain.

[ElvenCraft Gear]

Yeah, Silnylon repairs are all about patience.
You can try all sorts of seam tape and double sided adhesive, but nothing sticks to silicone except silicone, and because silnylon is airtight, it cures really slowly.
When you put in re-enforcing panels bigger than 100mm, You can get some movement between the 2x layers which means the re-enforcing doesn't "pull" properly when finished. To avoid this, stitch your centre or radial lines first and work outwards, then underfold the edge of the patch and stitch the final patch edge hems. Then when it's all sitting nice double roll hem the tarp edges with the re-enforcing patches rolled in with the main tarp sheet.

[Moondog55]

I'm just wondering if the fusible lining that Cecile uses when she makes dresses could be used to hold silnylon together while sewing its an iron on type but low heat. May have to try that if and when I get the new window in the dining room finished ( talk about DIY:-( Demolition before building and my back will be in spasm for a week )

[undercling-mike]

Here's how I made the corner tie outs on the hex tarp I recently made:

Tarp tie out

The edges of the tarp are triple rolled and I used three pieces of 1/2 inch grossgrain to sandwich the edges of the tarp (i.e. it looks the same from the bottom) and form the tie out loop.

Here's a picture of the tarp set up for the first time

[simonm]

More than one way to skin a cat that's for sure.

[ElvenCraft Gear]

Wow Mike !!
That hex tarp is really good !
The corner tie outs are beautifully done. - nice work.

[simonm]

Also
Rather than stitching along the length of the tape try and use a series of 3 bartacks in the centre of the rolled edge, tape 300mm on each side, bartacks at 100mm; that is how Bill Moss did all his and my Pentawing shows no sign of stitch failure after 30 years of use

Hey MD - I finally got to do a mini version of what you suggested for my lightweight tarp, and it only took 12 months . I should have it finished and ready for testing today.

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