Jul 2, 2008 at 2:08 am #1229958
I think this thread is gonna be fun!
MYO isnt impossible as was demonstrated by the fifth-grader. But he was able to make just 1-1/2" by
5-1/2" irregular pieces. Making uniform sheets is probably not possible at home. An there could be an
advantage with using granular aerogel.
Here my idea:
>Make a SUL sleeping bag shell of silk
>Apply adhesive on the entire outer side
>Then uniformly sprinkle aerogel on the glue. You will need a lot of aerogel!
>move your hand over the aerogel layer. If you feel the glue add aerogel on that spot. Keep doing till if you find no sticky spot.
>You may need another silk bag as outer shell.
Although I havent tried this I dont see why it wouldnt work.
Another great thing about aerogel sleeping bag is that you dont need a insulated pad with it. You can get away with a sheet of bubble wrap placed under you inside the sleeping bag.Jul 2, 2008 at 4:06 am #1441140
This is funny, i've thought about this before as well. This is going to be so outrageously expensive with materials and equip and all… some big gear mfg w/ a big $ r&d dept is going to have to have a go at this one. Can you imagine any kind of glue/epoxy that would bond aerogel to fabric (doubtful). Seems like you will have to use insanely small baffles.
Maybe a sleeping pad w/ small slabs or stove/mug insulation would be more practical. This is way too far out, nobody is going to do this and come up with a usable bag (prove me wrong!)Jul 2, 2008 at 5:32 am #1441143
I say do it. You can buy a liter of the granules for $35 from that small place. I'd image you could get a lot more for half of that.
I think you should make a really thick baffle filled with it on the bottom. Make it like a bean bag chair on the bottom side. You wont have to carry a pad. That would be funny.
Biggest downside is that it wont stuff. No compression by the nature of one of it's best properties. Maybe you could fill the rest of the bag with helium and tie a string on it instead of packing it ;)
I can see it now. A cuben and aerogel bag. You would look like one of those lollipops with the bug inside.
BTW: Make sure you get a hydrophobic version of the stuff. Aerogel is hydrophilic without treatment.
Edit to add link:Jul 2, 2008 at 11:32 am #1441197
@finallymeLocale: Utah desert
Yeah, the biggest problem is that it won't compress. The bag would be huge and expensive. Down is cheaper and compresses. I thought about using a blanket, but those are really heavy. For some reason, making aerogel flexible adds a lot of weight.
Also, if you use an epoxy, it would stiffen the fabric, and probably negate any weight savings from the aerogel.Jul 4, 2008 at 9:55 am #1441491
>this is going to be so outrageously expensive with materials and equip and all…
I am not sure how much aerogel would be required for the sleeping bag. United Nuclear sells 950cc Aerogel for $35. It isnt that expensive. An aerogel sleeping bag may possibly be cheaper then down sleeping bag.
>Can you imagine any kind of glue/epoxy that would bond aerogel to fabric
Aerogel is made from Silicon Dioxide, the same material as ordinary Glass. So I think any epoxy that can bond glass to fabric would be able to bond aerogel to fabric.
>Make sure you get a hydrophobic version of the stuff. Aerogel is hydrophilic without treatment.
I will contact UN to enquire about that.
btw does anyone have any idea if absorbtion of moisture by aerogel affects its insulating ability.Jul 4, 2008 at 11:29 pm #1441558Jul 5, 2008 at 5:47 am #1441568
After some calculations I realised that a layer of aerogel granules will not provide much insulation. Aerogel has R value of 10/inch that means a clo value of about 11.36
A 30F bag with clo value of about 5.68 will have to be about half inch thick. Uncompressibility of aerogel is sure a valid point now. I would personally chose smaller volume over less weight anyday.
I think I was also wrong about the cost – a half inch think bag would be very expensive. Not sure if I can even make a half inch bag from granules.Jul 8, 2008 at 10:16 am #1441990
I had emailed Polyformes Ltd, UK a few days back to enquire if they sell spaceloft in small quantity. The do! I just got their email.
After a lot of thought it seems to me that aerogel has more benifits when used as a pad then as a sleeping bag. A foldable design such Nightlight torso would be really cool. Check out the link Patrick posted above.
