Siltarp tent noob question

Posted by: urbansix

Siltarp tent noob question - 04/13/08 06:41 AM

I have a silnylon tarp shelter, bug liner & poncho that I received used, but have not tried them out in "real life" (well I have been using the poncho on trips to double as a footprint) because I didn't have trekking poles to set them up with. Until now.

I set up the tarp shelter with bug screen yesterday in the back yard, and it ended up staying out all night, with nobody inside. This morning it looks like the dew has collected on the inside surface of the tarp. Is it normal for moisture to wick through, or is it collecting on both sides of the fabric? Are you supposed to waterproof silnylon in addition to the way it comes - silicon-coated? I don't know how much use it got from previous owner, but it looks like it may well have gone unused.
Posted by: phat

Re: Siltarp tent noob question - 04/13/08 10:26 AM

Some condensation on the inside of a single wall tarp/tent is normal - especially when there is a large temp drop at night.

You don't typically need to waterproof silnylon, although most things made of it do not come seam sealed (meaning water can come through the thread holes where it is sewn). If you wanna seam seal it go buy a tube of mcnett's "silnet" seam sealer, or mix up your own from 1/2 GE clear silicone sealant, and 1/2 white gas, and paint it on the seams with a small brush. However, from your description, it sounds like what you were seeing is condensation from warm moist ground and cold air overtop.

As far as condensation goes, you attempt to minimize it through ventilation, and keep a small towel or hanky to wipe off the inside. (I take about a 1 foot square piece of old cotton t-shirt on all my trips to act as a handkerchief and wiper - some like bandanas, etc.). With anything single wall remember the tighter you are buttoned up with less ventilation, the more condensation you may see.

Note, you might want to tell us what make of tarptent/bugnet and poncho it is if you know. It's very likely someone here will have experience with your particular shelter.
Posted by: Glenn

Re: Siltarp tent noob question - 04/13/08 02:59 PM

Is this an Integral Designs Silshelter and Bug Shelter?

I've used one a little, and found that in spring and fall in Ohio (when there's still a fair amount of humidity, and a 20 or more degree drop in temperatures at night), you'll get condensation on the inside of that particular shelter - and also virtually any other shelter, including my Hubba, if you pitch the fly and don't leave sufficient ventilation.

I found that the condensation was minimized, usually to the vanishing point, if I could leave the vestibule flaps wide open. Like Phat said, ventilation is the key.

However, I found that floorless shelters, pitched on grass, tend to have more condensation issues. (I always leave mine pitched overnight in the yard when I first get them, too.) I believe this has to do with the fact that grass also holds moisture and "breathes" on its own, releasing moisture - thus you have an additional source of moisture underneath the canopy. It's a source that, camped on forest duff, isn't there during actual trips. And, sure enough, in the field, the condensation was much less.

You won't be able to make the condensation go away completely, but don't form an opinion on the shelter until you've had a chance to use it in the field. I always thought the Silshelter was one of the better shaped tarps/single-wall shelters out there. The only reason I quit using it was that the Hubba is simpler, and because, if you need bug protection as opposed to a simple groundcloth, the Silshelter and bivy sack or Bug Liner weighed nearly as much as the Hubba.
Posted by: ohiohiker

Re: Siltarp tent noob question - 04/15/08 08:26 AM

Use at least a thin painter's drop cloth to cover all of the ground under the shelter. This should reduce condensation significantly.

Make sure none of the ground cloth is exposed from under the shelter, as it will act as a rain funnel to your sleeping bag. <img src="/forums/images/graemlins/crazy.gif" alt="" />
Posted by: urbansix

Re: Siltarp tent noob question - 04/17/08 02:54 AM

Quote:
Is this an Integral Designs Silshelter and Bug Shelter?

Yes it is. I've since added a few inches (6 - 12", adjustable) of extension to the tiedown loops, to raise it up off the ground a little more for ventilation. And SilNetted the seams. Have not tried it out that way yet.
Posted by: johndavid

Re: Siltarp tent noob question - 04/24/08 09:19 PM

I've used the SilShelter for at least a couple of weeks in total, almost always with a water and wind-resistant sleeping bag cover.

Condensation has varied based on conditions, been unremarkable, though certainly observable, and this in humid northeast.

When it's cool and/or windy, or in prolonged heavy rain, I try to keep it pitched with edges as close to the ground as possible and fold the weird & funky "door" shut as best as I can... This cuts the wind, conserves heat and/or minimizes "splash" from rain.

Undoubtedly this results in less ventilation and greater condensation but also I believe, greater overall comfort in nasty weather.

The sleeping bag cover can be a nice item in conjunction with any tarp shelter, and need/ought not weigh a pound. (When adding this weighty item, one can also use a somewhat lighter sleeping bag.. Sleeping bag and mat is protected inside the cover, which has waterproof floor, and I often dispense with groundsheet all together, though I've considered using a 1/3-size groundsheet.)

In general, I'm only somewhat satisfied with the SilShelter. It definitely does its job, and is very light. It's a bit cramped for much besides sleeping, and a zipper on the door would be nice.