I have more than a dozen sleeping bags and I was thinking about making an underquilt out of one. Well my wife will, she is a good sewer.
I am a shoulder season camper and I will have an air mattress as well. Any thoughts, tips or tricks?

AmarilloJim: "I have more than a dozen sleeping bags and I was thinking about making an underquilt out of one. Well my wife will, she is a good sewer.
I am a shoulder season camper and I will have an air mattress as well. Any thoughts, tips or tricks?"

Just buy one.

Nah, she will like the challenge.

While the challenge is noble and the task do-able I am not sure the outcome will be worth the effort. Two big advantages of the UQ are the weight and ability to compress. My warbonnet with top and underquilt compress into a bag smaller and lighter than my sleeping bag alone.

Just google DIY under quilt there is about 50 vids on how to make under /over quilts. Many do the "Costco" and cost about 30 bucks for a great quilt for shoulder seasons building 2 my self now total cost 50 bucks and my time. There are also vids on using a bag to make one

An air mattress in a hammock will be like a slip-n-slide.

lots of idea's on u tube, just research it and go for it. if you have the down bag, it should be a fun diy project. see hammockforums.org.

oh, once you have the uq, forget the pad, it will be more comfy without it. i am 6'tall and ordered a down uq that is 58 inches long. keeps me plenty warm in 3 seasons. it is a long 3/4 length. i think it is around 42-45 inches wide. run a shock cord down both sides, then a shock cord on each end to sinch it up and you are done.
use cord locks to sinch em up. i have made one, easy and slick. i used an old down blanket. let me know if you have any more questions.

Here is my build thread. I have since made two of this design and love em' !
The best gear is homemade gear.

it was nothing fancy, not water proof material either, but i did use it out back for a few overnights in the back gardens.

No discredit to your wife, I'm sure she's capable but I think you'll be fighting with this project so long. Do you really want to go there? Sewing a DIY tundra tarp is one thing. But this involves insulation, thermodynamics, worse yet getting it to fit right not only on your hammock but with your weight sitting in it too. Idk about you but insulation is actually really expensive (I wouldn't think of using a down less than 850 fill), and it's going to take a lot of figiting, cutting baffles, buying more insulation, putting more in this vs that baffle, dealing with and predicting how the down will sit, and overstuffing precisely thought out baffle dimensions to get a decent temp rating. If you're thinking of taking that old insulation good on ya, but the fight of accomplishing a good temp rating will be thatmuch more of an uphill battle than buying new material. Good luck to you and your wife.

hey jim, how's your diy project going, like to see your wife's sewing skill's!

bwcasolo: "hey jim, how's your diy project going, like to see your wife's sewing skill's!"

Haven't asked her yet. Still waiting for the right moment LOL. I have a double layered Blackbird so the air mattress should do nicely. Just thinking a little extra warmth with a DIY underquilt is all I need.

I have used a backpacking air pad in a double layer WBBB while my brother used the UQ in my old Byer. Pad worked well down to low 30s. A pad in the Byer was more of a challenge when I tried it once.

I also made an UQ from two 45d down bags that zip together ( wide enough) and some shock cord. Took some tinkering but worked well enough with no sewing. Just tied onto the bag loop points.