View Full Version : JRB Weathershield Arrival!

12-11-2004, 17:27
Just got back from holiday to find the Jack's R Better Weathershield awaiting me.
It's basically a rectangle of waterproof breathable fabric, with attachment points and draw cords. I set it up last night under my HH explorer with no bottom insulation. It felt much warmer than the bare fabric of the HH. After a while the cold started to seep in so I put a 1/2 length blue foam mat in between the undercover and the hammock- perfect for spring (In Australia) temperatures.
I believe I'd be able to get away with this settup for part of the year, and my JRB Nest underquilt in the colder months.
The set also came with the overcover, which is another rectangle sewn with a footbox. The overcover slides over the quilt or bag and increases the warmth quite a bit. I have not tried it yet, but I believe it could be used as a form of half-bivi under a smaller tarp for ground use, to provide protection from slashes.

12-11-2004, 23:52
Reading the info on JackRBetter site, I'm not quite sure about the setup. I think there is about 3 ways of using it during different times of the year. I take it that it can be used with the JRB Underquilt and then the weathershield on the outside. I'm wondering how much these 2 together will add in warmth. The cover which is to be used in case of fog or heavy dew leaves me asking a few questions. Is this to be used inside the hammock to cover a quilt or sleeping bag? If so, then it seems the outside of the bag will get just as wet from the water passing thru your sleeping bag. On a cold and foggy night, I used a VBL on the inside of my sleeping bag and used a VBL on the outside. In the morning, the outside of my bag was very wet. The VBL on the inside of my bag was full of water from sweat. The inside of my sleeping bag was dry so no vapor passed thru the VBL. I stayed warm all night, but if I was on the trail with a down bag I would have been in trouble.
Condensation, dew, and the cold are some tough problems which face hammock hangers. I would love to hear, if this overcover works...

12-12-2004, 01:00
Just looking at the color, I wonder if it's provent that the DriDucks are made of. You might could make a DIY using layers of Neatsheet at Walmart.

12-13-2004, 19:49

There are several different ways to use the JRB Weather Shield. It can be used as a system or the individual components (top and bottom) can be used separately.

The one thing it is not is a vapor shield – it’s breathable. I often see posts here and on Yahoo’s hammock camping group where folks wear rain suits as vapor barriers. This only works for the non-breathable models. When folks talk of using Frogg Toggs as a VB, they miss-speak because Frogg Toggs are breathable. They do add warmth but they can not be effectively used as vapor barriers. Recommend that any one seeking a good education on vapor barrier theory and technical issues study the Stephenson site.

The JRB Weather Shield should be thought of as an outer protector like a Garlington Taco or the Hennessy Super System with the notable difference that it is breathable. It is designed, as are all of the Jacks ‘R’ Better under quilts, to provide necessary protection without encasing the peak corners of the hammock. This virtually eliminates the condensation issues of fully encased non-breathable alternatives. It can be put on or taken off while the hammock is hanging which provides additional hassle free trail-side options. For those who use the extreme UL approach of a poncho tarp, the bottom can be removed and worn as a rain cape while the poncho continues to protect the hammock and gear.

It is much more flexible for use across the temperature spectrum than a HH Super System, because like all of the JRB quilts the "Windows" can be opened for ventilation while the vital organ area can remain protected. Again, it can be put on or taken off in under a minute while the hammock is hanging.

The JRB Weather Shield bottom when used alone weighs 7.7 oz and requires a JRB Suspension System of 1.9 oz for a total of 9.8 oz. This compares to a silnyl taco of approximately 7 oz plus the draw-up cord and the advertised weight of the HH Super System bottom of 7.5 oz (without the pad?). The JRB Weather Shield is the only one that is both waterproof and breathable.

The JRB Weather Shield top fits directly over quilts and most sleeping bags. It Provides bivi sack like protection, water proof, wind proof yet breathable. It can be used alone by the light and fast summer extreme UL as a sheet during appropriately warm weather either in a hammock or on the ground. This is a nice option when the temperature is in the 80s-90s and the humidity is matching for those who like something over them. Its generous 54" width allows it to be easily tucked in on the sides and remain tucked in better than narrower quilts alone if used by a ground dweller. The additional width is also a nice feature in cold weather when used with a quilt to reduce drafts from the quilt shifting. The top alone weighs 6.7 oz.

