0.8 oz vs 1.1 oz ripstop nylon for quilt?

David,
I got 2 yards of the 0.9 oz taffeta (from thru-hiker) a few days ago. If the material was cut right on the 2 yard line and at 60″ wide it weighted out at 1.15oz a sq yard. When I cut it to make something with it I will weigh another piece and re-check the weight.

Sounds goooood. Thanks Bill.

If we assume the weights are what they are supposed to be, and you used 4 full yards of 60″ wide fabric (for both the top and bottom quilt layers), the difference in weight between 1.1 oz and 0.8 oz would be just about 2 oz. I would guess your quilt bag will taper towards the foot, the the difference in weight between the two fabrics might be a little less.

Jay
MYOG

Lighter fabrics such as 0.8 and 0.9 are suitable for polyester quilts and the highest quality down – 800 cu.in. and up. Lower loft down contains quills that poke through the lighter fabrics and can cause considerable damage.

Light fabric is less wind resistant and less water resistant. You might consider using 1.1 dwr for the outside and either of the lighter fabrics for the inside.

Lighter fabtic on the inside will often feel better and give a better drape if you are using a space-filler cut. The exception is the excellent teflon DWR 1.1 from Thruhiker. It seems never to feel clammy.

Note: Any 0.8 ripstop you find will be residual stock. The mill has stopped making it. The 0.9 taffeta is new production. Performance will be about the same.

Thanks for doing the calculations Jay. Thats pretty much what I was looking for, and more or less what I expected – 2 total oz in weight savings really isnt all that significant, but perhaps it would be worthwhile option to consider. Maybe I’ll use Vick’s reccomendation, and use the .9 oz taffeta on the inside, and the 1.1 oz DWR ripstop on the outside. I wonder why the .8 oz ripstop nylon was discontinued, especially if the heavier taffeta is going to perform identically? (indeed, if Bill’s measurements and scale are accurate, its really much heavier, unless the .8 oz nylon was always underestimated as well)

Thanks guys,

Dave:)

Yeah, Dave,
fabric weights are usually only approximate. They don’t include any treatment put on after weaving. And the weight before treatment is only approximate. Mills usually give the weight based on the denier of the yarns, not on actual measurement. They get their yarn from somewhere else, and if it is close enough to their specifications to work in their looms without significant adjustment, they call it good. They may have ordered 30 denier and received 32 or 33 or 28. [The denier is the weight in grams of 9,000 meters of yarn. Small variations are hard to measure and are irrelevant to the mill.] The fabric ‘weight’ they give is based on a measurement taken way back when, and now they are mostly guessing based on past experience. Really. Bummer, huh.

The 0.9 taffeta will not perform identically to the 0.8 ripstop. It should be more down resistant and wind resistant.

The particular DWR I like for the outside of a bag is the Teflon-coated 1.1. Teflon DWR is much more durable than other “durable” water repellent treatments and it seems to work better at any point in the life cycle. It may be a little heavier, but I have not measured it.

A bummer indeed, but thanks for the info Vick. This is going to be my 3 season quilt, and perhaps I’ll do a bit of experimenting with other fabrics for a lighter, less critical summer bag. It might be wise just to work with what I’ve got the first time through anyway.

-Dave:)

Hi all,

I wanted to offer a few observations and some solid info on DWR light fabrics and weights. It is extremely rare than a fabrics ID number, .8, 1.1, etc, is what it really weighs. The industry standard is to name it for the uncoated or untreated weight. So, the familiar 1.1 silnylon is closer to 1.35 and a .85 DWR nylon is about .95-1.0.

Another factor in light fabrics (light nylons, silk , etc) for sleeping bags or clothes is that a lighter fabric can always be used but it may pass air too quickly and then you have to use more insulation for the same temp rating.

For a while I used a .8 DWR (really .9) in the pursuit of lighter and lighter and since I’ve switched exclusively to the Momentum 90 DWR from thru-hiker.com(about 1.05) I’ve seen a big difference in the warmth, fabric strength and DWR quality.

So, the small weight gain in the fabric results in a net gain for the temp rating, DWR effectiveness and the amount of insulation needed (possibly less).

FYI on the Momentum 90, the outside is flat black for speedy drying and the insisde is heat calendared for downproofness. It’s awesome stuff for bags, clothes and bivies. A bivy from it may weight .5oz or more than a .8 (.9) fabric (ex. Pertex Quantum at 30gm/sq/m or about .9) bivy, but it’s a good trade-off in DWR protection and strength.

Along the same lines, a 1.1 or a 1.3 DWR may not have as good a DWR as a lighter fabric.
-Ron

Thanks Ron. So, I guess your suggestion would be to drop the 1.1 oz nylon that was sent with the Ray-Way kit, and pick up some of the Momentum 90 from thru-hiker. Hmmm…what to do, what to do.

-Dave

I have a related question

I have an old bivy sack from Stephenson Warmlite which is made from totally coated ripstop and therefore doesn’t breath. The thing comes in two zippered sections. I was thinking of transferring the zippers from the top section to lighter more breathable material. Ron you stated the momentum would be good for a bivy; Would you suggest the momentum for a balance of good breathability and a little spray, splash, moisture resistance? I’ve been looking at Ayce’s materials list for about a month now and scratching the noggin. Thanks in advance for any advice.

What is the difference between Momentum 90 MR and Momentum 90 T. What should i choose for 850+ down UQ. Thank you!
-Lesha

MR = Mini Ripstop

T = Taffeta

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The MR should be a bit more tear resistant

Thank you! I'll go with MR. Don't think I would feel softness of taffeta UQ through a hammock…