Silnylon Hex Tarp Leaking - Solutions?

**hammockNQ** · 12-20-2010, 03:19

Thanks for all the ideas.

I have contacted Hennessy who suggested to look first at the seams. I have strung up in the backyard with some light rain and under daylight it is clear that there is a constant weeping through the seams coming in. So this is certainly a significant part of the problem and maybe the entire problem (though the water was coming in from all parts of tarp on the night - maybe this was simply the sheer volume of it running down the sides from the apex and going everywhere).

Suspension is definately not part of the problem - drip lines are working and suspension just inside the drip point remains dry.

I'll see what Hennessy come back with from here and keep you all posted as to the answer.

**Oxblood** · 12-21-2010, 10:38

All you need to do is seal the seam, and you should be good to go.

**mountain_man_mike** · 12-21-2010, 16:32

I haven't been in that sort of rainy conditions but I am wondering if a second tarp would help. That is one to handle 90% of the torrential downpour and the second to keep you dry. True, it's more weight but in the spirit of packing to cope with the elements perhaps it's worth consideration?

If sealing seams is all that is needed mixing mineral spirits with clear silicon caulk from a Home Depot type store in a paper cup then brushing it on with a cheap paintbrush has held really well for me.

Happy Trails...

**hammockNQ** · 12-22-2010, 03:09

Finally a dry day and a chance to test the tarp with the hose only.

Seems the issue is the seams. I had assumed that as the tarp is factory seam taped and also the volumes coming through the seams (was amazing - several cups in less than 2 hours) that this wasn't the major issue. Guess i was wrong (unfortunately not the first time!).

Under high pressure hosing the rest of the tarp showed no signs of misting (though i understand it can take sustained water pressure over time to happen?). Reading around the net it seems misting is a problem for some lessor quality silnylon and also ageing silnylon. But from my reading (you probably all know already) it appears silnylon is really like a highly durable DWR and silicon should be reapplied every few years to hold up to higher pressure water pressure. But for the moment, it appears to me that Hennessy used good quality stuff on this tarp based on the hose test.

If sealing seams is all that is needed mixing mineral spirits with clear silicon caulk from a Home Depot type store in a paper cup then brushing it on with a cheap paintbrush has held really well for me.

"

Exactly what i had planned from reading some other sites on silnylon. Also people are suggesting a 1:5 mixture painted over the entire tarp is good for restoring high water resistance to ageing or poor quality silnylon.

Thanks all for your help on this.

**hammockNQ** · 12-27-2010, 19:57

Ok, i have painted the seams and top 1m or so either side of the ridge seam (to be double safe for any possible 'misting') with the diluted silicone mix.

Works well - we haven't seen the intensity of the rain of the other night but still plenty of volume in the backyard and the tarp has not leaked and the hammock has stayed dry. Very easy project if anyone wants to reproof their silnylon.

As i understand it thhe hennessy tarp is seam taped but i guess the lesson is that it won't necessarily stay waterproof without further seam sealer.

**NCPatrick** · 03-19-2012, 14:55

Just wanted to resurrect this thread. I was out at Merchants Millpond State Park, NC recently, and the first night it rained hard for about 13 hours. I had the Hennessy hex tarp, silnylon, coyote brown, which had been my tarp of choice for some time due to the excellent coverage.

Middle of the rain storm overnight, I began feeling drips. The tarp had a definite leak on the seam. I had set up slightly off kilter of that seam, so only the right side of the hammock was getting dripped on. I used a 2Q underquilt protector rigged on that side to keep the rain off, but it was a good 5 hours more before the danger was past.

At home, I looked at the seam. It was taped, and not silicone sealed. The tape had gotten old, brittle, and translucent, and was peeling off the seam. I peeled the rest of the tape off and will have to re-seal that seam with silicone before I take it back out.

I was curious to know if anyone else had the same problem with this tarp. Or if you haven't, perhaps you might want to take a look at your taped seams before your next trip...

**jameyt** · 03-20-2012, 01:14

I used to camp there a bit back in college. Really love that place. Was camping there when a Hurricane was bearing down on us in 1992.

**FLRider** · 03-20-2012, 04:42

Thanks for the heads-up, NCPatrick! It's about to start being the rainy season down here in FL, and it definitely behooves those of us who go out in it to double-check our equipment.

**SmokeHouse** · 03-20-2012, 09:13

HammockHQ, I see you found your leaky seam... something else to think about that happened to me. My tarp is 1.1 Sil with doors and last year is rained so hard that everything felt wet. I turned the light on to see a light rain under the tarp due to the heavy condensation. I had a DryDuck poncho that I sewn some loops on each corner, so I attached the loops to each end of hammock. I then tied a string to the other loops and attached to ground under my tarp, so I had double protection from the misting condensation. This only happened to me once and was glad I had the loops on the poncho...
Since you have a 1.1 sil tarp and your area is know for alot or rain, You may want to look into something like this...