Pad insulation longevity

[Stephen M]

I second what Eric posted.

[Paul S.]

Eric,

I’ve had it long before I learned that synthetic insulation degrades. I don’t recall any labels warning me on proper storage so didn’t give it much thought at the time.  Am I supposed to hang it lIke my quilt?

Personally I don’t worry much about the insulation but my wife has the same pad (not quite as old but look identical so hard to tell which is which) and she sleeps much colder and I’d hate to be giving her a underrated pad.  I have considered upgrading but they’re comfortable, heavy, but not much heavier than other insulated pads (that and new pads are pricey), but if they have lost their warmth it’s time to upgrade.

[Arla Hile]

I had one of the early Thermarest pads (bought it in late 1985 or early 1986), and that darn thing was still going strong until I decided I wanted something lighter and more comfortable for my old bones, and I gave it away to a newbie hiker. Damn I just realized that’s about 30 years! This includes sleeping on it every night during a 6-month-long bicycle trip, plenty of backpacking and car-camping trips, and a patch here or there. Anyway it was still plenty warm, although I always took care of it – stored it slightly inflated from day 1.

[Stephen M]

Folk recommend to keep pads under a bed stored flat, I am unable to do that so store them inflated against a wall in my gear closet.

 

[Tipi Walter]

Arla Hile says

“I had one of the early Thermarest pads (bought it in late 1985 or early 1986), and that darn thing was still going strong until I decided I wanted something lighter and more comfortable for my old bones, and I gave it away to a newbie hiker. Damn I just realized that’s about 30 years! This includes sleeping on it every night during a 6-month-long bicycle trip, plenty of backpacking and car-camping trips, and a patch here or there. Anyway it was still plenty warm, although I always took care of it – stored it slightly inflated from day 1.”

So I think we’ve determined that Thermarest inflatable foam does not deteriorate over time.  When you say “Damn I just realized that’s about 30 years!”, well, it precisely echos what I said on an earlier post.  I guess you have to hear it from people other than me to believe it.

So the next question becomes, if the inside foam does not die from age, what does kill a Thermarest inflatable??  Pinholes, valve leaks, delamination bubbles.

Here’s the real cause of Thermarest failures:

Putting the blasted thing exposed on the outside of your pack.  And then people wonder why they have a slow leak and hard to find pinholes.  This pic was taken on a recent September backpacking trip into the Cohutta wilderness.

And I’ve seen people fold their inflatables into chairs or throw them on the ground to sit and wonder, “Gosh darn, my crappy expensive Thermarest leaks!!!”  No, you caused it and it was pilot error.

[Stephen M]

I see that all the time.

Its nearly as bad as seeing a loose axe dangling off a pack.

[Sam Farrington]

So am wondering from the posts if it’s become much harder to access older articles with this redesigned site. Editor Roger Caffin has done articles on pads. One was on so-called self inflatables, and dealt with issues of degradation. He related that he and his wife store their pads hung up with the valves open to let any moisture from breath evaporate and avoid long term compression of the foam.
Will have to try to access some of BPL’s classic articles and see how difficult it may have become. It is that reservoir of great articles and threads that add the most value to this site, IMO. Not that I have anything against chat rooms, FWTAW.

[Gator Paddler]

It would be great to see some data on this. Is there someone here who has the a setup for measure thermal conductivity?

It would also be great if there was a standardized procedure for testing r-values for sleeping pads. Exped revised their values for their latest pads after a production run. By the way, I tried a winterlite and returned it because my wife and I found it completely uncomfortable. I replaced it with a discontinued downmat ul7 and am really glad to hear they are bringing them back.

[Tipi Walter]

I don’t even know how to pronounce “measure thermal conductivity”.  The absolute best procedure for testing r-values on a sleeping pad is to pick a cold night at home and sleep with it in the backyard every night for a week or two. Preferably on snow.  No need to run a spreadsheet or acquire data points, etc.  Just use the things in real world conditions and go from there.

When I look at the new lineup of Thermarest pads (and yes, they change model names almost on a monthly basis—what was once the Camp Rest has—abracadabra!!—become the Base Camp—I check first if the pad is available in large 25 inches wide, thickness (2 inches favored), Rvalue (at least 4R), and weight.

Someone needs to write a short history on the Thermarest brand and come up with all the pad names they have discontinued.  No wonder newbs get confused.  I can name a few—

Toughskin—gone.  Standard (orange with metal valves)—gone.  Camp Rest as mentioned.  Ultralight—gone.  Classic—gone.  40th Anniversary—gone.  Trail Guide—gone.   Backpacker model—??? who knows?  Explorer model—???.

So you have to learn all new names with upgraded versions.  It’s okay, I always find suitable replacements.

