DriDown sleeping bag Versus Synthetic bag

[jimyjam]

I am planning a NOBO thru hike of the Appalachian Trail in 2016 and have struggled with the type of bag to use. I will be using a hammock with the warbonnet superfly tarp as my shelter. I am leaning towards the Kelty TraiLogic 20 SB which uses DriDown filling with a waterproof hood and foot box. I'm concerned with the possibility of the sleeping bag getting wet rendering it mostly useless.
I am sure this has been asked before and am sorry for the repeat (so please no "irritated" responses) but I dug pretty deep and couldn't find a post concerning this topic.
DRIDOWN VS SYNTHETIC
Any advice is appreciated. What was some of you're experiences as you thru hiked the AT?


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[Wise Old Owl]

There are not many threads or posts as this is a recent addition to the hiker community. Dri-Down is a electrostatic coating on a electron level of an added electron to repel the water molecule. It is not a chemical spray. It doesn't appear to be silicone related. Therefore it compresses and repels water - it will resist sweat and moisture from your feet - but might not wick thru the bag. It may be the last bag you purchase for the rest of your life and if you take care of it.. you may be able to hand it down.

[MikeN]

I recently purchased a Marmot Helium 15 bag, which has down coated with Marmot's "Down Defender." I think "Dri-Down" and "Down Defender" are similar processes that come under the generic term of "hydrophobic down." Because the down is coated and it's next to your body, especially your mouth and nose where you inhale, I was concerned about any health risks. However, Wise Old Owl, you say the down coating is electrostatic and not a chemical spray. Would that also mean it's probably not a health risk? Also, would you know if all the various hydrophobic down processes (Kelty, Marmot, Sierra Designs and others all have their own names for it) use an electrostatic coating? I would assume they do since it's probably the same technology. Thanks.

ColinsDadMike

[dmax]

DriDown uses a molecular level polymer. .. I think I read on BPL that the new drydown (might have been a different brand) won't last as long as a regular down bag. How they came up with this, I have no idea.

[HooKooDooKu]

From the time I've spent here in the WB forums, I'm under the general impression that for the bulk of the AT, a regular down bag is just fine, you just need to make sure you don't let it get wet (such as a water proof stuff sack).

I personally do the bulk of my hiking in GSMNP. The place is so damp, there's almost never a campfire ban (save for places people start cutting trees down for fire wood), and once something gets damp, it stays damp until some external heat source can dry it. My older brother has even stated that in the GSMNP, a down bag will absorb moisture right out of the air. So for a place like that, you would want to look into dry-down or synthetic.

I currently only own synthetics, and based on my research and limited experience, the Mountain Hardware Ultralamina series seems to be THE BEST synthetic bag available. Its weight and especially its compressibility is on par with some down bags. A 32 degree bag will only weight 2lbs and comes with a 6x10 stuffsack, while a 15 degree bag will weight 3 lbs and comes in a 7x13 stuffsack. Full price, these bags cost around $250, but can easily be found for around $180 (or even less for model year end clearance sales).

[Venchka]

I have never spent a night in a hammock. Therefore, I know nothing. I have researched the subject. Folks who do know about hammocks use a top quilt and an under quilt.
We do need more facts. Are you a hot, normal or cold sleeper? When do you plan to start?
Maybe you need to ask different questions.

Wayne


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[rickb]

There are not many threads or posts as this is a recent addition to the hiker community. Dri-Down is a electrostatic coating on a electron level of an added electron to repel the water molecule. It is not a chemical spray. It doesn't appear to be silicone related.

So it is a coating but not a spray?

Not sure I grasp the importance of that distinction. If something is added to the down, that something will be a chemical, correct? If not a chemical, what adds the extra (albeit very trivial) weight.

The manufacturers have not shared anything that most of us can understand regarding exactly what goes into their respective products. They talk about process, but not what is used in that process.

[colorado_rob]

So it is a coating but not a spray?

Not sure I grasp the importance of that distinction. If something is added to the down, that something will be a chemical, correct? If not a chemical, what adds the extra (albeit very trivial) weight.

The manufacturers have not shared anything that most of us can understand regarding exactly what goes into their respective products. They talk about process, but not what is used in that process.

When this stuff first came out a couple years ago, I was excited. I then read some less than great reviews and have cooled my heels and haven't yet pulled the trigger on a bag with it. Here is a quote from the zpacks web site:

"Real world results are harder to observe. The WR treatment should be seen as a minor benefit. It does take longer to wet out, but it will still become soaked and clump up if given enough time. You still need to be careful to keep your bag dry".

Personally, even though I have always worried about it a bit, I have never once had a down bag get wet enough to make any difference, and I've slept in a down bag a couple thousand nights. If I needed to buy a new bag anyway (but: I have 6 bags of various temp ratings), I'd probably go with Dri down, but can't justify replacing my perfectly good bags at this point with it.

