Space Blanket UQ
I got brave enough with the materials to try using a space blanket and polyester fill sandwich hung as a conventional UQ. I have posted a couple times on using it inside an under cover.
* I took an AMK double HeatSheet space blanket, folded it over to make an envelope and stuck the sides together with double-stick tape.
* I put a 45"x60" (crib size) batt of Poly-fil brand Extra-Loft polyester insulation in the envelope and sealed the remaining edge with self-stick Velcro dots-- this is a prototype and I wanted access to the inside.
* I tied lines to the corners with a lark's head, capturing a hank of the insulation at the same time.
*The lines run though a closed loop of shock cord.
* I ran the lines so they are on top of the hammock ends. This helps to lift them and keep them and pull the UQ close to the hammock body. The tension can be adjusted by making an overhand loop in the lines, or use a toggle. It could be hung from the whoopie slings with a snap hook hung on Prusik hitches and adjusted that way.
I tested it on a Grand Trunk Ultralight hammock with a modified suspension. The width is perfect and the length is about 60", so at least a 2/3 UQ. It is warm and I think good to 40F or so with a decent sleeping bag and pillow to make up the length. A taller person may like a foam foot pad. I'm 5' 10" and 220lbs.
Weight is 11 ounces and loft is 1/2". Cost was $7 for filler and $5 for the space blanket. I had line, shock cord and tape. You can certainly pull it off for under $20. Assembly time is under an hour, including hanging it. It will stow to a bit bigger than a Nalgene, rolling it up carefully and securing it with a rubber band.
It could be sealed with duct tape, which would reinforce the corners and toughen it a bit. That would add a few ounces and make it harder to roll up. I would leave some "bleed holes" to let air in and out and dry any moisture captured inside. I think duct tape on the corners would help. The filler should be stabilized somehow-- using tape, glue, or stitching through with tape reinforcement patches and maybe buttons.
After doing some testing, it works better to use the shock cord loops in a Prusik around the suspension lines. A higher attachment point helps the shape a bit. The are some problems with sagging at the ends, particularly at the foot end-- my shoulder fill out the top better. Shape can be adjusted by tying to the fabric closer to the center and folding in the excess. Doing that does shorten the effective length. Another way would be to just gather the slack and whip it lightly, or roll it up. You could gather and whip the ends of the sandwich, creating a asymmetric boat shape.
If you really wanted to make a weatherproof setup with these materials, you need two space blankets to get the size. Then you could whip the ends like a hammock and create a complete under cover. The insulation would necessarily need to go the full length; it could be taped to one layer. I wonder which layer would be best.
Could you get it to compress smaller with a small or extra small compression sack?
I'm sure, but it is fragile and compressing it for travel is where it is going to get ripped or torn. A roll top stuff sack would be safer I think. I'm not too unhappy with a "nearly Nalgene" size. This is a quick and dirty solution and has its limits.
If you like the concept, some better fabric can be sewn into a simple envelope and filled with batting. If you really wan to to get into the big time, you could use Primaloft batting and a good windproof nylon with a good DWR coating. It just needs channels or loops in the top edges to hold it up and run for and aft on the hammock sides to locate it to your needs. All of a sudden, you have a "real" under quilt!
You might be able to make duct tape loops or channels on the top edges of the space blanket version. The loops would need to be doubled or otherwise made to keep the glue away from the support lines. You might be able to make a bow-tie shape with the duct tape, basically pinching or folding the center to cover the glue and leaving the fat ends to stick to the space blanket. Four or five of the tape loops across the edge would be good 'nuf. Then you need enough shock cord to run both sides of the hammock. Let me say that once tape is stuck to the smooth surface of the mylar, it is staying put! The tape would last as long as the space blanket and repairs could be made with more duct tape. Why do I get the urge to wear red and green suspenders all of a sudden? :scared:
My first winter UQ I made had 2 layers of poly insulation (Warm 'n White, I believe), and a space blanket. All in a nylon shell. The SB is against the inside of the quilt, and from experience, I rate it about a "20-degree comfortable" quilt. I supplemented it with a few layers of Insultex once, and got down to 9 without freezing. That was pushing it a bit though.
When I made it, I did sew through in a bunch of places to stabilize the batting, and hopefully perforate the SB enough to get some vapor flow (probably insignificant), and have since noticed a few places where I think the SB tore along the stitching.
Really cool experimentation you're doing here, Dale!
"A" for effort but I wonder if dalew is right about strength. let me know how it goes, I need me a uq.
Saw a video on YouTube from"bigT" he made a tarp from the same SB. It seamed to hold up very well in the wind. He left it out for 24 hours in moderate wind. He used packing tape(banding tape??) with the string in it for tie out loops. I am on mobile right now and don't know how to post a link but if you search his handle and space blanket tarp it pops up. His method Might be easier than tying the suspension on the corners. Just a thought.
Hmmmm I like this idea.
Originally Posted by PuckerFactor
Batting is cheap, but it doesn't retain loft well after several "stuffings"... but it's cheap!
If you're using the space-blanket, check out Insul-Brite... It's $6/yd, and pretty warm... but easy to find...
A couple of notes. If you use the space blanket on both sides, the fill has no function as your body heat is being reflected by the inner space blanket, right? If you use a less full batting and a breathable inner layer, you may be able to compress it smaller. You would also notice an increased ammount of insulation if you snugged the ends a little better leaving the center more loose. Excellent beginning on and awesome idea though. This is a project i've been running through my gray matter as well. I think yours is better for compressability. Mine may only have the bennefit of greater durabillity. It mearly involves an outer shell some heavy nylon.