MYOG Sea to Summit Ultralight Insulated Pad modifications

[Adam Kilpatrick]

So, plenty of people have modified Neoair pads over the years to their desired length. That mat has a fabric is a TPU fabric, ie, its heat sealable. (Eg see Suluk46’s Steve Evan’s early videos on the subject).

I never liked the Neoairs, I’ve tried and owned a few but could never quite get comfortable on them. They felt too balloon like to me, too noisy, and were too high; I had the classic reported issues with arm overhang (feels weird with your arms coming off the side trying to make their way to the floor), and also leg over hang on the shorter pads (I bought the shortest manufactured length and that was bad enough, let alone modifying to a shorter true Torso length). I could never get my favourite pillow (Big Sky dream sleeper) to work well with them either-on the pad meant I lost length and the drop off with my legs was worse (also I had to deflate the pillow a bit, annoying), off the pad at the head end and the crazy thickness of the NeoAir made my pillow far too thin!

I love Torso length pads, and have a large amount of experience with them now. I have various-first was a cut down CCF a long time ago, a BPL (Bozeman Mountain Works) Torsolite (great pad but certainly pushing the comfort dimensions), an XS TR Prolite (sensational pad, I have about 300nights on it), GG Torso pad, a Cascade design works similar version and various thinner ccf/evazotes…

I looked at the S2S pads, and tried one ages ago in a local store. Very comfortable, but seemingly heavy! And no true short option available! The short option is 168cm inflated-its essentially full length. The way they have done the matrix of “cells” is fantastic, it really is a comfortable experience. Being half the thickness of a Neoair, there are no issues with dropoff.

Its a TPU heat sealable pad. S2S brags on with marketing about their fancy proprietary sealing machine doo dad. This had me a tiny bit scared but was hoping it was just marketing hype. Surely a hot iron and careful pressure would do the same?

So last night, I took the plunge.

Initial Pad: S2S ultralight insulated, short: 168cm inflated. R3.3 (spec). Weight (measured): 425g.

Resultant Pad: 105cm inflated. 280.6grams (just under 10oz).

Finished pad next to XS Thermarest Prolite

I sealed the edges about 10mm wide-about three times the original seams. I think this was definitely overkill on my part. I did test runs on the offcuts, and was instantly reassured that this would work. A small 2cm seam on an offcut…I couldn’t pull it apart at all, so peel strength is very high (I can deadlift over 150kg…). I’ve zero doubt this will hold up long term, in fact, my seams are probably stronger than manufacture!

Test seal on scrap

My optimised torso length, with pillow off the pad, I think is 88-90cm. This one I did a bit longer first try…I was a bit worried about the seams (still, after test). But I could save about another ounce by going down to that length. With the taper, and the insulation layers inside (which are also tapered and not full length) its a little hard to accurately calculate the resultant weight. I think for now I will stick with it, and see how I go, and maybe shorten it in the future, or do the same treatment on their ultralight non-insulated pad but to 88cm, for trips where I know the temp will be above 5C (~40F).

Insulation remnants-you can see the reflective layer, which is lightly glued to the ~10mm insulation layer. S2S don’t do a pad with either or, its either both or nothing (non-insulated ultralight version). Be good to see them do a more optimised pad for weight that is short and maybe just has the reflective barrier. This is definitely a warm pad (r=3.3, might be conservative, it feels like an Xtherm).

Oh yeah, resulting packed size is a little less than my XS Thermarest-about 1-2cm shorter and slightly thinner diameter. Despite the extra length.

Go forth and chop chop chop away BPL!!!

 

[Adam Kilpatrick]

Some further notes:

 

Inflate to measure your required length! Ballpoint pen marks this material nicely.

No issues with the cut edge/wrinkles. I cut it pretty precisely-cut completely deflated, use very sharp scissors. When you hit the insulation it gets harder and you have to be careful. Have to be a little careful with wrinkles but not too much of an issue. Just be gentle, move slowly by lifting the iron as you go. Super hot setting on your iron, no steam. About 15second presses I did, I went back and did the opposite side to make sure. Where I thought there might be slight wrinkles I gave it extra hot pressing at the end just to make sure. I was being paranoid. Make sure your cut is either straight or nicely curved-this will help with preventing issues with overly stressing a seam and/or wrinkles in the sealing process.

 

[Adam Kilpatrick]

Useage review:

I’ve now put about ten nights sleeping on this pad. Works perfectly! No issues at all with my seal, and I’m never expecting any.

Also I got the length pretty good. I was musing making a shorter version, kinda like the length of my XS Thermarest at around 88cm, but I think this length is fine. In a couple of years I might do a shorter version using the less insulated version of this pad, for conditions above 10C.

[todd]

Man for that weight I wouldn’t shorten it!  But this IS BPL, eh?  :)

Thanks for the pics & taking the plunge.  Great pad.

[Nick Smolinske]

I was going to start my own thread, but I might as well add to this one.  I’ve now cut and resealed the following pads:

1. Klymit Static V (75d polyester w/TPU laminate) – cut down to dog size this past month for a CDT section.  Yeah, he’s spoiled.
2. Klymit O-zone (also 75D poly) – cut down to torso size.  need to put this one up for sale.  Or maybe cut down for a possible future additional dog?
3. Exped pillow (regular, not the UL pillow, 50D nylon w/ TPU) – I cut this down to reduce the excessive size of the under-the-neck part of the pillow.  Much more comfortable now.

I’m going to do another one soon, an Exped airmat lite 5.  Down to torso-to-knees size for summer use.  For all of these I’ve used an iron on the max setting, hold in each spot for a few seconds, no steam.  Never had any problems and I’ve used them enough to trust them totally.

[Diane Pinkers]

You guys are inspiring me!  I’d like a wider pad, but at 5’4″ have no need for a 79 inch long pad.  I wonder how much weight I could lose, taking a STS Comfort Light Insulated L pad from 79 to 66 inches? Maybe not much, when I compare the weight of the S and the Regular, 6 inches difference of length changes the weight only by an ounce or so.

[Diane Pinkers]

Did you have to trim back the insulation any, in order to make the edges reach?

[Bob Moulder]

Diane, the answer to that, technically, is ‘No’, because it matters only that the two surfaces to be joined have to be clean with nothing between them when heat is applied.

However, practically it is much easier to do this if the insulation is cut back an inch or so to keep it out of the way while re-sealing.

[Steve Collins]

I know this is an old thread but just checking in to see how the S2S mod has held up.  I have been wanting to do this for quite some time to one of my pads, love the wide width but not the length of unneeded extra length.

Thanks!

[Scott N]

Also wondering if you had any issues rolling and stowing after the mod. I use this pad in the short, and one of the things I love about it is how tiny I can roll it up.

[Adam Kilpatrick]

Steve and Scott, sorry about the slow response!

No issue with this modified S2S pad. My seams are still like new. I doubt that will ever change.

No issues at all with rolling it up after the mod, if anything its easier just because it is shorter. The material is very flexible, both the external fabric and the insulation.

I’ve switched to using an S2S ultralight pillow as my Big Sky ones developed annoying leaks. I’m toying with the idea of doing a mod though to allow me to attach the pillow to the pad, probably with just a small 3gram carabiner, so that it doesn’t shift in the night. But then the other day I finally tried it with my bug bivy and the bivy has a nice effect of stopping the pillow from shooting off in the night. So I might not need to. Maybe I’ll mod the pillow to make it smaller in the future…

 

 

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