[Jerry Adams]

Roger wrote an article measuring the thermal conductivity of sleeping pads, but I can’t find it

I wrote an article about measuring a 1 foot square of sleeping bag but not sleeping pads

[Tipi Walter]

Like I said, just throw your pad on the snow and have at it and try to get some sleep.  I was raised by a college professor and I know all about studying a subject to death and so I have minimal interest in gear specs or tabulations or thermodynamics or sublimations or all the rest.  I leave this up to the engineers and designers of the gear I buy—then I use it in the field.  If it works and remains in my Circle of Trust for several years then it works and I don’t care how it does so.

I don’t think a backpacker or an outdoorsman needs any kind of indepth analysis to pick gear and certainly minimal study to use it in the field.

[Jerry Adams]

“I leave this up to the engineers and designers of the gear I buy”

I like Roger’s article about the winter blend canisters.  They have no engineers or scientists.  And there winter blend canisters are mostly just marketing spin.

But part of what’s fun about studying is the geekiness of it.  You don’t need to study it that much unless you’re just into that.

But, if you can make your pack a few pounds lighter, and be just as effective, it’ll make your trip more pleasant.  Maybe you can continue doing trips as you get old or injured.  Studying this helps.

Anybody can build a bridge, but an engineer can build a bridge that’s cheaper and lighter that just barely stays up.

[Tipi Walter]

The engineers at Western Mountaineering or Feathered Friends are excellent so I let them do all the work.  The clever designers at Mystery Ranch make some awesome packs.  My Arcteryx rain jacket was put together by geniuses.  Amen.  But I have no interest in the history of microfiber or grams-per-sq-inch or what plastic Fastex uses for belt buckles or the specs of ProShell or the current state of Cordura in America, I just want to use the stuff for a 3 week trip.

[Gator Paddler]

How will sleeping on a mat today or tomorrow tell me how it will hold up to a month or to a year of repeated compression cycles? I would like to know about the durability of insulation in pads, but I think your (Tipi’s) point about other durability issues is more pressing. Still, we pay a lot of money (sometimes hundreds of dollars) for these pads, so i would like to make the most informed decisions possible.

One of the things that drew me to become a lifetime member were the reports by members who actually do testing of gear. The gear manufacturers don’t seem to want to tell us how they are testing them, so it would be nice if someone would…

[Tipi Walter]

Gator Paddler—You bring up a HUGE point and a sore point about gear reviews—the stuff is rarely tested to failure and THEN afterwards the test review is written.  A huge percentage of gear reviews are not long term at all—like 200 or 300 nights with the thing.  By then of course the item is replaced by the company with a new model and a new name.

I love reviews like this ” I used my wonderful NeoAir for a weekend trip and it’s the best pad on the market!!”.  Uh, maybe not.

Sleeping on a pad tonight in the backyard at 0F in the snow will only tell you if it will keep you warm for the weeks you do the backyard test—it will not tell you anything about long term reliability or durability.  But we already discussed this—I find I can get about 180 to 250 nights out on a sleeping pad before it is replaced, often not for failure but as a precaution for failure.

In other words, if you find a sleeping pad you like and it works at 0F and is comfortable, (and it’s a Thermarest), it should last with care for around 200 nights before replacement due to pinholes, valve leaks or delamination.  Don’t strap it to the outside of your pack unprotected, don’t throw it on bare ground for a sit pad, don’t use it in a chair by the fire.

In this vein we had a discussion about gear and what’s in your Circle of Trust, i.e. gear tested thru time and tough field conditions—

http://www.whiteblaze.net/forum/showthread.php/101376-Outside-Your-Circle-of-Trust

[Rex Sanders]

Tipi Walter writes:

Along with a Thermarest design system unable to solve this problem, even after 35 years.

Maybe they don’t want to solve this problem.

— Rex

[Tipi Walter]

Rex—You may be right.  Surely glue technology has improved in 35 years?  What about fabric-to-foam welding technology and not glue???

Case in Point:  The old Exped downmats were fine, excellent, superior, warm and comfortable backpacking pads.  Except for one thing:  They had a nasty tendency for the down pad baffles to delaminate.  See—

Here is my pic of the problem—sadly on Day 1 of a 19 day winter trip.

Not my pic but it shows the same problem.  Pic from—

http://travellingtwo.com/12882

Okay, problem discovered.  What does the company do?  They go to Plan B—

They go to individual down baffles that cannot rip—from their Downmat TT 9 model.

And so the whole config looks like this.  YIKES.

All this just to improve their plastic seam weld technology??

[D M]

Wow, I’d never seen THAT picture before…..looks like a monster of added ounces…that’s not a solution, that’s and excuse for not fixing the problem.

I love Engineers, my kids are all Engineers. One is medical and the other mechanical. Two of them are getting married in the spring and every detail is on spreadsheets….I love how they beat every possibility known to man with a stick. :-) Personally I rely on my own gear testing, as I’m outside sleeping on the ground at least six months of each year, and other long trail hikers like myself who really, really use the cr*p out of gear. German Tourist is one who’s tested stuff to the max. And there are compensations made for durability vs weight. I’ve been very lucky but also very careful with my pads, I can’t afford to be going through gear like crazy, it HAS to last. If not I end up sleeping on whatever I can find in the closest town or get shipped to me.

