Homemade sleeping mat

In my on-going quest to make everything myself, I decided to make a sleeping mat. This is suppose to be similar to a downmat 9 or a warmlite DAM, or even a BA Q-core (although a q-core has synthetic insulation). Now, I haven't finished it yet. I still need to add the insulation (wanted to try it out before throwing down a lot of money on down). I made it a little long so that I can cut it open and add the insulation latter. Here are some pictures of it. When I finish with the insulation, I will put together a video, but for now.......

This is during the construction. I was cutting out the baffles and taping them, prior to heat sealing.


Here it is all sealed up.


And here is the valve I used. It is a kitevalve I bought online.


The dimensions are about 25" wide when blown up, about 75" long (it will be around 72" when I finish it), and 4 inches thick. I am guessing, based on the Exped 9 LW that I will need to add betwen 10 and 11 oz of down. I still need to sleep on it to test it for leaks.

As for how did I heat seal it,.......well.....I cheated. I "borrowed" an impulse heat sealer from work. It is a real nice one that heats both sides.

how are you going to inflate/deflate without losing down? or, how to inflate it without blowing all the moisture in your breath into the down and causing loss of loft and growth of micro-organisms/mold?

Nice work, so far.... looks somewhat like a q core.

Actually looks pretty darn good ... ditto what Lori said. And I'm a little confused as to how you will put the down in evenly without putting at least 5 cuts in it...or is that what you have in mind? You are starting to look like another potential entry into the cottage world of gear making.

Wow!

That's impressive. I'm looking forward to learning more about this!

Great questions....I am still working them all out. I plan to use a pump, like the instaflator . Since I plan to use down, then I have to have a pump.
I also plan to put down in net tubes and insert the tubes into the mat. This should keep the down from moving around. I also plan to put a foam cover over the valve.

I copied the q-core design. I thought it might drop some weight by using half the baffle material. Hopefully it also adds comfort (based on your q-core review).

All I see are the mistakes. I even made a really big one that I was able to fix. I need to make at least another 3-4 before I can realistically start selling them. I need to get my construction process more streamlined and exact. But I am still debating on if I want to do it. Kookabay demonstrated that there is a need for another cottage/custom manufacturer for sleeping pads.

As for the down insertion. I plan to cut the top and bottom seam (making it a big tube with baffles). Then insert mesh tubes of down. I made the mat a little long to accommodate this. Of course, sitting here thinking, I wonder if I even need tubes. Can I just put in the down loose. Of course I would have to protect the valve from clogging. But, because the baffles are open, down would be able to move between them easily. Maybe all it needs is to blow up the pad, then shake the down around to evenly distribute it. As you can see, I am still thinking about it.

Wow. So you are serious... If you haven't already figured this out, I shape and make surfboards. Making the whole board, the first time, you learn a LOT. But you learn a little bit every time you make one. Same for every thing else I make (I've completely redone our kitchen from the studs out). Get a process draft out of the first one, and continue to modify it as you make more. PROCESS is key to reproducibility; and if you are selling them that is what you are aiming for. Sorry, you probably already know this...Off soapbox.

Have you figured out how to calculate/estimate R-value yet? With the mesh tubes, insertion would be easy by pulling a line through first. But you would have cold spots between each "tube". Might be fine for a first pass though. The loose down sounds like a potential nightmare to me, given the nature of your baffle system. I suppose you could put mesh around your valve, but the down will still have a tendency to drift around. Probably already thought about this but might be interesting to get your hands on a "destroyed" down mat and cut it up. A little reverse engineering if you will.

I'm also thinking mesh baffles ...

Yeah, process is key. If I can't make these in a short amount of time, then I would have to sell them at a price that no one will buy them. Time is money, when you are making something for profit.
I do plan to make a few more. I plan to make one for my dad, and my wife. I also have a few friends who want one....but they might balk when I tell them the raw material cost.
I have been able to source the materials from original manufacturers. That will cut my material costs, but I would have to make a large initial purchase.

Buying in bulk helps a lot...if you have a market. I have bolts of weird cloth (impact, and others) stashed in my garage that are hard to work with but produce stellar results. I may have these for 12 to 18 months before I need to re-purchase. On the plus side, NOTHING made from petroleum that I buy will decrease in cost over the next few years. If the past is any clue to the present with this stuff, the price only goes up or stays stable.

I wonder if you could make a tube from two pieces of plastic material where the bottom half is reflective (shiny side up) and top half is net.

I think I read the Neoair mats use a reflective material, similar to a shiny "space blanket", inside their mat that is formed like a honeycomb. They also use a (somewhat) reflective bottom surface on them.

I was thinking about adding a reflective layer. I decided to try it on another version. I was thinking of just cutting a big flat piece then slitting it with the slits matching the baffles. Then just feeding the baffles through the slits. The down tubes would sit on top. I can still do it by cutting it in strips and having the down sit on top. The down tubes would prevent the reflective sheet from moving around too much.

Pretty impressive! Good job.

Hey finallyME. What I was trying to say in my previous posts (in the classic skcreidc thread drift)is that my making surfboards(for 18 years and 15000 boards now) and you making these pads is not so different. First of all, both processes use petroleum based products in amounts that barely constitute a blip on the petrochemical companies radar. So raw material prices go up but they don't come down (as the price of crude oil does). You can kind of see this in gasoline; prices go up faster than they come down. And second, how you make your 10th pad will be very different from your 100th pad, and so on with your 1000th pad. So don't be too quick to toss in the towel after 6 pads. After 10 to 20 pads, you will actually start to know what you are doing (in the production/manufacturing sense). Anyway, you will sure know pads after this no matter what. So have fun with it and good luck.

Thanks for the encouragement. Hopefully I will be able to see if you are right or not, with my 1000th pad.

No, I haven't yet. I have seen how others do it, sort of. Most people do it in regards to sleeping bags. I am wondering if it applies to pads as well. I was thinking of measuring it instead. Put a heat source on one side, with a thermocouple on either side to measure temperature. There is a good BPL article about it, but I don't have a membership.

Fantastic! So, the baffles are only taped and not heat sealed? What type of tape did you use?

And, for those who don't have access to fancy heat sealing machines, I had success making quick and dirty rain pants for my oldest son out of a trash bag (polyethylene) by sandwiching it between two pieces of paper and running over the seams with an iron on low heat. I think I had it about 1/4 to 1/3 the way up, and even that was really a bit too hot, but it worked.

In reply to this:
I believe the reflective surfaces mostly depend on having air space next to them to work their best, so having down fill packed next to it may reduce their efficacy. It might still be worth it, IDK. You'd have to build two versions that are identical except that one would have the reflective surface and the other would not and compare their warmth.

I didn't use any tape. All heat seal.