The JRB Weather Shield should provide an additional 6-10 degrees of temperature range to the family of quilts or any bag. This provides an economical and flexible means to extend the range of the sleep system carried. It reduces risk of an uncomfortable night for those using lighter quilts and bags during unexpected temperature drops. It also provides additional protection for those using tarps without the full weight and full protection of a bivi sack.

We have been testing several versions of this system since April. ncmtns got one of the earliest prototypes made of 3M Propore at Trail Days last May. He has posted of its effective value and his considerations to add insulation on this site.


12-13-2004, 21:05

... I often see posts here and on Yahoo’s hammock camping group where folks wear rain suits as vapor barriers. This only works for the non-breathable models. When folks talk of using Frogg Toggs as a VB, they miss-speak because Frogg Toggs are breathable. They do add warmth but they can not be effectively used as vapor barriers. Recommend that any one seeking a good education on vapor barrier theory and technical issues study the Stephenson site. ...

That might have been me saying that I wear my Frogg Toggs instead of using a vapor barrier liner. The way I see it, Frogg Toggs are breathable and while they may not be vapor barriers in absolute terms, they do significantly restrict vapor transport and you get the same effect, but maybe not to the same efficiency. If you overheat while wearing them you will notice the prespiration/sweat and either vent or reduce insulation. It makes sense to me to use my Frogg Toggs instead of a separate vapor barrier liner when the temperatures start dropping since I carry them anyway for rain protection.

The Stephenson paper on vapor barriers is very interesting. I have read it a few times and each time I pick up on more of what he is saying. You might have forgotten this comment from his paper about breathable fabrics:

"Obviously wicking underwear can’t stop chill of moisture evaporating from within your skin (misnamed insensible “sweat”), since that moisture is not on the surface where it can be wicked away. The ONLY way to reduce that evaporative chilling is to raise humidity next to your skin by raising humidity in surrounding air (limited to dew point in that air), or by retaining humidity with vapor barrier (VB) next to the skin. A VB that blocks 95% of evaporative heat and water loss is excellent. (Goretex will block 97%. They call that 3% loss “breathable”)."


12-14-2004, 10:00

Like you I use my breathable rain gear (O2 Rainwear) on occasion with the same logic and effect that you mention. My post comment was to distinguish it from a true VB, at least as I understand it from Stephenson and some other readings. Most of the time on AT conditions this is a good approach...It could , however, mislead someone needing true VB as in extended artic conditions to keep the moisture from ever getting into the bag. I read somewhere of an Iditerod rookie whose 9 lb artic bag was like 46 lbs and non packable at the end of the race. Extreme example but illustrative of the risks of evaporative moisture.

Point of the post was that the design of the JRB WS is as an outer cover, more like a two plane bivi. I would agree, on reflection, that while not a true VB it could be employed in that mode also. Raingear would probably be more effective as using the JRB WS would not encase as closely. Given these points and the gear discussed as available the maximum protection system would be; raingear, hammock, under quilt(s), JRB WS bottom, top quilt or bag, JRB WS top.

12-14-2004, 10:24
Peter Pan,

We agree, I thought you had forgotten that while the term vapor barrier is absolute in that it doesn't pass any vapors, it is also sometimes applied (maybe not correctly) to items that are 'almost vapor barriers' and work nearly as well as a true vapor barrier.

I think there was also a '46 lb bag story' in Stephenson's article. Along those lines, I read a comment recently on one of the web sites I frequent where someone said that in the mornings that they stuffed their sleeping bag as soon as they got out of it to exhale the warm humid vapor out of the bag before it could cool and condense. I also do that, but because it is just the order I do things in the mornings. Seems like it might help to some degree, what do you think... I think if it is cold enough some of it will have already condensed in the outer areas of the sleeping bag, but it might help some? Seems like I had also heard that you wanted the bag to breath a little bit to get the moisture out before you pack it, but what is going to make it breath on cold mornings?