[Tipi Walter]

German Tourist speaks of inflatable pads delaminating and she does push items to the limit—

http://christine-on-big-trip.blogspot.com/p/what-breaks-when-and-why.html

I got to meet her in the Big Frog wilderness as she was pulling her AT/BMT winter trip—

[Tipi Walter]

More German Tourist thoughts—

http://backpackinglight.com/forums/topic/74891/

http://backpackinglight.com/forums/topic/88207/

http://backpackinglight.com/forums/topic/59312/

[Ian]

OP,

If I understand you correctly, you’re more concerned about synthetic insulation degrading vs open cell foam.  I haven’t used my Exped Synmat enough to say but anecdotaly, from what has already been mentioned on this thread and several before this, these pads tend to delaminate before that becomes an issue.  I don’t know of a synthetic insulator that’s immune from degradation if stored or handled improperly although they are rolled up pretty tight when packaged and seem to be fine new out of the box.

I don’t even know how to pronounce ‘measure thermal conductivity’

Ha!  This made me chuckle.  I identify.

The absolute best procedure for testing r-values on a sleeping pad is to pick a cold night at home and sleep with it in the backyard every night for a week or two. Preferably on snow.  No need to run a spreadsheet or acquire data points, etc.  Just use the things in real world conditions and go from there.

I completely agree.  Sure it’s great to compare R values when shopping but the proof is in the pudding and for my money, nothing beats hands on experience.

I’ll +12 that while not immune from delamination, TAR’s misnomered self inflating pads are one of the more durable inflatable options out there.   I’ve also owned the circa 198something big orange w/ metal valve pad and have gone backpacking with it as recently as three years ago (before going UL) and it was in near perfect condition when I donated it to the Boy Scouts this past spring.

The military started issuing TAR self inflating pads in the ’90s.  As a grunt, we would throw it on the ground with no ground sheet.  I’d have to patch the occasional hole but it was not anything I’d consider to be a high maintenance item and it survived the worst I could throw at it.  Someone forgot to tell us that a <R3 pad was inadequate for winter as that’s all we had at Ft. Drum, NY.  I’m sure we saw temps below -20*F but that was the coldest temperature I could confirm.

I’ve yet to have an issue with my 3/4 prolite pad, which is the one I use the most, but I also don’t have as much time on it as my USGI version.

Much of this has drifted away from what the OP was asking but it’s an interesting conversation.

[Brad Rogers]

The BA Insulated Air Core was often accused of being overrated at R 4.1.  I bought one for car camping trips and I found it colder than my Thermarests of lesser R value.  I remember seeing a PIC of one someone cut open and it was a very thin piece of insulation.

Eric is right, you should never store an open cell, down, or synthetic insulated mat rolled up.  Neoairs are OK.

 

 

[Stephen M]

My buddy was using a BA insulated Air Core last week in 15f temps and he found it a bit chilly.  I had told him to pack a foam pad but he forgot it.  In the morning when we were packing up he commented that the snow had melted under where he had slept, and had not where I was sleeping (I was using an r6 Synmat UL 9 and Ridgerest).

I must presume the BA pad leaked a lot of heat the ground.

 

 

[Matt Dirksen]

”

Tipi Walter writes:

Along with a Thermarest design system unable to solve this problem, even after 35 years.

Maybe they don’t want to solve this problem.

— Rex”

+1

In my opinion, they solved it years ago, but continue to “tinker” with the newer and lighter materials, in the hope that us consumers will be tantalized to buy something new from them again. As we all know: not all “Lifetime Warranties” are created equal.

Having sold hundreds of T-rest pads back in the 90’s I don’t remember a single delamination issue (just valve issues.) Of course the open-celled foam design was quite simple back then, and had a lot of “surface area” for the glue to adhere to. For car camping, my family and I still use 20+ year old “Luxury Edition” pads. I have always stored them rolled up. And (knock on wood), they work every time, and are still the best balance of firmness and “cushiness” that my back desires. And with the fleece-like surface, they work great in the warmer/humid months toward absorbing/evaporating unwanted body moisture.

As I said before, it is my understanding that there are no industry standards for sleeping pads for establishing R-value. Furthermore, I suspect there are no agreed standards on what defines “normal wear and tear” to the manufacturers. Perhaps if we send hundreds of “bitch” letters off to them, they will get their collective act’s together.

(Of course, only if it’s in their economic interest!… sigh)

In the meantime, I’ll stick to the  “rules of thumb” long established by the beloved and experienced BPL’ers on this list, and use a ccf pad in the winter in conjunction with whatever to make it more comfy for my aging back.

Matt

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