How to make a DIY Insultex (IX) underquilt for hammock camping: MYOG

Compared to many underquilt options, this DIY Insultex UQ / IX UQ is fairly simple, easy to construct, and inexpensive.
How to make a DIY Insultex (IX) underquilt for hammock camping: MYOG

original BWDD IX UQ plan

To provide some insulation for the bottom of a camping hammock, many folks use an insulating blanket wrapped around the outside of the hammock body. Since common practice is to use down for insulation, a quilted construction method is used. So, we have a quilt that hangs underneath a hammock, hence the name “underquilt” (UQ for short). I made a summer weight UQ out of a single layer of fleece approximately 90″ x 55″, with a darted, offset cut to help the quilt conform to the shape of the bottom of the hammock. The fleece UQ is not warm enough to use alone in the winter or even shoulder seasons. So, I set out to find a way to make my own insulating quilt without spending the $200-$300 that is common for a professionally made down UQ. I started with this plan from BackWoodsDayDreamer (image to left, full directions at the bottom of this page below the photo gallery)

I really wasn’t ready for this project, as I was still kicking around a few design ideas and hadn’t even really decided to go with this type of rectangular 3/4 length style.
However, I couldn’t sleep one night and decided to try the BWDD plans and see how it turns out. Compared to many UQ options, this DIY Insultex UQ / IX UQ is fairly simple, easy to construct, and inexpensive. I may not suggest this as a first project, but it is definitely a good intermediate project for MYOG / DIY types, campers, hikers, Scouts, etc. The construction methods used here could also be used to make insultex top insultation, top quilts (TQ) for ground or hammock sleeping, or emergency blankets for survival use.

Being 6’4″ I wanted to do something longer than 60″, but with only a touch over 4 yards of IX (acquired by trading a hammock peak bag that I made) I figured this was probably about the most efficient use of the IX. After cutting the panels to size, I have about 12″ x 60″ of IX to play with, or maybe use as draft tubes. I also have the thin packing foam from a big TV that I may try to use similar to how IX is used here.
I have read that additional panels of IX can be added to this kind of setup, giving it additional flexibility in the temperature range.

How to make a DIY Insultex (IX) underquilt for hammock camping: MYOG

How I did pleats instead of darts in the ends

What I did different from the BWDD plans:
-I made 1 inch pleats instead of darts.
48″ layer has 6 x 1″ pleats at each end. I did not space them evenly. I was thinking that since my shoulders are sort of flat, I’d leave the very middle section flat, and added the pleats out towards the edges a bit.

46″ layer has 4 x 1″ pleats at each end.

44″ layer has 2 x 1″ pleats at each end.

I used a 65″ x 65″ piece of 1.1 oz RipStop nylon for the bottom cover.
Since the RipStop is taller and well wider than the 60″ x 48″ IX panels ( 48″ at their widest point), I was able to fold the RipStop edges over to make a channel for the suspension bungees.
This also allowed for a wider flap/channel/draft tube on the long sides to act as a seal against the hammock. I may put some rolled up IX in them , or may try something else to give them some volume to help them seal against the hammock and block the cold. For the first test they worked well with nothing but the suspension shockcord running through them.

How to make a DIY Insultex camping hammock underquilt: MYOG

Jeff's adjustable hammock underquilt suspension

My hammock underquilt suspension is a bit different than many that I’ve seen. I run shock cord the full length of each of the 4 channels, with barrel toggles in the center of each shock cord for adjustment, and an extra 18″ or so on each end of the long channels to connect to my suspension triangles (making the shock cord on each long side about 96″ long).

I  used very limited grosgrain as reinforcement on the ends where the suspension shockcords exit the channels, instead of running full grosgrain channels for the suspension.
The current plan is to leave the top side of the UQ uncovered, as it will be up against the hammock, and not exposed to the elements.

I thought sil was hard to work with, but found IX to be far more challenging to keep lined up properly. The darned scrim wants to slide all over the place! I HATE to pin, but ended up doing lots of pinning (well, lots for me) and still have some of the worst looking seams I’ve ever sewn.

Looking forward to getting a final weight and temperature rating. Hoping for less than 1 pound.

Update April 14, 2011:

Final weight turned out to be 16.03 oz, so right at 1 LB, as I had suspected.

The UQ, suspension, and suspension triangles roll up in a small stuff sack.

How to make a DIY Insultex (IX) camping hammock underquilt: MYOG

finished UQ rolled and in the stuff sack beside a 1L Nalgene bottle

How to make a DIY Insultex (IX) camping hammock underquilt: MYOG

Stuffed IX UQ

January 31, 2011 update. First trip report:

My first test of the 3 layer IX UQ was a success.

