insulating with foam sheets

[Albert Skye]

I used a nylon mesh [...]

There you are! Did you ever try noseeum net? An expanded mesh could be made from that as well. Need testing...

I took a 60" x 60" piece of Insultex and [...]

You're quick! I think a geometry more like the one in the picture in my initial post will give better performance (i.e., insulation:weight and insulation:volume).

You should slit it in the direction of the strength.

I'm not sure; it might be better to use perpendicular orientation to minimise elongation (i.e., lengthening of the slits by tearing).

[MacEntyre]

...ever try noseeum net?

No, I never tried anything else before implementing InsulTubes.

My preference is to have the thing that provides the separation be something that also provides insulation. Mesh provides only separation.

[TiredFeet]

What exactly is your intended purpose for the expanded foam mesh?

To provide separation only? or added insulation?

[WV]

You're quick! I think a geometry more like the one in the picture in my initial post will give better performance (i.e., insulation:weight and insulation:volume).

I agree. The center piece of Ix with the slits is heavier than the flat top and bottom pieces, but the total weight without rigging is about 11 oz., and I'm okay with that.

The speed of execution is because I'm backpacking with a friend next week and I want to lend him a hammock. He's too tall for my hammocks, so I made a quickie Speer type, and I was just wondering what to do about bottom insulation when I saw your post. Thanks!

I tested the tear strength in both directions as Mac suggested, and he's right, it's definitely stronger in one direction. Fortunately for me that complements the slit pattern I chose - cutting the long direction of the diamond.

[Albert Skye]

My preference is to have the thing that provides the separation be something that also provides insulation. Mesh provides only separation.

As it appears to me, insulation and separation are distinct. They are combined in a pleated sheet, and I see no reason not to combine them *if* it incurs no significant loss of efficiency.

I think we agree that the separation layer should minimise conductive heat transfer. A separate separation layer has less thermal coupling. Mesh reduces convection.

The center piece of Ix with the slits is heavier than the flat top and bottom pieces [...]

Cut some more slits; it should be much lighter.

[MacEntyre]

Cut some more slits; it should be much lighter.

I don't think he is removing material, just slicing... which allows it to stretch.

Now, if Dave were to pleat each diamond separately, instead of slicing, he would have a superior middle layer!

[Albert Skye]

I don't think he is removing material, just slicing... which allows it to stretch.

Yes, more slits -> more stretch -> greater area:weight.

Now, if Dave were to pleat each diamond separately, instead of slicing, he would have a superior middle layer.

I'm not sure what you mean by "superior" but I think warmth:weight and warmth:volume would be lower.

[WV]

Cut some more slits; it should be much lighter.

I don't think he is removing material, just slicing... which allows it to stretch.

Albert, it's heavier because the middle layer started out 60" x 60" (i.e. 3600 sq. in.). Cutting the slits enabled me to stretch it to approximately 45" x 75".
The top and bottom pieces are flat 45" x 75" (3375 sq. in.). Of course, if I had cut the slits closer together, I could have started with a much smaller center piece, but I didn't want to cut that many slits. As it is, the "loft" may be as much as an inch, which will perhaps compress to 1/2". I'll see how that works.

Now, if Dave were to pleat each diamond separately, instead of slicing, he would have a superior middle layer!

Thanks, Mac ....

[Stovemandan]

Using a separate layer of expanded mesh made from foam sheet seems promising. It's labour-intensive (though easily tooled once the dimensions are optimised) but I think it would work well.

What thickness of foam sheet are you thinking of expanding 1/8"?

1" O.D. leather punch will work. Affix it to a hammer handle and whack away.

I would think slits would just compress sideways

[MacEntyre]

I just meant that individually pleated diamonds would be superior insulating separators to individually slit diamonds. The opening provided by the slit works against reducing heat transfer.

I'm sorry, Dave! Your approach is intriguing!