Insultex Quilts - Top and Bottom

[TeeDee]

Insultex Quilts

I have posted about my Down Karo Step top quilt design and my Bridge Down Under quilt design previously.

I have completed the design, construction and testing of my Insultex quilts, both the top quilt and a Bridge Under quilt.

All of my Insultex quilts use 3 layers of the Insultex material.

I learned last year in experimenting with my Insultex hammock which was a Bridge hammock with the Insultex sewn directly to the bottom of the hammock, that it was necessary to have an air gap between me and the Insultex. I knew this already from what I had read of the i.d.i.gear Arctic Armour outfits. The people using those outfits advised getting a size at least 2x bigger than a person normally wore so that the garment was not pulled tight against the wearer at the shoulder, knees, elbows or butt. If the garment was pulled tight, a cold spot developed.

I'll describe my top quilt first. In order to keep the Insultex from being pulled tight against the user, I designed a differential cut top quilt:



From the illustration you can see that in order to keep the Insultex from being pulled tight against the user, I have made the inner shell 50" wide and the Insultex layers and outer shell all 60" wide.

I have also incorporated 6" draft stoppers on each side and draw cords at both the foot and head ends. Since I made the top quilt 50" wide, the draft stoppers are not really needed in a hammock and are there primarily for a go to ground capability. Since the Insultex material is 60" wide, making the top quilt as wide as possible and utilizing the full 60" width didn't cost any more. A definite advantage over down where any added width or length cost in down filler.

I decided on an 80" length since that gives plenty of top quilt to cover the feet and the head. With an 80" length, it should be possible for even someone 6' 4" or 5" and possibly more to wrap their head with the quilt.

The final dimensions of the quilt are 80" L x 50" W. In the JRB stuff sack it weighs 27.80 oz. This compares favorably with my Down Karo step top quilt at 27.30 oz in the same JRB stuff sack.

Here's the top quilt with the foot box formed. If you look closely you can see the draft stopper on the near side and the extra material for the Insultex and outer shell:


Here's the view with the foot box opened and the inner shell of the quilt. You can see the draft stoppers on both sides here:


For the under quilt, I again used a differential cut to maintain the air gap between the user and the Insultex. My Bridges are all cut with a 44" end width and a 6" arc depth. For an under quilt, the top shell is an exact duplicate of the Bridge Hammock using 1.75 mm guy line cord on the arcs. The Insultex layers and the outer shell are all cut with a 60" end width and a 9" arc depth. The added arc depth is necessary to keep the Insultex and outer shell layers from pulling up and above the Bridge Hammock arcs when the Bridge Hammock is occupied. This would eliminate the needed air gap.

The under quilt is attached to the Bridge Hammock quite simply and easily by using the arc guy line cords by tying with a toggled half hitch on suspension triangle cords at the Bridge Hammock corners. I have found that this design for a Bridge under quilt necessitates that the top shell fabric be an exact duplicate of the Bridge Hammock it is used on and that the corners of the under quilt must line up exactly with the corners of the Bridge Hammock. By using the same pattern for the top shell fabric as was used for the Bridge, doing this is very simple and easy.

Here is the Insultex under quilt laid out. First showing the outer shell:


Then the inner shell:


In the JRB stuff sack the under quilt weighs: 22.95 oz. This compares favorably with my down bridge under quilt at 22.95 oz in the same JRB stuff sack. Surprisingly the weight of the Insultex under quilts came out exactly the same as the down under quilts. - this was not planned.

I have used the top quilt and the under quilt together this winter and find them to be toasty warm and extremely comfortable. With the differential cut of the top quilt, the top quilt feels as good against the skin as the down top quilts. The coldest I got this winter was 11° F and I was toasty warm wearing only cotton briefs, cotton Tee and cotton socks. My down top and under quilts all have between 5" and 5.5" of loft and according to one web site I found in the past, I believe that that should be theoretically good to about -20° F. I have no way of knowing just how cold the 3 layers of Insultex can go. The only thing I have there to go on is the experience of ice fishermen who report that they are comfortable sitting around in their Arctic Armour gear down to single digits F wearing the same thing I wore.

Shown here are the Insultex top and under quilts in the JRB compression sacks alongside my down Karo step top quilt and down Bridge under quilt. I have included a 32 oz Nalgene bottle for size comparison:


The Insultex quilts are on the top with the down on the bottom. The under quilts are on the left and the top quilts on the right. All of the compression sacks are 7" diameter. All are 9" high compressed except the down under quilt on the bottom left which is 8" high. All were compressed as much as possible by stuffing, rolling the top twice, kneeling on the sack and cinching the strap down as tight as possible.

The Insultex top and under quilts have now become my preferred and go to quilts. This due to several reasons:

1. comfort - the Insultex top quilt is as comfortable as my down top quilts
2. temperature - I know that I can get to 11° F with minimal clothing and feel another 2° F to the single digits would be easily possible with the same clothing. I feel that by adding my merino long johns which I reserve for night wear, I could be comfortable even lower.
3. weight - the Insultex quilts are equal to or only 0.5 oz heavier than my down quilts.
4. coverage - the Insultex quilts are full coverage. Since the cost for full coverage was exactly the same as for limited coverage, I opted to make the Insultex quilts as big as possible. This was not possible with my down quilts since the cost of down became prohibitive, even with Ed's generous HF discount.
5. bulk - even making the Insultex quilts as big as possible, they are the equal of the down quilts compressed in the JRB compression sacks.
6. compression - I can store my Insultex quilts compressed in the JRB compression sacks as shown. This makes them always immediately available when I go into the field. This definitelty cannot be done with my down quilts. This isn't something that would keep me from using down, but for convenience, this is great for me. This could be something that would definitely keep somebody from using down and instead using the Insultex if they were considering a BOB. For the BOB, the extremely high priority of grab and go precludes down. The Insultex quilts would be ideal for a BOB.
7. the Insultex is impervious to water. This is a big advantage over down. I haven't tested yet, but I'm pretty sure the Insultex quilts will be field dry-able, which down is not. This also makes the consideration of rain blown under a tarp much less of a concern than for down.
8. I can use uncoated fabrics throughout. Down proof fabrics are needed for down, which are usually DWR coated fabrics. The DWR coating makes the fabric heavier. The uncoated fabrics are better for passing any condensation through and not trapping it.

