Adding valve to cut off inflatable pad

[u/davidhateshiking]

So I cut up a seatosummit xr large pad in order to make a 150cm long and wide pad and was thinking about making another small pad out of the spare piece I cut off. Has anyone done something like this?

I found two options of valves I might buy for this.

1. Similar to the old Thermarest style valve. Would be great because the whole length of the pad remains unobstructed by the valve and you can reach it easily to fine tune the amount of air during the night.

2. Round style. Not ideal because I’d like on that let’s out the air on its own once opened. If you know of something like that available in Germany let me know.

Thanks for any advice and suggestions.

[u/uznme]

I suggest also adding one of the farty tube things from a whoopie cushion, because funni.

[u/niwo6]

How much weight did you save by cutting it?

[u/davidhateshiking → u/niwo6]

Forgot to measure it before cutting it up and threw away the small cut offs but according to the internet it weighs 530g and now it weighs 353g. So pretty decent weight savings and noticeably less bulky.

150cm seems to be the no compromise length for me at 171cm. I can fully sleep on it when on my side or use my sit pad and/or pack underneath the calves. Haven’t tested it out on the trail yet but have used the discontinued 120cm x-lite in the past and it worked pretty well aside from being not wide enough for my liking. That’s why I went the diy route.

[u/niwo6 → u/davidhateshiking]

Nice! I just cut my foam pad.
Did you glue or weld this where u cut it? Is there a tutorial for this?

[u/davidhateshiking → u/niwo6]

I wish I could use foam all the time. So much simpler but I often camp on mountain tops etc. where the only halfway decent spot for sleeping might have a rock poking out and it’s nice to be able to float over top of that instead of having to relocate.

Sealing it actually is super simple. There are some videos on YouTube but essentially you cut back the inner Mylar layer so top and bottom lay directly on top of each other and use a clothes iron to get a thermal bond of the two layers. I used a sheet of baking paper so nothing gets stuck on the iron and then slowly increased the temperature until the fabric started bonding. I should have used a guide to make the seam more consistent but it totally worked free hand and I only had to redo one tiny spot (definitely thoroughly test it before taking it on a trip). All in all was done in less than an hour and now I’d probably only need ~20 minutes.

[u/npipe]

The side-on valves are significantly harder to seal in my opinion, especially for a one off project. The curve, plus the fact that you have to match both fabric layers to it, makes it kind of tough. That said, even if its not perfectly airtight after ironing, I'm sure you could get it sealed with some glue.

This style of round valve is pretty nice: https://www.amazon.de/UtySty-Inflatable-Replacement-Airplane-Footrest/dp/B0DX234L99/704-5802689-9461526

[u/davidhateshiking → u/npipe]

Hey nice to hear it from someone with your experience. I kind of ignored your advice though and ordered one of those side-on valves lol. I have an old busted self inflating pad that I can try to seal first and if I find it too annoying I’ll definitely order the one you linked. Is it the one you use on your pads?

Also good luck with getting all the orders fulfilled after extra shouted you out. I bet you have your work cut out for you in the foreseeable future ;)

[u/npipe → u/davidhateshiking]

Ha! The advantage is now you don't have to mess with cutting a hole for the other style of valve.

Those are the ones I'm currently using, but Im going to swap to something lower profile soon

[u/davidhateshiking → u/npipe]

I guess I’ll find out if I made the right call.

I might have to come back to you for that lower profile valve after all.

[u/nbphotography87]

I just shortened my Uberlite pad after the top 5 baffles delaminated in the head area by the valve.

so I couldn’t reuse the original valve.

I went with the round style valve as the installation process was much more straightforward.

[u/marieke333]

Adventurexpert has this one: https://www.adventurexpert.com/product/tpu-valve/ A bit large though. And Extremtextil has one that is lighter and looks smaller. I haven't tried it: https://www.extremtextil.de/en/tpu-valve-two-way-weldable/73178

[u/IFigureditout567 → u/marieke333]

The Adventurexpert one you linked happens to fit with Nemo pumpsacks and pump adaptors.

[u/davidhateshiking → u/[deleted]]

There is dozens of us out there - I tell ya dozens.

You can find tutorials on YouTube. It’s essentially the same process they use in the manufacturing process to seal them - just less professional.

So far have taken a three hour nap on it and it held air perfectly. Will probably do an overnighter soon.