Low temp: 24* F, wind was light and variable
Was 36*F when I entered the hammock. Everything warmed quickly and I shed my fleece pull-over and wool socks so I wouldn’t sweat.
Woke up a few times overnight and checked temp. Bottomed at 24* and was that temp for about 8 hours.
Above freezing my back was about the perfect temp. Below freezing my back was a touch cool. Not cold, not even chilly… just a bit below perfect. I was never cold and always able to fall back asleep very quickly.
Next test will be with the UQs switched. ie. IX on the inside, fleece on the outside.

Other gear:
My DIY Frankenbird hammock
DIY triangle suspension adjuster “thingies
DIY Ogee tarp pitched low over hammock, but not too close to the ground

1988 vintage kelty ridgeway 15* mummy bag on top as a TQ
single layer fleece TQ
small fleece blanket as a pillow

closest to hammock: Fleece DIY UQ (single layer fleece with nylon shell on both sides. KAQ dimensions and cut)
outside layer: 3 layer IX UQ with pleats instead of darts and 1.1oz RS shell on bottom only

knit cap
long sleeve single layer UnderArmor type shirt
“performance fleece” long pants
no gloves
I removed my fleece pullover and wool socks pretty quickly as I was too warm.

Here is the video I shot during the test hang. :)

Pictures of the work in-progress, and the finished UQ in use:

The following are the original BWDD directions, as posted at by sclittlefield:

4yds Insultex
3yds Shell material (unnecessary, but I prefer 1.1oz ripstop to add durability)
20ft 1.5″ Gross Grain (channels)
24ft 1/8″ shock cord (suspension)
3 cordlocks (suspension adjustment)

1. Cut out the (3) raw sized panels of Insultex, as seen in the drawing.

2. Mark your V-cut-outs (aka-pleats). A sharpie works well.

3. For each V-pleat, fold in half the long way, and sew your lines together (you can cut the flap out or leave it, doesn’t matter much either way). When you’re done, all three layer pieces will have equal lengths and widths – 42″ wide and 60″ long – by these specs offered.

4. Shell Material Sub-Directions: Shell material is useful for adding durability to the Insultex, but it also adds weight. One good option is to add shell material only to the outside, as the inside will be against your hammock and be protected.
–4.a. Cut and sew to the same pattern as the corresponding IX layer.
–4.b. Fold V-pleat over after sewing and sew flat to fabric (similar look to a flat felled seam).
–4.c. When sandwiching layers together, be sure the proper side of your shell piece will be facing out.

5. Sandwich all layers together in order. Use lots of pins here, as the differentially sized layers will fight each other.

–Bottom Shell–
–Bottom IX–
–Middle IX–
–Top IX–
–Top Shell–

6. Sew the perimeter of your quilt, approx. 1/2-5/8″ in from the edge. If you sew too close, you may find you don’t get through all layers as some shifting may occur. If you’ve sewn too far from the edge so that the gross grain will not cover your thread, feel free to trim to approx. 1/2″ from your sew line.

7. Cut (4)1.5″ Gross Grain lengths to the height (2 pieces) and width (2 pieces), plus 2 inches. For example, the width is 42″, so cut (2) 44″ long pieces of gross grain. For a finished edge, fold the ends in, or heat seal with a candle or lighter.

8. Fold Gross Grain in half (long ways, so the 1.5″ gg is now 3/4″ wide), pin pieces to corresponding perimeter edges of your quilt, and sew in place, being sure you are sewing through all layers. Sew two parallel lines for added durability.

9. Use 36″ of shock cord running through each of the short edges of your quilt channels. Sew one end of shock cord to the end of your channel, and use a cord lock at the other end for adjustment (Be sure to use a good knot on the end of the shock cord so it doesn’t slip out of the cord lock). Alternately, you could put a cord lock on either end if you don’t want to sew the shock cord in place. This will require two extra cord locks.

10. Run the remainder of your shock cord through one long channel, and back through the other long channel. Slip the two loose ends through your last cordlock and tie a knot. (Heat seal your shock cord with a candle or lighter to keep the sheath from fraying.)

11. Place the shock cord over the end knots of your hammock and use the cord lock to adjust. The under quilt will be able to slide back and forth along the channels for easy positioning.

Notes: Insultex does not stuff well, but it does roll well. Fold and roll your quilt, rather than attempt to stuff it into a sack. This will save a lot of space.

Currently, IX can be purchased hereTreeToTree Trail Gear