[Venchka]

While this latest Silver Bullet may (the jury is still out on that claim) slow the loss of loft due to water vapor, liquid water will turn down into a useless lump. As for the waterproof fabric on the ends, why bother? That will only trap more water vapor inside the bag.
Most good down bags have a dark fabric on the inside for a reason: You turn the bag inside out and bake it in the sun whenever possible.
The new Kelty 20 SB is in 3rd place on my short list of new bags to consider. Not for the Dri Down, but because it is a $300, 2 pounds & change, more or less 20 degree bag. #2 is The North Face Hightail 3S and #1 is the Western Mountaineering Ultralite. All of these are under consideration for use in tents. I don't own a hammock. If I did, I would be looking for a pair of 0 or 20 degree quilts.
Like these: http://store.enlightenedequipment.com/
Or these: http://www.jacksrbetter.com/quilts/

Wayne

[colorado_rob]

... and #1 is the Western Mountaineering Ultralite. ...

Just an FYI if you don't already realize this: My wife owns the WM ultralite, great bag, conservative 20 deg rating, and I borrow it occasionally when I want the absolute minimum weight and I'm only out a night or two (and need that 20 deg. warmth), but the girth on this bag is too tight for me. I own/use the WM Alpinelite, also a 20 deg bag, but much more girth, and of course, about 6 ounces heavier. Make sure you are actually comfortable in a small girth bag before pulling the trigger on the Ultralite model.

[jimyjam]

Venchka thanks for the info and your input. I am a hammock sleeper and many do use under and top quilts but not all. I have the cold bottom syndrome all worked out and I have the temperature rating I will need for my comfort level all figured out. I am just interested in my options of sleeping bags. I am not interested in a top quilt as when I camp with my spouse we like to sleep together and hammock sleeping in that instance doesn't work so I'm on the ground. Also, I don't want the extra $300-$400 expense and space consumption of an extra bag.
I want to thank all of you for your info...it truly is priceless


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[jimyjam]

Venchka thanks for the second message....some great info


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[Venchka]

Just an FYI if you don't already realize this: My wife owns the WM ultralite, great bag, conservative 20 deg rating, and I borrow it occasionally when I want the absolute minimum weight and I'm only out a night or two (and need that 20 deg. warmth), but the girth on this bag is too tight for me. I own/use the WM Alpinelite, also a 20 deg bag, but much more girth, and of course, about 6 ounces heavier. Make sure you are actually comfortable in a small girth bag before pulling the trigger on the Ultralite model.

Thanks Rob. You have mentioned that before. I do know about the girth. The Ultralite is very similar to my current 3 season bag. I have tried on the Ultralite locally. Snug, but I am used to the fit. Not perfect but for me it is better than the Alpenlite. I also have the slightly larger Antelope. The girth of the Antelope / Vistalite is perfect for me. I wish WM offered that size bag in more temperature ratings.
Thanks for your help.

Wayne


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[Venchka]

You're welcome. Always glad to try and help.

Wayne


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[Just Bill]

My understanding-
Won't help much with a full wet-out or beat synthetic in that regard. If you are not confident you can solve this problem (or overcome it if you mess up) then skip the down.

What is interesting, in the newer "super down" 900 fill power stuff it has a place IMO. Although it appears to cause a 50 fill power reduction during the application.
Generally- out west- down is king, out east- high humidity makes synthetic superior.*
*(when talking super high fill power and assuming all else is equal- including your ability to handle down properly)

The 900 fill stuff is so fluffy and downy that simply going from the house to the summer humidity can drop the fill power. Make it a multi-day trip on the southern half of a trail like the AT and it will never quite dry out. So while the 900 fill ultralight bags have been impressively light, they fail, especially as they rely on so little down to do the job. When you have eight ounces of down you just can't cover the cold spots that occur with even a little moisture.

I could be wrong, but I'd be curious how many of you 10-20 degree down bag users out east would find them horribly hot out west. I am a warm sleeper, but when I find myself happy in a synthetic rated 20 degrees lower than a campmate with down- there has to be something to the humidity arguement. Western folks seem to routinely use lighter down bags than their eastern counterparts with humidity being the only real difference in the equation- but maybe some here can back that up better than I. This issue is why more and more winter folks are using vapor barrier liners. If just your bodies humidity can cause 25% or more loss of fill in the relatively dry cold then it stands to reason the same issue would be found during the rest of the year on the AT (I know there's more to VBL than that)

What is exciting- the dri-down is still down- but if it solves the humidity creep problem then it may put those 1lb 32 degree bags back on top for humid regions. I pulled the trigger on that sea to summit bag to find out myself. I would happily use and pay for this feature of dri-down- if it reduces humidity creep I'll be happy- otherwise back to synthetic.