How waterproof is silnylon tent fabric

[joseiri]

I have just tested my Tarptent - Rainbow 1 (3 years old now) by creating a pool of water in a fabric panel. It seeps a lot water. The 'Outdoor Wilderness Fabrics' - 1.1 oz ripstock silnylon fabrics seconds I have just bought also seep water. Has anyone tested their silnylon tent fabric for water holding capability and can anyone advise whether it is durable.

[Ent]

I have just tested my Tarptent - Rainbow 1 (3 years old now) by creating a pool of water in a fabric panel. It seeps a lot water. The 'Outdoor Wilderness Fabrics' - 1.1 oz ripstock silnylon fabrics seconds I have just bought also seep water. Has anyone tested their silnylon tent fabric for water holding capability and can anyone advise whether it is durable.

My Hilleberg fabric appears not to seep at all but not sure exactly what the fabric is. Surprise by Tarptent though there has been a rather long decision on more than one bulletin boards if the misting from heavy rain is water coming through or condensation been knock off.

Be curious to hear Franco's views on the water seeping through.

Cheers Brett

[Orion]

Not all silnylon is the same. Different fabrics and different impregnation/coating.

The "standard" silnylon (stuff you can buy at OWF) was informally tested in the first link below (it leaked at low pressure). In the second link a practical technique for improving the waterproofness of silnylon is described.

http://jwbasecamp.com/Articles/DryGear/index.html
http://jwbasecamp.com/Articles/Silnylon1/index.html

The proprietary silnylon fabric that Hilleberg uses is called Kerlon and comes in two weights. The waterproof rating is specified as the water pressure it can withstand without leaking.

Kerlon 1200: 20 kPa
Kerlon 1800: 30 kPa

The fabric store silnylon that was tested in the first link leaked at only 3 kPa.

For comparison, Sierra Designs claims that one of their urethane coated nylon fly sheet fabrics has a rating of 80 psi (about 550 kPa).

Sometimes the waterproof rating is given in millimeters. While this may also refer to pressure (a column of water of that height) it is frequently used to mean the amount of rain in a 24 hour period that the fabric can withstand without leaking. That's kind of a weird one, in my opinion. But without some context, none of these ratings makes much sense to the average tent shopper.

[Son of a Beach]

Franco once posted some pictures once of some Tarptent fabric slung over some furniture with a few litres of water sitting in it. No drips, after a few hours, I think was the result.

EDIT: Found it: viewtopic.php?f=15&t=4091#p46690 12 hours with no drips!

[Franco]

Joseiri
I have tested the "waterhead" of a few samples from TT and they all are somewhere between 1200 and 1500mm.
In my test I used a drain pipe 5 cm wide, 3 m tall . To pass my test the fabric did not let any water through for at least two hours, but mostly 4-6 hours.
Are you sure that the water is not seeping through the seams ? (they need to be sealed...)
The first picture is my "rig" (ignored my water spillage...) the second is the fabric failing after several hours with 1500mm of water on top of that.



Franco

Nik
The pictures I posted previously were of the fabric used for the inner, not the silnylon fly . That fabric is rated water resistant but yes it does hold water all day , however it was 1 liter with a max depth of 15-20 cm (can't remember now...) not 1200mm or so

[Ent]

Hi Orion

Thanks for that information it does help in the understanding so tent buyers are better placed to evaluate potential purchases. One thing I noted from reading Hillebergs catalouge is they apply ratings achieved from aged fabric. Franco's test it is valid for new material but might not be the same with the three year old material that has been exposed to sun, wear and goodness knows what agents such as sap, acid rain (hopefully extremely minor), etc. Then again it might perform almost as well as new.

I would think many people would aim for a ten year or greater tent life but this evaluation criteria often gets over looked with price and size to weight ratios getting most attention. It is a worrying trend that tents (boots, and lot of other gear) appears to be failing or more accruately not performing as well after a few years. My Kaon has a small hole in the zip protector flag where it got caught in the zip. Ok it was me or a friend that did that but I notice that the flap on the Hillebergs are not so prone to be caught by the zip. Good luck or good design? No idea.

The trend to light weight materials is not only resulting in a lighter grade base fabric, with 20 Denier being the current "acceptable" strength material but as mentioned this is not the only factor as coatings of the material adds to the weight. The trick is for the user to be aware what they are buying and the expected life from such purchases. It is rather hollow when someone posts a, "what do you expect" type comment after a raved about wonder product fails in the real world.

Cheers Brett

[photohiker]

Before we jump the gun and start a Hilleberg vs the rest discussion out of this (again) I think it would be nice to hear back from the OP regarding the seams and the test.

Fear not, if the TT material routinely broke down in a few years, we would be hearing about it.

[Franco]

Just took this shot.

In there you see 16 L of water (16 kg...) . The "waterhead" is only 140 mm so much less than the fabric can hold but was afraid that my pegs would not hold much more than that.
I set it up this way because you can see the water inside. I might try another way so that I can put a higher column in it.
This was set up up yesterday at about 10 AM so it has been like this for about 24 hours.
Franco

[joseiri]

With my Tarptent fabric panel, I made sure the section of material did not have any seams and it was the least folded part of the tent with no visible flaws. The material started to seep water immediately with many tens of drops slowly forming under the one litre ball of water .

I noticed that with the bought silnylon fabric I also tested that feeling for water penetration appeared to make the seeping worse.

[Franco]

Joseiri

I could be wrong but I think that what you observed is not "seepage" but condensation forming on the outside.
Have a look at the shot that I took a few minutes after I set it up yesterday. The fabric was warmer than the outside temperature, as I was pouring the water in (2 L at a time waiting for a possible collapse...) those droplets formed.
I then wiped them off and it remained dry since on the outside for a full day and night. Still there now...
Franco
The droplets are harder to see at the bottom but there are there

[joseiri]

Condensation should only occur on cold surfaces and particularly on humid days. What I observed was fairly rapid build up of droplets(beading) on a warm afternoon when there was no possibility of condensation forming. Water was defitinely seeping through the silnylon fabric and it only occured below the water line.

[joseiri]

Thank you Orion, those articles by Jim Wood on the jwbasecamp.com website are very instructive. He has had many a silnylon product bead water I see.

[sailfish]

If the water your puting on the fabric is below dew point, you will get condensation.
I think that to improve the validity of your testing, the water column has to be maintained above air temperature. That will ensure the underside of the fabric is always above dew point, eliminating any possability of condensation for the readers here.

Regards,
Ken

[joseiri]

As suggested in have now tested the water hoding property of my Tarptent cover and the recently purchased silnylon fabric using luke warm water (about 35 degrees) so as to avoid any condensation forming on the outside.
Within 15 minutes droplets of water started forming on the outside of both and growing to a point were they fell off. A new droplet would start forming at the same point immediately indicating that both fabrics seemed to have many tiny holes throughtout. I wiped away the droplets several times and they kept forming. I have formed the impression that both fabrics are not waterproof.