HH performance of Ripstop by the Roll 1.1 oz Silpoly, Khaki

[Stephen Seeber]

Sam Farrington asked me to measure the hydrostatic pressure performance of the above fabric.  Five samples were obtained.

The results are as follow:

Average HH, mm water column, 3 drops or more:  10124.  Max for three or more drops: 11249. Min for three or more drops: 8577.

1st Drop to Appear, mm water column.  Max: 8999.  Min: 6397.

https://ripstopbytheroll.com/collections/waterproof-polyester-fabric/products/1-1-oz-silpoly?variant=7943419585

 

 

[Michael B]

Is that pretty good? I think they rate it much lower, correct? I am hoping to actually use some of their MTN silnylon for a tarp soon. Different animal, but if they rate their fabrics conservatively, then that is always a good thing.

[Ryan Jordan]

That’s really impressive. Can someone post a link to this exact fabric on the RRTR website? Looks like they have several different ones. At this level of HH, maybe it would make a nice bivy sack floor.

[W I S N E R !]

…

 

[W I S N E R !]

That is substantially higher than what they advertise, no? I sewed a pyramid inner floor out of it….sounds like it was an excellent choice!

[Michael B]

https://ripstopbytheroll.com/products/1-1-oz-silpoly

[Michael B]

And actually, I did make a splash bivy out of this and some of the monolight mesh they have. It came out nice, but I’ve not had a chance to test it. I only made it because I am afraid of creepy crawlers at night.

[W I S N E R !]

^I’ve been thinking same. High walls and a small footbox with a noseeum top. This sounds like an ideal bottom, especially for the money.

[Michael B]

The monolite fabric is much more robust, easier to sew, and with only a slight weight penalty over the noseeum in this application. Just a suggestion. Seeing the nice mesh inner you made, I would guess you are not too concerned about the sewing part like I am 😁

[Geoff Caplan]

Michael B – I know this is off-topic but I’ve seen people say that the monolite is bombproof but doesn’t stretch much, so isn’t so good for inners where some stretch can help it drape properly.

Have you used it enough to have an opinion on this?

[Stephen Seeber]

Hi Wisner:

The ISO 811 standard for hydrostatic head testing, in section 6.3 a-2, states that “for fabrics of closer construction, it is advisable to use a manometer which provides for pressures up to 2 m H2O.”  This is 2000 mmwc.

What you are referencing can occur when a test instrument range is limited to 2000 mmwc.  I suspect this is the case here.  My instrument can test up to 30000 mmwc.

 

Steve

[W I S N E R !]

So if I understand you correctly, they maxed out their testing equipment whereas yours has significantly higher range- and not subject to a “suggested” 2 M H20 limit ?

[Stephen Seeber]

This speculation on my part.  I looked on their website at water proof polyester fabrics.  The results  ranged from 2000 to 10400.  The measurements had qualifiers of > or ~ . I am going to send a message to them and ask for some clarification about their testing procedure.  If I get anything back, I will post it.

 

 

 

[Roger Caffin]

The measurements had qualifiers of > or ~ .
That is honest.
You see, while you can take a sample from a roll of fabric and test it, there are two problems with the results.

The first problem is how to define the ‘hydrostatic head’ itself. The convention is that you take the pressure reading when three drops of water (ie leaks) appear, but that is just a convention. I cannot remember whether the area to be tested is defined: big or small. Three drops over a 25 mm circle, or over a 100 mm circle?

The second problem is that the fabric and the coating are NOT uniform: they vary from place to place along the roll. To be sure, with a heavier fabric and a heavier coating, the variation is not that much, ad that is where the definitions come from. However, with modern UL fabrics it is not hard to get slight variations in the thread to thread spacing. With the light-weight coatings needed to keep the weight down, tiny variations in how the coating material was spread out can also happen.

So giving approximate values, or just saying ‘greater than’, is being honest.

None of these measurements address the problems of aging: how good will the coating be in 12 months? Nor do they address the question of performance under load: will the coating hold up under a howling storm?