[u/fruit-bear → u/davidhateshiking]

3 hour nap! That’s verging on a full nights sleep around here!

[u/davidhateshiking → u/fruit-bear]

Well I only actually spend about an hour of that sleeping. I just wanted to make sure the seam is actually airtight so I spend my afternoon after work on it and ended up falling asleep lol.

[u/davidhateshiking → u/[deleted]]

Did you send it back to Thermarest? They replaced my x-therm after it started developing pinholes along the baffles - no questions asked. Might be worth a shot to send them an email before you cut it up.

You won’t be able to put any thermal insulation inside because of the shape of the insulation inside. It is suspended in triangles from top to bottom so no way to push anything through.

Torso length pads are more of a summer thing for me anyways so you might be fine with the lower r-value.

[u/davidhateshiking → u/[deleted]]

They replied after a day or to for me so fingers crossed they’ll get back to you.

If you end up shortening it I can definitely recommend to do it in steps so you can get some practice. My second or third seam was much neater than the first. Summer is where the short pads really shine in my opinion. Even when the r-value is lacking it’s mostly about comfort anyways less about insulating from the ground.

[u/davidhateshiking → u/[deleted]]

Good luck with the warranty process. Good to hear that they didn’t ignore you this time.

I did shorten an uninsulated pad with long baffles in order to make an inflatable bottom for my pack raft. With the pad you have you’d have to cut it open the entire length and count out the insulation and then reseal it. Sounds like too much work to me but should be the same process as shortening the length. Tbh I’d probably sell it on the used market and buy something more up your alley.

[u/Electrical_Emu1875]

Thank you for this post!!! I have a pad that otherwise would have been garbage but I am now looking to do something like this. Was installing the valve fairly straightforward? I am a little suspicious of the Amazon valves and am reasonably sure they won’t arrive with any installation instructions…

[u/davidhateshiking → u/Electrical_Emu1875]

Well you have misunderstood the post slightly. I cut up a perfectly good pad just so I could get a shorter pad. I’m trying to use the part I cut off as some kind of big sit pad/ emergency pad for long day hikes. However u/npipe makes their own pads and has posted about it on here before. I’ll let you know how the process worked for me I once the valve I ordered arrives and I get some time to attempt to attach it to the spare fabric.

[u/Electrical_Emu1875 → u/davidhateshiking]

I’m simply sharing that I plan to do something similar with a pad I have, which would involve both cutting a pad down and installing a new valve. What do you believe I have misunderstood?

The new information is that you haven’t completed the valve installation yet. I really appreciate you linking to the other user - I’ll check that out and I also look forward to your updates once your project is progressed.

[u/davidhateshiking → u/Electrical_Emu1875]

My bad I had just woken up. I’ll make a new post when/if I manage to install a valve successfully. It’ll take some time to arrive from china and I’ll be busy the next few weeks but I’m hoping to do it soon.

[u/Electrical_Emu1875 → u/davidhateshiking]

I’m really looking forward to it! I might actually get to mine first and will post if I have any learnings as I go

[u/davidhateshiking → u/Electrical_Emu1875]

Good luck and ping me when you end up posting about it :)

[u/Electrical_Emu1875 → u/davidhateshiking]

Yo! First attempt complete. The outcome:

• edge seal looks perfect and I think is working well
  
• valve seal is a mess and is leaking. I’m not sure how to get a better seal. I tested the temps then sealed it with an iron and am thinking I need to order the heat sealing iron instead to allow more agility. I also made a wooden jig to press against, but it’s still bad in spots :-(

[u/davidhateshiking → u/Electrical_Emu1875]

Some good news and some bad news. I hope you’ll get the valve to seal properly. How bad is it leaking around the valve? Might be able to use some type of glue to get the leaks plugged up.

The heat sealing iron might be worth it if you end up doing it more than once. I’ve seen them pretty cheap on AliExpress last time I checked.

[u/Electrical_Emu1875 → u/davidhateshiking]

It’s pretty bad and i don’t think it’s salvageable. My plan is to cut that part off, seal it as an outer edge, and make a second valve attempt with a new valve elsewhere on the pad. The gorgeous edge seal gives me hope…clearly it works, it’s just the complexity of the area around the valve that got me. If the next one looks cleaner but leaks I’ll definitely try to add glue.

And I ordered a heat sealing iron. I’ll give it a try. If I hate it, I can always return it!

Onward!