Seamless WPB Down Jacket

hi Aaron, I have been thinking about a different construction idea for down gear.

My plan is to use silnylon or 1.9 coated ripstop outer shell and 1.1 oz uncoated ripstop as the inner shell with a second silnylon or 1.9 coated ripstop flap inner. This gives you a totally waterproof garment so you never have to worry about your down getting wet. It fits very well in my system as I can wear down over my outer shell.

For seamless construction you glue silk between the outer and inner shell to make baffle walls. I leave upto you to judge the praticalness of this construction as I have never tried it.

Huzefa, The down may not get wet from the outside in, but what about from the inside out (i.e. body vapor)? I would think that a down jacket with a non-breathable external shell would be a sauna.

Hi Brian.

>The down may not get wet from the outside in, but what about from the inside out (i.e. body vapor)?
You can wear VB inside.

>I would think that a down jacket with a non-breathable external shell would be a sauna.

wouldnt that be wonderful? a sauna at 0F while others are feeling cold?

Aaron, another construction idea is to use silnylon or 1.9 coated ripstop for both inner and outer shell and add a valve to inflate and deflate. I had dismissed this idea long back due to simplicity of uncoated side+flap construction. But adding a valve means you can leave your sleeping pad at home as down wont compress by your weight. I dont know how confortable it will be but if you are willing to expriment, go for it!

Do you mean down or synthetic?

It seems to be a pretty cool idea, although i dont see the benefit of using a Houdini jacket over momentum for the shell. From what I gather, the houdini is just a DWR jacket.

A full WP/B jacket set up like this could be interesting, but you would need another WP/B jacket for when you would get too hot using the insulated one.

You could make a liner-only jacket for under a WP/B and have some of that light silk as a shell since it would always be covered with another jacket and have a momentum or silk liner. With the primaloft prequilt, it would probably come out to about 7-9 oz. 2 oz climashield combat from OWF Inc. Would probably be a better choice because of the lack of scrim and increased durability.

Could you explain more what the purpose of this jacket would be?

Huzefa,
you would need to make it from heat sealable taffeta or oxford for that to work. Silnylon, while waterproof, isn't going to be air tight under any pressure, and neither will the seams even if sealed.
If anyone has expertise with heat sealables, a valved, insulated jacket and pants could be a fun project/ science fair entry. Make it a 1 piece full body suit and you could leave your sleeping pad, bag, and tarp at home. You could roll around in your sleep and be fully cushioned and look similar to the michelin man. Also, it should be bright pink. The mental image of this I got has brightened my day.

Hey David,
The whole idea is to have down jacket that can take what ever you can throw at it.

My quilt constructed with this is 6.5 ounces of Momentium, 4.5 ounces from Pre-quilt and 9 ounces of 800 down.

The pre-quilt goes from 30" on bottom to 45" on top.

Since the quilt does not have any stitching on top there is no need for a bivy. You also don't have to worry about wetness under a minimal tarp.
Even in moist conditions, any amount of condensation or perspiration that gets caught, get absorbed by the pre-quilt and the down stays 100% completely dry.

The quilt has been unlike any other down bag I have used in keeping moisture from getting into the down and hence compressing it, loosing loft and getting cold.

Other than the 4.5 ounce weight penalty that adds nothing to the warmth factor, taking the bivy and all doubts about the ability of the down out off the equation is well worth it.

My thoughts on the down jacket is just that I think it would be cool to have the same capabilities in a nice warm winter jacket.
Anyone that would see the jacket would think it was synthetic due to the lack of stitching.

My only dilemma with the Houdini is that I don't think I could make it look that good using a thru-hike pattern with momentium on the outside.
The fabric doesn't have to be completely water-proof due to the synthetic layer as long as it breathes fairly well and will still hold up to almost any condition you can throw at.

Huzefa,
I have stopped working with 1.1 and 1.9 ounce Nylon since Momentium has come out.
It is far more superior for the purposes it serves.