Cheers

[Stephen Seeber]

Hi Roger:

I agree with all you write.  This fabric certainly had a fair amount of variation. You can judge from the max and min data I included.  However, ISO 811 bases the final value on the average of test samples, so the method is intended to somewhat account for variation. So, when the test specification says greater than or approximately, I don’t understand if they are communicating that a limit of the instrument was reached, especially, when it is such a nice round number, such as 2000, which is specifically referenced in ISO  811.  In any case, I have sent a message to RSBR asking about their test methods.  So, perhaps we can get some further insight on this.

Steve

[Sam Farrington]

Stephen,

Thank you for your testing of the fabric.  Much appreciated.  Note the color I sent you has been sold out, but there are other colors available on RBTR.

[Michael B]

I know this is off-topic but I’ve seen people say that the monolite is bombproof but doesn’t stretch much, so isn’t so good for inners where some stretch can help it drape properly.

Geoff,
The monolite is stiffer than noseeum, yes. If you are working with a fabric which you need a good amount of stretch, this is not really the material you want. I was advocating using it on the top of a bivy sack, or if you are building something like a single wall shelter, where it might actually have a structural purpose. Noseeum is probably the better choice for a non-structural inner.

Sorry to veer off topic.

[Michael B]

Note the color I sent you has been sold out, but there are other colors available on RBTR.

This is likely not a thing, but might color play any part in the waterproofness? I know with adhesives, the substrate can be a determining factor in good adhesion. I would assume the colors are all basically the same chemical, just with a different pigment.

[Roger Caffin]

might color play any part in the waterproofness?
Imho, extremely unlikely.
Certainly with silicone coatings, the coating fully encapsulates the fibres. The dye on the other hand is absorbed into the fibres.

Cheers

[Jon Solomon]

I wonder how that compares then to the 1.1 oz Silpoly PU4000 fabric from RSBTR that is touted as the high water resistance version of the fabric (with a little less stretch and the requirement to use PU-based sealants like Seam Grip instead of silicon-based Silnet)?

I had been thinking that the Silpoly PU4000 fabric might be a better choice for a pyramid, but these results have me wondering again about that choice. Especially since I bet that over the long run the pure silicon coating will last longer than the sil/PU hybrid coating.

[J-L]

I don’t see any reason to use the Silpoly PU4000 fabric for a tarp and would recommend against it. Due to its thick PU coating, silpoly PU4000 tears more easily than the standard 1.1 oz Silpoly fabric once a hole is present (buy a sample and see for yourself – the difference is startling). The standard 1.1 oz Silpoly fabric has now been used successfully in many tarps and is used by some cottage companies, so it seems strong enough and waterproof enough.

So if you made a tarp out of PU4000, you’d end up with something that is heavier, weaker and bulkier. IMO, the only real good application of PU4000 is as a tent floor. I have a tent inner that uses PU4000 as the floor and it has held up well. But now with these HH ratings, I would probably just go with the standard 1.1 oz Silpoly for a floor.

[Jon Solomon]

I’ve used the 1.1 silpoly in the Fallen Leaves pattern from OutdoorINK at RSBTR for a minimalist pyramid (300 grams) and it has performed really well in heavy rain, hail, and of course sun.

There’s obviously no reason to switch to PU4000 silpoly. Thanks.

[Michael B]

The PU4000 variant, aside from tent floors as you have mentioned, would also be a good choice for applications where one would want to have the ability to seam tape. That may be valuable for some builders.

[Sam Farrington]

“I wonder how that compares then to the 1.1 oz Silpoly PU4000 fabric from RSBTR”

Once consideration mentioned is the weight.  The silpoly is spec’d at 1.24 osy, silpoly PU4000 at 1.4 osy, a difference of .16 osy.  The 1.24 osy was already .18 osy more than the Extrem Textil silnylon 20D that did well enough in HH tests by Stephen and Roger; but I wanted something that would not sag for vestibule walls, and wondered how the silpoly would do with water resistance without the added weight of the PU.  Stephen’s results are more than adequate for me.

[Geoff Caplan]

Stephen – do you have any way to run an ageing test?

It would be very interesting to hear how it stands up.

Sadly, for those of us who’d like to order some, they seem to be out of pretty much all the usable colours. Hopefully they will be able to sort this soon, as it seems to be one of their most popular products…

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