12-14-2004, 11:07

I'm normally an air my quilt guy while I fix breakfst etc....but this cold weather issue is worth thought....Seems to me that at 32 and above there is some value to 10 minutes or so airing out...below that, perhaps the pack ASAP is better...I don't know....But it dawns on me that since my JRB quilts are wearable as a cerape and that they can be worn loose or tight that if I wear them loose while fixing breakfast that I will get the evapoative value plus some warmth on a cold morning. This passes my initial thought test... will have to try the loosening up approach....toughest point is that on a couple day winter weekend the minimal evaporation is tough to measure...will try the scale at home trick and evaluate any net weight difference.... also this test plan can be ruined if it is soooooo cold that I keep the cerape tight and warm. :D

12-14-2004, 13:19
Peter Pan,

Thanks for the answers to my questions. He does clear up many of my concerns. You said that you've tested this overcover since April. The dew is my biggest concern. As you know I plan on returning to finish my thru hike in Feb and I'm looking to stay warm and go lite. I really like your weathershield. Just a few questions here.

1. In what conditions was it tested? (In Brief) I mean, in a hammock, tent, ground, tarp, all of the above.

2. Will it fit on my 9 ft HH Explorer Ultralite A-Sys?

3. The JacksRBetter Nest or a closed cell pad would go under the weathershield?


12-14-2004, 16:46

Testing has been limited to ncmtns's use and about 6-7 nights of our own use of a variety of early prototypes. All has been with hammocks. Personally, I used one with my extreme light quilt set ( 1.5 " thick underquilt and 1.5" top quilt) to 32 degrees on Bear MT in NY in April. I was comfortable but just barely. I think it is fair to think of this as a summer light and fast option, or a range extender and and extreme weather (fog and wet) weapon. As a range extender 6-10 seems like a reasonable planning factor.

Yes, it will fit the Hennessy Explorer.

For your early start to finish your thru hike, going North out of HF as I understand it, you will need an underquilt or pad. And, yes the JRB WS is designed to hold one or two JRB quilts or pad

Hope this helps.

12-14-2004, 18:09
I met Peter Pan at Trail Days last summer and immediately saw the benefits of his Weather Shield proto type. He was kind enough to sell his only proto type at the time. Just wanted to put a plug out that Im extremely happy with it. I put it under my quilt system whenever I want to add another 10* plus or minus to my sleep system. Also if I suspect driving wind or heavy dampness I bring it with me. Its a very light weight addition with a heavy weight advantage. I have yet to have any condensation problems using the Shield.

I didnt know JRB has a 'bivy' for the top quilt now. Im for sure going to get one when I can build up my money from spending it on Christmas.

12-15-2004, 14:47

OK, so who has not read the Stephenson site? :)

I have read the site and I'm not sure what is opinion and what is factual on that site. One quote from the site which is sticking in my head right now is as follows; "Goretex (which is as good a vapor BARRIER as urethane coatings), was removed from use on bag exteriors because it CAUSED the bags to ALWAYS get WET. "

Do you think that this applies to the overcover?


Craig Wilson

12-15-2004, 16:45
Don't know what their issue was with gortex... Could have been that unless taped the baffle seams would cause leakage?? Lots of bags with goretex outer covers.

The JRB Weather Shield does not have any central seams which would be a leak issue.

12-15-2004, 20:17
I have read on http://www.bushwalking.org.au/FAQ/FAQ_Ultralightweight.htm , Gore used to use the famous teflon membrane as the waterproof/breathable fabric, with another layer of fabric over the top to protect it. This breathed well but clogged with dirt/grime easily.
Apparently they have for quite a while been using the breathable PU coated nylon as the waterproof/breathable membrane, with another layer of fabric over that.
I think that Stephenson was saying goretex made bags wet because the goretex does not breathe nearly as well as 1.1oz nylon or taffeta, so that little backlog of moitsure the fabric couldn't deal with would affect the down.
Hopefully I haven't just been rambling here...
I can't see this happening with my JRB weathershield topcover- The top cover could easily be rolled back or untucked to allow moisture to escape in high humidity. Also, the underside has the "fluffy" Goretex nexus type feel that allows any moisture to be absorbed into the underside of the fabric until it can be transported to the other side, as opposed to absorbing into your sleeping bag.

12-16-2004, 11:00
Add a silnylon bottom and a hood some sort and the Weather Shield "top" would be a great standalone bivy.

So, what exectly are the specs of the "top"? Does it have a foot pocket, or is it just a rectangular sheet of Propore, with hem around the edges?

