Insultex/Cuben Underquilt for Bridge Hammock

[Tenaya]

Hi folks,
Now that I can operate a thread injector well enough to get by, I've decided to tackle an underquilt. I have an IX underquilt for my Hennesy from Molly Mac gear that I really like, but it wasn't a great fit for my new bridge hammock. So, I made my own. I used 2 layers of Insultex, with a layer of .34 oz Cuben on the outside to keep things clean, and hopefully it will have some additional barrier effect as well. I slept pretty warm with the Molly Mac UQ, which I think uses 3 layers, but I think I should be fine with 2 plus the Cuben, especially for a summer quilt.. I have enough leftover IX to make an additional layer if needed...I'll just cut to shape, bias tape the edges and slip between the hammock and quilt if needed.

First step was to cut a pattern the shape of the main hammock body. I then marked out the pattern on one layer of IX. I then stacked this on top of a layer of Cuben and another layer of IX, with the Cuben in the middle between the two layers, rough cut leaving a couple of inches margin, and pinned. The Cuben goes in the middle, but when the quilt is mostly stitched and turned inside out will end up on the outside.


Next, I made four shock cord ties, one for each corner. I took some shock cord, made a loop, and sewed some polyester twill tape on the ends, to make a tab so that I could bar tack that into place and have a nice secure attachment point.


I then put the loops in between the two layers that I wanted to end up on the outside...in this case, the unmarked IX layer and the Cuben, making double sure all loops were on the same layer. I put them in with the loop pointing in, with the tab outside the stitch line. That way, when I did the main stitch line, it stitched over the cords. When the stitching was done, I then went back and bar tacked the tabs to the extra fabric.


So, I stitched around, leaving a 2ft opening at the head end. After bar tacking the cord tabs, I cut off the excess close to the stitch line, cutting around the cord tabs. Then, I turned it inside out tucked in the remaining open slit, and through-stitched to close.

Here's the results:

Cuben face up (the outer/lower face):


IX side up (right side up):


On the hammock:


Basically, I just loop the cord around the ends of the spreader bars, with an overhand knot to reduce the loop length if needed. I had thought about using some sort of mid-point attachment, but this fits so well I don't think it will be needed.

Final weight, with stuff sack, is 7.5 oz.

Hope to field test in a couple of weeks!

[MacEntyre]

Very nicely done! I made an UQ for a bridge once...

The first IX UQs I made were had no cover. I thought that was the best approach for SUL, being both cost effective and complete. But, folks wanted a cover. Adding a cuben cover crossed my mind, but seemed to be adding a relatively large expense, without much value.

If I were to make one, it would be a Baby Orca, with a cuben cover on the outside only.

[Tenaya]

Very nicely done! I made an UQ for a bridge once...

The first IX UQs I made were had no cover. I thought that was the best approach for SUL, being both cost effective and complete. But, folks wanted a cover. Adding a cuben cover crossed my mind, but seemed to be adding a relatively large expense, without much value.

If I were to make one, it would be a Baby Orca, with a cuben cover on the outside only.

Thanks! And I agree, you really only need the cover on one side, in case it falls in the mud or whatnot, and Cuben does cost a fair bit, so keeping it to one side is a cost savings for sure.

[Otter1]

Great tutorial and pics! Finely made gear. Please report back.

[GrizzlyAdams]

nice trick with embedding the cuben inside, and then turning it inside-out to get the raw edges of the seam inside. I'll remember that one.

My experience with insultex has been that you cannot compress it or you have a cold spot. It does great trapping air. As the UQ is already built, I think the challenge for you will be to set the tightness when you hang it so that you don't compress it at the butt, and hope that the rest will (a) leave only a small gap between hammock and UQ, and (b) get some seal at the ends. Someone else, TeeDee probably, did an UQ with it and I think the strategy used there was to use a slight differential cut to create an air gap between the first and second layers of the Insultex, something like that.

My next project will be an UQ also, 0.3 oz cuben shell on both sides with some ripstop for air to get in and out, differential cut, minimal sewing. A fine fine job for the middle of a hot August!

[Tenaya]

I think the strategy used there was to use a slight differential cut to create an air gap between the first and second layers of the Insultex, something like that.

The key for me is to be not very good at getting the layers to stay perfectly put while sewing, so I kind of got an unintentional differential cut. I made the cords longer than I thought was needed so I would have some leeway. That and with the stretch of the shock cord also, I'm thinking I can keep it just slack enough to avoid CBS. Fingers crossed.

[Redoleary]

Well done, that looks great on your bridge.... like it was made for it.

[Tenaya]

Date: Aug 13
TQ: Stormcrow's 50°F Burrow (Hammockgear.com)
Location: Kilkenny Loop, Pilot Range, White Mountains, New Hampshire
Campsite: "Unkown Pond" campsite, elevation 3200ft
Temps at nearest weather station at elevation 1620ft:

8/13 22:00 61.8 °F

8/14 00:00 60.1 °F

8/14 04:30 55.1 °F

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Report: UQ worked fine. Perceived warmth was adequate without overheating or condensation. There was no perceivable tightness in the UQ. There were substantial gaps or sagging in the midsection, which seemed to be largely corrected by pulling the corners tighter.

I'd say for me, two layers IX + lightest weight cuben was just fine for summer nights in the Appalachians. Of course, the standard caveat applies: YMMV.

Lessons learned: If redoing this project I would make the corner suspension loops much smaller, and add one or two loops to each UQ long edge at midspan, along with corresponding buttons sewn along the hammock edge, to pull the side edges tighter to the hammock along the long edge. Even better would have been to add separable zippers running down each side of the hammock & UQ, then there would be no gaps at all.

I think for my next hammock, I might even consider making it a double layer, with 2 layers of IX and an outer shell layer sewn on 3 sides, and a zipper down one long side, so I could insert additional layers of IX for more insulation on colder nights. Seems like it might be a pain to try to shove an IX pad down the length of the hammock via an end opening, but would like to hear feedback on other people's double-layer experience and what they think about that, since it would save the zipper weight.

Future tests: I have a trip to Yosemite planned for 9/20. I plan to add at least one layer of IX between UQ and hammock, will see how that works out. Stay tuned!

[Otter1]

Thanks for the update! Can't wait to hear about your Yosemite trip.

[Jazilla]

Now you know a video is a must. It looks like you cut the demensions of the UQ exactly the same as your Bridge, is that the case? It looks like you did a really great job.