At R value of 10/inch, a 9mm or .35" spaceloft pad will have a R value of 3.5. Comparingly, 3/8" or 9.5mm thinlight has R value of just 1.42!Jul 8, 2008 at 5:10 pm #1442064
Think there might be more value in a pot wrap than a sleep pad. Those blankets don't look light or squishy. Do you have data on them?Jul 8, 2008 at 11:03 pm #1442095
Here is the link to the spaceloft datasheet PDF:
Spaceloft has a density of .15grams/cc. Approximating 9mm spaceloft as 10mm for ease of calculation, a 150cm x 50cm pad (smae dimension as thinlight) will weight 1125 grams…. 9mm pad will weight 1012.5grams. You were right, its heavy.Jul 9, 2008 at 11:32 am #1442172
@ckrusorLocale: Northwest US
I've been using Aspen aerogel blankets to make multilayer insulation for instruments and vessels at the lab where I work for a couple of years, and I aquired a large piece of Aspen's Spaceloft and experimented with sleeping pad designs about eight months ago. I reported all of the details and carried on some discussion in a dedicated thread:
Aspen's aerogel blankets are very dense compared to typical sleeping pad foam. I tried using the lowest density product Aspen makes, the Spaceloft 6250. It's only 6mm thick but close to 20 ounces/square yard. A torso pad would be half a pound before encapsulation. The fibrous mat in which the aerogel dendrites are formed is like heavy industrial felt. They can be peeled apart to give thinner sheets, but this causes a good deal of the entrapped aerogel to be lost as clouds of fine, choking dust. Flexing the blanket also produces a lot of dust. Any place that folds soon loses all it's aerogel and becomes just a polyester mat.
Also, a lot of research has gone into the use of aerogel-based multilayer insulation for underwater pipelines, where compression of the insulation is a problem (as in sleeping pad design). The aerogel is a bit like that brittle green foam often used for artificial plants. Under compression it mashes down irreversibly. It's not elastic. In the studies I read of pipeline insulation the compressed aerogel doubled in density and lost half its initial insulation value.
I think an aerogel sleeping pad competitive with plain old EVA foam in performance would need three things: a shiny IR reflective envelope (aluminized mylar, for example), evacuation (to below 10 torr), and incompressible posts (maybe syntactic silicone foam) to protect the aerogel from compression.
Ultimately you'd get a very expensive, fragile, complex system that probably wouldn't beat EVA by very much.
It wouldn't suprise me a bit if one of our little MYOG community came up with a way around these difficulties, though. I don't want to shoot anyone down. I think powdered aerogel (pulverized granules), vacuum sealed in tiny (1/8 inch) tubelike parallel baffles, might have promise for warm, lightweight, waterproof gloves and hats.Nov 5, 2008 at 4:14 pm #1457723
Dude get a food vacuum sealer on ebay and get some granular aerogel. When the bag compresses it will hold all the granuals together and water tight.You could have a bunch of cells on either side filled with argon gas so the areogel wont be crushed under weight. Cant wait for winter!!! ForrestNov 16, 2008 at 8:40 pm #1459237
The only thing I could not get around with the glue (epoxy, whatever) is breathability. If all you are making with the stuff is a VBL, there are cheaper ways! :p
I so love my down, but after so many years of leading the industry (weight, compressibility) I cannot wait to see the next big thing!Nov 21, 2008 at 5:26 pm #1460091
If I understand correctly, Aerogel has some interesting and unusual properties:
1) High insulation for the thickness
2) Very light for the amount of insulation
3) Doesn't compress
5) Has to be wrapped in something
The first and third item make it very unusual. Most insulation (down or puffy synthetic) gets its warmth from trapping air. Thus, the only way you can get decent warmth is by making it thick. On the other hand, the lack of compressibility (when packed) is a big drawback (as mentioned). When these two factors are combined, some uses make a lot of sense. For example, shoe inserts. You certainly don't want to make an insert too thick, nor do you want it to compress (a down insert makes no sense). In this way, it more resembles thinsulate, or neoprene.
Of course, the last two items make things difficult. Since it needs to be wrapped in something, you either wrap it in an air tight bag (which is the simplest, but makes it almost useless as far as body insulation) or as Huzefa originally proposed, a breathable container. I like the sleeping pad idea (I know some company out there makes one) because you don't have to worry about breathing. I would imagine you could have a thin layer of the stuff surrounded by a thin closed cell pad (an aerogel sandwich on closed cell foam). I would design it like the Z-Rest, so you can fold it up easily. I think such a pad could be fairly small (when folded up). Such a folding approach would lessen worries about shifting pellets (if you roll a pad, your squishing it longitudinally which could cause problems). Such a pad would work well with another pad (the aerogel pad would be primarily for warmth allowing you to reduce overall bulk by carrying an additional inflatable for comfort).
There are probably other uses out there for this stuff, but dealing with its unusual properties requires a lot of thought and creativity.
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