12-16-2004, 11:28
Moisture buildup in sleeping bags is talked about in many different references. Stephenson, Jardine, Wiggy, and most anybody that talks about using sleeping bags has something to say. My understanding is that anything that restricts vapor transport can affect moisture buildup due to insensible or sensible perspiration. In very humid conditions even something as breathable as no-see-un netting can contribute to moisture buildup in tents, sleeping bags, etc. Conditions vary, you need to deal with conditions as they vary and make adustments as best you can. The WeatherShield is one of those pieces of equipment that you would use when it is appropriate and not when it isn't. You don't always wear your wind jacket, you wear it when you need it. If a wind jacket is breathable, it doesn't mean you won't get soaking wet from perspiration if you wear it at the wrong time.


12-16-2004, 16:04
I can't see this happening with my JRB weathershield topcover- The top cover could easily be rolled back or untucked to allow moisture to escape in high humidity. Also, the underside has the "fluffy" Goretex nexus type feel that allows any moisture to be absorbed into the underside of the fabric until it can be transported to the other side, as opposed to absorbing into your sleeping bag.
Thanks for the input. This sounds like something I could use.

12-16-2004, 21:34
Yellow Jacket,

I Knew you would appreciate the value of Microporous Polypropylene....you're right...it rocks.

Finished size is 79x 54... it has a sewn in foot sack across the bottom and up the first 24 inches.

12-18-2004, 21:08
I was a little confused so I did some research and found the info I was looking for. The info I am going to post comes from the member area of www.backpackinglight.com (http://www.backpackinglight.com/) thus, I am going to make sure that I give credit to them.

In regards to condensation www.backpackinglight.com (http://www.backpackinglight.com/) says:

"Many of the single-walled (silnylon) shelters condense more moisture on their walls in cold and humid conditions than do heavier double-walled shelters (conventional tents). To protect your sleeping bag’s insulation, if it isn't made with a highly breathable water-resistant shell of silicone-encapsulated microfiber such as EPIC, you might want to encase it in a bivy sack with a top shell of such a fabric. An excellent example of this design is Oware’s EPIC/silnylon bivy sack(reviewed in this issue). It provides enough protection from drips and inadvertent splashes under shelter walls, or rain blowing under a tarp, but under most conditions it will not inhibit breathability and so promote condensation enough to compromise your sleeping bag’s insulation."The following summation is from www.backpackinglight.com (http://www.backpackinglight.com/) :

"Polyurethane only fabrics and bicomponent PTFE fabrics (i.e., those with a hydrophilic PU membrane like Gore-Tex) breathe better at higher humidity levels. In other words, they transport moisture better when it’s warm and moist inside your garment."The following summation is from www.backpackinglight.com (http://www.backpackinglight.com/) :

"There is a new class of WP/B breathable fabrics with hydrophobic micro-porous membranes like eVENT, Propore and Entrant G2 XT that breathe better at all humidity levels than the best Gore-Tex fabrics. These new fabrics are extremely breathable even at lowhumidity levels, unlike Gore-Tex. They start venting before it gets warm and clammy inside your garment. According to some researchers, the enhanced breathability of these fabrics may increase your comfort over conventional Polyurethane and PU/PTFE fabrics like Gore-Tex."I don't know if the above info helps anybody other than me but, I thought I would post it FWIW.


Craig Wilson

12-19-2004, 00:13
Who better to make hiking products than hikers themselves.
Jacks-r-better bettered hammocking for all HH users with their Nest.
I'm sure their WeatherShield will better the Supersystem of Hennessey because like i said they are hikers.
Though I'm off the trail for a while with foot failure I am excited to compare and contrast the two systems.
Probably wont see the WeatherShield until next year but as soon as it gets here I'll contrast the two and post my impressions if any are interested.
Since I'll have both then, La AquaNa will probably benefit from the new addition, if she's not interested I'll pass one of the two on to Shaka.

SGT Rock
12-20-2004, 09:06
I would like to get a WeatherShield and a SuperShelter to try them out side by side sometime. This last hike I saw the benifit.

12-27-2004, 03:36
i just placed an order for a jacks r better undershield a couple days ago,i have recently added a jacksrbetter 8x8 silny tarp to my hh ultralite hammock,also ordered the jacksrbetter python skins and 2 compression sacks.no more sleeping on the ground for me.:sun neo