Cuben durability

I'm coming up to about 6 months regular use of my cuben bottomed MLD Soul bivy. Probably 60+ nights sleeping in it so far, mostly on a half length foam pad (with the pad under the bivy, not in it).

No real signs of wear yet, no punctures. I'm really impressed – I wasn't sure it would work out. Cuben is tough!

Aside from the low weight + extra packability, it's nice having a *totally* waterproof fabric for when you're on wet ground and/or a damp pad. Thin silnylon can let water through under pressure, I've had plenty of gear get wet inside silnylon stuff sacks because of this.

Is it necessary to place the pad UNDER the bivy when using one with a Cuben bottom?
Personally I prefer to have the pad inside the bivy, is this not recommended when using a Cuben bottom bivy?

I've always had my pad under it yes. Whether it's necessary or not… I'm not sure. Probably comes down to what sort of ground you're on. I'm only using a torso length pad a lot of the time so it's not like the whole bivy is protected anyway. You'd probably be ok.

Hi Sid,
There are many BPL members that use a bivy with a cuben bottom. I am assuming you will have the 0.6 weight cuben on the bottom? If so, as long as you are careful with site selection, you will be fine.

I use a bivy with a 0.33 weight cuben bottom which is lighter and less durable then the 0.6, but put a CCF pad underneath for protection.

Steven,
Yes I was planning on using 0.6 weight Cuben. I'm getting the impression it would be better to place the pad on the bottom for better protection of the bivy. I guess it makes more sense because, after all, the bivy costs way more than the CCF pad does.

I guess it makes more sense because, after all, the bivy costs way more than the CCF pad does.

Yep, plus if you use the CCF on the bottom, you don't need to bring a ground sheet – dual purpose.

SOmeone already mentioned it I think, but if you carry your CCF on the outside of your pack…it can get a bit dirty and it's nice not to have it inside your bivy.

Actually, I use the CCF pad unrolled inside my frameless pack to help make it more stable. Meaning if I was to use the pad underneath my bivy in muddy conditions, I still have to stick that dirty pad inside my pack. I suppose this might pose a bit of a problem… any suggestions to remedy this?

hmmm, seems you have the exact opposite problem…my advice…carry the pad on the outside. ;) JK, I'll let others respond…

I would not worry too much about the mud. First, I do not think you will pick out a spot that is too muddy, but second you could fold your pad to protect the inside of your pack from it. Third, you could store you folded pad in a plastic bag of some sort. Dried mud is easy to clean off anyway. I am glad you are aware of the different weights of cuben. You might want to check and see what grade zpacks are made from.
Also, if you plan to use an inflatable pad inside your homemade bivy, be sure to allow extra material for the top, so that your sleeping bag will not be compacted by the extra height inside the bivy.

What is the next highest weight in Cuben after .6? Anyone know?

Here is the product information from cubic tech, it is all in grams per square meter though…

That being said, I have not found a source other than the manufacturer for anything besides .48 or .6 (besides zpacks who offers 1.5 but they are closed for business until December).

1.5oz/SqYd cuben (Spectralite) is the next step up. Ron at MLD uses it for the '09 Revelation and will custom make most other gear in the MLD line using it.

I have many pieces of gear made with the 0.6 and have never had a problem with it yet. The items I have in 1.5 (Revelation, Blast 26, and a rodent proof food bag) are incredibly tough.

From looking at the Cubic Tech spec sheet it appears there are actually two weights in between 0.6 and 1.5 but I don't believe any of the cottage manufacturers are using them.

These are roughly .75 and 1.2 respectively.

I got a quote from Cubec Tech for the 1.5 (what they call CT5K.18) at $22.97 per yard but there is a 9 yard minimum order.

I wonder why none of the cottage manufacturers are using the .75 weight.
I think I'm just going to go ahead and try the .6 weight cuben for my bivy bottom. I haven't heard anyone complain about its durability yet.
Also, an off topic questions… Is .6 weight Cuben lighter than mesh? I'm referring to the standard mesh used for bug netting, I'm not really sure what it weighs. If anyone can answer this I'd appreciate it. Thanks.

-Sid

I'm referring to open mesh of course, not the spacer mesh commonly used on backpacks. Anyone have an idea if cuben is lighter??

Yes .6 oz Cuben is lighter than both noseeum and nanoseeum 1.1 oz and .7 oz respective.