IPassGas

Does anyone have knowledge of the materials/construction used in lightweight air sleeping pad construction to hold the air in?

Over the years our air pads have failed in different ways. Two of our new air pads have failed because an inner membrane layer separated from the outer fabric shell. Such a failure cannot be patched, at least not using the supplied patch kits. I suspect (a guess) that some air pads use fabric impregnated with some type of urethane (think of Ortliebs) versus some pads that use a laminated membrane. The former can be fixed with patches, the latter cannot if the leak is due to delamination.

Possibly new pad technology uses a membrane to lower weight, if so, I want to identify such pads and stay away. I want to be able to patch a pad in the middle of nowhere. Are there different material/construction to hold air in pads? Difficult to know since this is proprietary information.

tombc

I was daydreaming about this for a while, then bought a Nemo Switchback which is a lot like a Z Lite

djb

I can't help with this question, but I strongly suspect that the main cause for delamination issues are from over inflation and leaving the mat in a very hot tent, or in the sun, causing the mat to balloon up from the increased pressure from heat.

​​​​​​I've observed this numerous times over the years.
touch wood, my neoair has been good for the years that I've had it, but I'm particularly careful about a hot tent or sun.

gauvins

​​​​​Not obvious. ThermaRest writes that delamination is generally attributed to a manufacturing defect and that they'll usually replace the pad under their limited lifetime warranty.

My pad suffered from delamination. I could not think of a reason for this, other than wear and tear. And even though the lifetime warranty is impressive, it doesn't solve the very real problem of sleeping on the ground until you can find a replacement. I've opted for closed cell. Not clear what I'd do in colder weather -- I'd probably use my xTherm. Delamination being progressive, I'd assume that it could survive the trip or I'd find a replacement before it'd become useless.

djb

That's a great thermorest article, I'm going to keep that for future reference, thanks.
As you say, and they do, there are multiple reasons.
My comment comes from seeing camp mats becoming like marshmallows, all puffed up and bloated, from excessive heat--it can't be good for the parts glued together inside.
Your idea of using a closed cell mat underneath sounds like a really good idea. When I got my neoair, the increased comfort over many decades of traditional self inflating thermorests was really really noticeable. This is why I am so careful with mine.

I also see people putting them outside against trees, on the ground, and generally but being careful, with them.

My personal experience with delamination with an older style thermorest , was that it was a slow process, so yes it appears to be gradual. Holes due to uncareful tent placement over sharp plants or whatever, is a different risk. Being careful inside the tent with sharp objects etc too is just common sense, so I find it very hard to discuss risk assessment for air mats simply because different people treat things in such different ways.
And some people are just tough on equipment and don't use common sense.
No matter the cause though, especially with a cold weather trip like you are considering, you sure as heck want to be sure of your sleep system, just like your choices of clothing, as you have been asking about lately.
I'm a skinny guy who gets colder probably more than others, so completely get that.

Thanks again for that great article.

IPassGas

Yes, thanks, that article is useful. I now know of 2 major pad makers that use membranes. It may be that all air pads use membranes, don't know. We always sleep with a thin layer of clothing to protect the sleeping bag, and according to this article, also protects the air pad. In general, we treat our air pads with much care. Our older expeds never had a membrane delamination problem. Also, the experience of many of our friends with exped. But we gave up on exped due to the baffels coming unglued on several. So I still wonder if some air pads use urethane-impregnated fabrics rather than a membrane.

djb mentions that excessive heat might be a problem. Perhaps, and I imagine that heat could also damage the membrane bonding over time, but we always inflate our pads after coming into camp.

While a PITA, I am ok with patching a pad...a soap solution and sponge from the cook set work well in finding it. But, when a inner membrane de-bonds and tears, it is impossible to repair.

IPassGas

In our younger days, we had many wonderful backpack outings and tours with a Z rest. But with age, neither of us sleep well on foam, and it is too bulky.

djb

I'm certainly in that crowd now of not really having much of an urge to go back to a foam pad, really appreciate an air pad for sleeping partially on my side. Lots of quite good, light options. Just not cheap, but avoid a hotel night or two and you've paid for a good air pad.

IPassGas

Very true. Good sleep is so important. I would pay much more for "a good air pad". I'm not sure a good air pad exists, and the comments from people going back to foam supports this notion. Weight is secondary, pads with higher thread count (if that means less punctures), and most importantly, can always be repaired in the field. The lifetime warranty thing doesn't help much in the middle of nowhere. I wish manufacturers would respond to this need, stop with the "ultra" thing, and focus/market durability. But then, this is the sort of rant that touring on a bicycle can bring on

djb

For the record, my very early model neoair is comfortable, and has been fine for about ten years, so I have no complaints.

staehpj1

Between my family, friends, and acquaintences there have been a lot of nights on inflatable pads. Only a very few unrepairable defects have occurred. Those were all of two types:

1. The newer neoair style pads had a few internal baffle failure. These were relatively rare and never were a complete failure in that they lft the user unable to sleep on them until they could get a replacement. Worst case, on a long trip they might need to sleep on it a few nights and buy a new pad if it is a long trip. I slept on the lump for a week or so and it wasn't bad. The lump starts small and builds so you really aren't likely to have to go without a pad. Some have repaired pinholes, but they are surprisingly infrequent.
2. The other type of fatal failue I recall was with the older selfinflating pads. They were sometimes impossible to effectively patch if the failed at the seam. I have not used this style pad in decades other than a huge basecamp one that I sometimes use in the back of a vehicle.

In general the pinholes in either style are easily avoided and easily patched in my experience. My neoairs have never needed patches. My self inflating pads seldom did. Some folks apparently have worse luck in that regard.

BTW, windex is great for finding leaks in inflated or pressurized items of all sorts including bike related stuff.

IPassGas

Thanks, your experience with neoair is helpful. Our older expeds also suffered from baffle failure many (4) times. And your assertion that baffle failure is not devastating (word?) is correct. We gave up on exped owing to the multiple failures, but now I wonder... We switched to Klymit and then experienced membrane separation problems in two pads which caused an intimate awareness of the ground for a long time on tour. I love Mother Earth, but she can be hard. We have new klymit pads from warranty, maybe will work, but I understand why some people have given up on air pads. If the klymits fail again, we will switch to either exped (perhaps their new line has fixed the baffle problem) or neoair. I can deal with baffle problems.

Windex? Never thought of that. I find camp suds to be sufficient.

djb

that number of failures really does seem very high. The pragmatist in me wonders if there is some sort of user failure going on, either how you use/treat them, or some sort of other factor that comes into play (storage, exposure to something??)

as for staes thing for Windex, he's actually that Greek dad from My Big Fat Greek Wedding, so it's no surprise that he says that ;-)