Summary:

I will be switching to my Insultex quilts for all of us in the future. Just too many benefits not to do so.

The compressed bulk and weight is equivalent to my down quilt design.

Weights in JRB compression sacks:

Down top: 27.30 oz
Insultex top: 27.80 oz

Down under: 22.95 oz
Insultex under: 22.95 oz

[Dutch]

Are you sure the down and the insultex quilts will have the same rating. They look great by the way.

[TeeDee]

Are you sure the down and the insultex quilts will have the same rating. They look great by the way.

Do you mean temperature rating??

I have no rating information for the Insultex quilts. My personal experience is toasty warm at 11° F and confident I can go lower, but have no means of knowing just how low.

The loft on the down quilts is 5" to 5.5" and I believe there is information on the temperature rating for down somewhere on the web - I found it in the past. If my memory is correct, that loft should be good to -20° F.

[T-BACK]

How is the cost comparison. If you have found a way to compete with down, my hat is off to you Brother!

[TeeDee]

How is the cost comparison. If you have found a way to compete with down, my hat is off to you Brother!

Cost is considerably less.

The Insultex on the group buy was under $3.00/running yard. But that was the group buy.

Figure the cost if Insultex becomes available by the yard at $6.00/yard. The shell fabrics for the top or under quilt is the same cost for either down or Insultex.

I used 4 bags of Ed's down for my under quilt. At his HF discount that came to $96 for the down. 7 yards of Insultex @ $6/yard is $42. Cost savings for each under quilt is $54. For the group buy, the cost savings was much more impressive. I forget the exact $/yard on the group buy, but assume $3/yard, so the savings for us is actually $75+ for each of our under quilts.

For the top quilt, again I used 7 yards of Insultex. Again $42 for the Insultex. For my Karo step down top quilt design I used 5 bags of Ed's down. At the discount price that came to $120. The cost savings for the top quilt: $78. Again for us under the group buy, the savings are actually $99+ per top quilt.

Didn't somebody else buy rolls from i.d.i.gear and make it available on the forums. Don't remember what the price there was, but I think TiredFeet said about $4 or $5/yard. So the cost savings would be even better than the $6/yard I figured above.

Now if you figure the cost of the down at Ed's regular price, the cost savings is even better. Even figuring the cost using 800 fp down, the unit price for the down is lower, but to get the loft that I got with Ed's 900 fp, you are going to use a lot more, so the cost savings may be about the same. It pays to use Ed's 900 fp if possible.

You also have to consider that the Insultex material is 60" wide and any use up to that width is going to cost exactly the same, i.e., a quilt 46" wide is going to cost exactly the same as a quilt 60" wide. For down you pay more for added width or length. My Insultex quilts are bigger than my down quilts for this reason.

My down under quilt design doesn't cover the whole underside of the Bridge hammock, but covers only the portion occupied. My Insultex under quilt covers the whole Bridge Hammock. I could duplicate the limited coverage of the down under quilt, but why bother. To do so would not save any money, the time consumed in design and construction would be much greater than the whole coverage and the weight savings would only amount to about 1 oz or less. I very quickly decided it wasn't worth any weight savings to limit the coverage. The limited coverage $ savings for down were very considerable.

My Karo step top quilts are 42.55"x36"x72" to make the best use of the down. It is not usable for a go to ground use unless you are a back sleeper. My Insultex top quilt is huge at 50"x80", easily usable even by a side sleeper on the ground and at a considerably lower cost.

[TeeDee]

TiredFeet just reminded me of another advantage we discovered of the Insultex quilts over the down quilts:

The Insultex quilts are much, much, much, much easier to stuff into the stuff sacks and once stuffed they are much easier to compress.

The Down quilts balloon up and out when you are trying to stuff. That makes the stuffing harder. Also, when stuffed the down is trying to reloft and ballooning and make it hassle to get the top rolled and the cinch strap ready to cinch down.

The Insultex fabric is uncoated so the ballooning effect is much reduced and the Insultex isn't trying to reloft like the down is. Once stuffed, rolling the top is easy and getting the strap ready to cinch is very easy.

All in all, we can stuff and compress the Insultex quilts in about 1/3 the time or less of the down quilts. And a lot less swearing.

[Trugracie]

How many inches did you add per layer?
Ex 50" inner shell
52" 1st
55" 2nd
58" 3rd
60" outer shell

[T-BACK]

Thanks Tee Dee,

I was just doing some reading up on it in some of the earlier posts. Looks like I've missed a lot. I would like to get some of this stuff. You addressed one of the major problems I have with top quilts, they don't cover me on the ground. I will be waiting impatiently for your testing results. You guys may have stumbled onto one of the Holy Grails of hammocking

[sclittlefield]

Taking that comfortably to 11 deg. is very impressive.

Makes me wonder what the climashield TQ w/2layer IX overcover will really do for me... maybe better than I expect. Thanks for posting (and pics!). I look forward to more info as it comes about.

[Knotty]

Great info here TeeDee. I had sort of written Insultex off until seeing your results.

Have you taken into consideration that IX doesn't really breathe? Won't there be condensation issues sleeping in a vapor barrier top and bottom?