Underquilt Concept, good or bad idea? Your thoughts?

**TenInchRichard** · 07-06-2021, 21:34

Greetings all,

I am building an underquilt using a modified blueprint from this forum. Maybe someone here has already tried this configuration and failed, I would like to throw this idea out to an experienced community before committing any sweet sweet 1000fp down
.

The idea is to make the underquilt out of a combination of .56 oz MEMBRANE 7 Ripstop Nylon, .34 oz dyneema composite(when I can find three yards of it), shock cord of various widths and 1000fp treated down.

Dyneema on the bottom side offers the benefits of an ultralight underquilt protector. Having the top side be nylon allows for the quilt to breathe. The baffles would all be made of .34 dyneema as well.

I assembled a dynamic BOM in excel for different baffle heights and other dimensions and determined I want to start with a 2in baffle(for roughly 30 degrees), this should weigh a hair over 14 oz when complete. If this works then I want to make a 4in sub-zero model down the road that weighs about 22.5oz to help combat this 9 month long MN winter we get around here.

Your thoughts... Show snow mercy, I want to make sure this investment is well thought out and I want to continue my research by having this idea ripped apart by people who eat, breathe and .. breathe this kind of project.

Best regards and thanks you all,

Dave Welter

**GilligansWorld** · 07-06-2021, 21:54

I think it's a solid concept - Dyneema is awfully loud however.

Not sure how down proof dyneema is. Have you thought of reaching out to anyone like Kyle from rip stop by the roll or perhaps Dutch from dutchware?

Certainly would be an inquiry I would make before I attempted this project.

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**SilvrSurfr** · 07-06-2021, 22:28

I highly doubt that quilt will breathe. You seem to be making the assumption that a quilt only breathes from the top, but I don't think that's the case. Nobody sells a UQP made of waterproof material.

To put it another way, if one side of your underquilt is waterproof and non-breathable, then your underquilt is 50% less breathable than one made with DWR nylon.

**leiavoia** · 07-07-2021, 02:13

Yes if half of the fabric is water resistant then it will just trap an alarming amount of moisture and soggy the down on the inside.

Also if you are sewing this from scratch don’t limit yourself to “shock cord of various widths”. Consider a Wookie type or any of the other designs that fit better and have reduced fiddliness.

**cmoulder** · 07-07-2021, 05:09

Ditto on DCF... not the material for the job. Another downside of DCF for this application is that it isn't very stuffable and will take up more pack volume.

Consider Argon67 which is pretty darn wind and splash resistant, yet breathable. A 30deg HG Phoenix made thusly (custom, w/950fp) weighs about 12.6oz. Yes, that's a 3/4 length (depending upon your height) but it is going to be very hard to construct a full-length (say 72") down to 14oz no matter what currently-available materials you use, even Argon49 (7D) and 1000fp.

WV · 07-07-2021, 05:37

I agree with those guys. It won't breathe. The dyneema would be fine for the baffles, but I don't think you'd save much weight by using it instead of mesh. I made an insulated dyneema hammock once, and the insulation worked well, but I had condensation in the hammock. There was an 8" wide stripe of nylon fabric across the bottom layer to let it breathe - not to handle moisture, but to let air in so the down would loft. That worked well, so you could try that, but I don't suggest it. Mine didn't have any moisture to deal with.