David, I wasnt sure about silnylon too. But I think 1.9oz ripstop with a good coating will work fine for this application. It doesnt neccessarily have to be heat sealable. Heat sealable fabric have an additonal 3mm thermal plastic urethane coating. Thats why it is heavier. We need this coating only at the seams. Using both seam tape and urethene adhesive can give a very strong seam.

I may be wrong about this. May be it is the 3mm coating thats giving the air tight characteristic to heat sealable fabric. Anyone willing to test this theory? you only have to order some samples from seattle fabric or rockywood.

Another option would be to make the jacket directly from 3mm poly. That would be light!

>Make it a 1 piece full body suit and you could leave your sleeping pad, bag, and tarp at home. You could roll around in your sleep and be fully cushioned and look similar to the michelin man.

hey I am very serious about this idea :)

>I have stopped working with 1.1 and 1.9 ounce Nylon since Momentium has come out.
It is far more superior for the purposes it serves.

Aaron, I agree with you that momentum 'is far more superior for the purposes it serves.' But you want WPB jacket. Momentum is water resistant.

Yeah, but I'm saying that in retrospect that the down won't get wet. "WRB" Water resistant breathable, beter?

My bad

>I have been playing with the concept of a seamless down jacket that would be able to go through a down poor

> I'm saying that in retrospect that the down won't get wet.

Aaron, do you plan to use your down jacket only under a tarp/tent? If you plan to use it for say unsheltered rest stop or for a walk prequilt should eventually wet out in sustained downpour.

If what you actually want is WRB jacket with seamless contruction then a baffles stitched from silk to momemtum inner with momentum or houdini outer shell would be much lighter.

I'm not sure what kind of "pre-quilt" you're referring to. Primaloft doesn't absorb hardly any water and neither does momentum. I think scrim would absorb more water per weight than either of those, but it's so thin. What I'm saying is no matter how many sponges you put over something you want to stay dry, even if those sponges could absorb water, the sponges will eventually seep water out of them and onto the thing you wanted to keep dry. Also, they would get very heavy as they absorbed water… and I just can't see how having a wet sponge right up next to a down jacket could be a good thing.

I'm not sure either why you chose the Patagonia Houdini for this application. That's just a DWR jacket and will wet out.

Instead of using non-waterproof components, why not simply use waterproof rain jackets in the construction of your jacket? Just use two fully finished waterproof/breathable jackets, perhaps a size medium for the inner one and a size XL for the outer one, and glue the baffles in place (sew the hems and the cuffs of the sleeves). As you glue each baffle, stuff it with down and move to the next one.

">I would think that a down jacket with a non-breathable external shell would be a sauna.

wouldnt that be wonderful? a sauna at 0F while others are feeling cold?"

No. It wouldn't. Not unless you plan on not wearing any clothes under the a vapor barrier jacket anyway-and for a down vapor barrier jacket, it should really be waterproof or moisture from sweat accumulation could migrate into the down. The main problem is, since vapor barriers don't allow your sweat to evaporate like it would normally do, all your clothes you have on underneath it get wet. Wet clothes in cold weather is just not a good thing.

I have had no exprience with either using down or construction so my comments are based only on the knowledge I have gathered from this forum rather then exprience.

>Just use two fully finished waterproof/breathable jackets, perhaps a size medium for the inner one and a size XL for the outer one, and glue the baffles in place.

The problem is that vapour will still pass through and will be absorbed by down. It will ok if Aaron is planning to use a warm tent. If Aaron is planning to use a tarp and/or a bivy then there are chances that the dew point is inside the down garment then vapour will freeze inside. VB is neccesary then. It is better to use WP fabric (not WPB).

As for for the construction just gluing the outer and inner shell is not a good. It will create cold spots. You need to have baffle walls. Aaron is really good at it.

>Not unless you plan on not wearing any clothes under the a vapor barrier jacket
Well I plan to wear a wool base layer. As you know wet wool is not a bad thing.