tarptent rainbow condensation issue

A couple of questions about condensation in rainy weather and protecting gear.


Here's some background...went out for two nights, leaving the tent set up in the same camp for both nights. There was a light rain on the first night with temps in the low 40's/upper 30's. There was a bit of seepage if I touched the sides of the tent. It rained from 10am the second day until about 3pm and then started back up around 8pm and carried on through the next morning when we borke camp again low 40's/upper 30's. Sometime in the night I started getting misted on. No leaks, just a light mist that covered the entire inside of the tent by morning. Is this common? Is there anything in particular I can do to keep my bag dry without adding alot more weight? Or am I making too much of it?

I'm new to foul weather backpacking so any tips would be appreciated.

Thanks!
Millette

Me think you just got baptised into the Church of Tarptent.

There are two reasons for misting under silnylon :
1) the rain is knocking the inevitable condensation off the fly . ( This happens with double wall tents as well , but often enough it means that the top of the inner gets wet).
To remedy ,wipe the top down every few hours. I keep a kitchen cloth handy for that.
2) when the rain drops are big enough to hit the fly at a speed that exceeds the waterhead (1000-1500mm for this type of silnylon) some drops will penetrate causing the misting.
With cause number 2 you can also get number 1 as a bonus.

With a double skin tent once the top of the inner gets saturated it will drip on you and there is nothing you can do about it...( not quickly/easily)

As a suggestion, to minimise No 1 , keep the (mesh) door open if you can.

BTW, you are much more likely to get the bag wet from touching the walls than from misting. Most sleeping bags can cope with the occasional spray.

Franco

I am not familiar with the Tarptent but it has good reputation so some users may chime in. All tents can experience condensation, especially single wall tents. This is why I prefer tarp. On double wall tents the condensation attaches to outer wall and drips down to ground. On single wall, the condensation should drip down wall but if it's raining or windy the condensation can drip on you in tent. Not good esp. if you have down bag.

Condensation can be caused by bringing wet gear and clothes into tent, moisture in breath, sweating and evaporation of water from skin. Add two people to tent and you have double the trouble.

In conditions you described, if no wind and high humidity, condensation will be something you will have to control by wiping it off tent with a small towel if you wake up getting dripped on, or control a big reason which is sweating and evaporation. To control sweating which causes a lot of condensation, simply make sure when you sleep you do not overheat and sweat. Better to layer than take off if need be. For normal evaporation, a vapor barrier could help but will probably be uncomfortable over freezing temp.

Under my tarp in VERY wet weather, I will use the Bibler Winter Bivy at 9 oz. to keep spray off my down bag if needed. Howevery in tent if your sleeping bag is wet it is probably more from you sweating and evaporation wetting the bag from the inside out.

Chuck

Yes. A couple years ago in Yosemite, using my floorless Squall, there were snow pellets before dark, then more after I went to bed. It froze overnight, then warmed up again before sunrise. More pellets before light which knocked the condensation off the walls. Like a drizzle all over my clothes and bag. I was at a point where I could bail, so I did as it didn't look like it was going to be nice enough to dry my gear out. Just about the same this fall, different tent, with the rain drops causing me to get spritzed. My gear was a little drier this year and I stuck it out. Third day out was beautiful, well worth a day of snow/rain.

I'd say the mist is coming from wind or rain hitting the tent and causing condensation to fall off inside. It's pretty normal with tents like the Rainbow that don't have a separate tent & fly. I try to deal with condensation by getting all the airflow in the tent that I can get away with without getting cold. You can also dab moisture that's pooled up by using a bandana or handtowel, which people often carry with them anyway.

Most modern sleeping bags come with a water repellant coating. How much this actually helps, I don't know.

There are a few things you can do to help with moisture after it's happened. I shake off all the moisture I can before packing it up, and if weather & time allow I'll sometimes pitch the tent during lunch so the sun can dry it out.

I used to get annoyed at how small items like glasses, camera, etc. would get moist overnight. Then I discovered that I could use my little raingear stuffsacks to protect my valuables. They get packed along anyway, and they work fine.

Keep backpacking and you will have lots of experience with foul weather.

Usually I'm either in a hammock or double wall tent. Both have ventelation and I don't experience the problem unless it rains for days. With a tarp tent or single wall I would ventelate. Phat suggested in another post that using a candle lantern helps with this problem. Phat, care to chime in?

Can't comment on it for summertime/rainy type things - My experience doing this is in the top of
a top vented tent in bitterly cold subzero weather in wintertime. Hanging a candle lantern up high
that burns all night helps warm up the top a bit and keep the air moving out of the vents which tends to cut down on the amount of frost I have on the inside in the morning. In theory this
would work in summertime too, but I wouldn't justify the weight of the candle lantern because
it's just not enough of a problem then.

Summertime I just make sure I'm well vented and it's ok. yes there is sometimes some condensation on a cool rainy night/morning. I do carry one large cotton hanky when backpacking
for situations just like this. (my cotton hanky is a large piece of a dead cotton T-shirt that
rides in my pocket.)

Your are in ideal weather for condensation in any shelter with high humidity and no wind. Moving air is what keeps condensation out of your tent, but if no air is moving by wind, and what air there is is high in humidity that's a condensation breeding ground. Ventilation is what moves air through your tent. The double wall or fly over a tent is supposed to create and trap a pocket of warm air that will assist air flow in your tent. That does not exist in single wall tents. Also that "warm air gap is often non-existent in double wall tents especially in weather as you described. Read steps 7 and 8 for the theory explained at warmlite:
http://warmlite.com/tents.htm

I also use the TT Rainbow. In addition to the various comments others have made, I've found that it appears to help if I sleep with my head/mouth facing the door and as close to the door as possible, rather than more in the middle or far side of tent. This vents my breath directly out of the tent. Not certain, but this does seem to help. I also try to sleep with the fly either fully or partially opened as much as weather will allow. Also, trying to pitch the tent so that the long sides rather than the ends are facing into the wind helps with air flow into and through the tent (of course, assuming the wind isn't too strong or there's not a problem with cold).
Gerry Magnes
Schenectady, NY

As Franco and Chuck both said, wiping off the inside of the tent is, for me at least, the fall-back solution. Ideally one is fortunate with the weather and/or pitches the tent in the optimal place to minimize condensation, but unless you live in a pretty dry climate, condensation is going to happen. I live in the Pacific Northwest, and arguably, the lightest double wall tent might be better here, but at least in summertime I'm willing to risk a few (or even continuous) wet days in favor of a lighter tent.

The little pack towels are pretty amazing. Part of the cost for me of saving a little weight is to be willing to wake up in the middle of the night and repeatedly towel off part of the inside of the tent and then ring out the towel. Rinse and repeat. Not to try to get it bone dry inside, just to reduce the accumulated water level to the point where not much is dripping on me.

The little pack towel is helpful in the morning too for those cases where I'm not in a hurry and it's not currently raining --- wiping down the outside of the tent before taking it down means carrying less water weight during the day, and putting up a somewhat less wet tent that evening.

The smallest MSR Packtowel is listed at 21 grams (0.7 oz) and costs $10. Also helpful for drying off after washing yourself (I used mine multiple times at campground showers on the PCT this year).

Thanks everyone for your information and suggestions.

I'm loving the Rainbow so I'll just pack a small camp towel for condensation issues.

Millette