11.4 oz 78x20x2.5″ Sleeping pad :)

[Bradley Danyluk]

Bike pumps are designed for low volume, high pressure. Air mats are very high volume, very low pressure. It would take forever and be a lot of effort.

[>> Bender <<]

Bradley 45-46" is the widest I can go by making the baffles go horizontal. Otherwise the widest would be 40-41" with baffles going vertical. I can do goose down or Climashild XP insulation.

[Nick K]

I'm still very interested in this project and was wondering how the how-to guide is coming along. The less mistakes I make the first time around, the better.

Thanks!

Nick

[Brian Wiehn]

I came across this thread on Hammock Forums and being one that likes to make a lot of my own gear and cut down weight as much as possible I found this thread very intriguing. Wanting to try this project out myself, I went to questoutfitters.com and they have 2 types of heat sealable fabric that they sell and both are $6.99 a yard. The first is 200 denier Heat sealable Oxford, and the other is a 70 denier Heat Sealable Taffeta. Both are 100% nylon. I have not purchased either of these but I have made many purchases over the last year from Quest and they are always top notch to deal with and their shipping prices are some of the lowest I have bought from.

[dale stuart]

As I recall this product is a 30 denier, so is much lighter than 70 or 200 but will be more fragile.
For the DAM you may look at Skunk Works pages. For his DAM, he made silk tubes filled with down. Using this technique you would make 1) several silk tubes filled with down, then make the air mattress (3 sides sealed) insert the silk/down tubes then finish seal the 4th side.
-Dale

[obx hiker]

There,s a post on the blog somewhere about a homemade or rather home-tweaked ultra-lite pump. Here it is:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=27928

[Frank Deland]

JB Weld is found in auto supply stores. It can withstand high heat, so is used in engine part repairs. It must it be a kin of epoxy, since it is fsold in a two tube kit with the ingredients then mixed to harden.

(used in homemade alcohol stoves)

[Bob Gross]

There are a few different types of J B Weld. You want to make sure you have the kind you expect.

–B.G.–

[Corey Miller]

I have never joined a forum such as this where I have been so absolutly blown away from the innovation!

Been here 2 weeks and already have 120+ bookmarks… which is quite a mess and I've been saving pictures along with the url as names… so I can refference back..

Totally blown away by everyone here!

[Frank Deland]

Another alternative to the iron and not as hot as a soldering iron would be a ski/snowboard repair gun or pistol used for melting and distributing "ptex" into a gouge in the base of a ski or snowboard. Some models are around $40.
http://www.slidewright.com/proddetail.php?prod=K106C&cat=52

[David Franzen]

I have been thinking about the downs in the air mattress:
In order to prevent the down from leaving your mattress when you deflate it, you'd want to install some kind of a 'net' on the inside of the valve. probably an inch or two away from the valve in order to increase the net’s surface area.
However, when storing the mat at home inbetween your trips, the air tight mattress is not a good place to keep the downs. It is too constricted and they have no way to ‘breath’ which downs should. Thus, i think it is best to somehow make that net mentioned above removable. In this way you could remove the net and then let let all the down out and keep them in a better siuted place inbetween backpacking trips. Letting them out should be fairly easy, just by deflating it most of them should exit. And if you deflate the mat’s air along with the downs into a proper nylon bag right away, it should not be too messy (i.e. not loosing too many downs). Also, you’d want to take a very tight woven nylon bag for this with avery small opening preferably one that you can ‘attach’ to the valve of your mat. In this way, when you want your downs back in your mat, you can just attach the storing bag’s valve to the deflated mat’s valve, open the valves and pump up the valve with the storing bag. (in order to make this work, the nylon of the storing bag needs to be woven tightly enough to use it as a pumping bag, yet breathable, else you had gained nothing.)

The Problem is i’m not too sure as how to install that removable net in the mattresses valve. What are you guys thinking about this?

Another concern: has anyone tested the mat with a radiation barrier (solar blankt or space blanket) in order to increase the mat’s r-value (clo)? In the NB fugu jacket this seems to be working quite well. And is thermarest’s neoair not having one of those radiation barriers as well?

David

[Rog Tallbloke]

Bender: what sort of weight would a 72" mummy pad with climashield XP come in at? Would it be as warm as a Thermarest prolite 4?

[>> Bender <<]

Rog with some of the new material I have a 72x20x3.5" mummy with Climashild XP can be as little as 12oz. Compared to a Prolite this would be 3.5x thicker with a slightly higher R value.

David I have already made numerous down air mats so I have learned quite a bit. Any method to keep the down perfectly in place or have it removable kills the weight savings. The down is not going to be highly compressed unless the R value were very high. Even when down is compressed it retains a great deal of its effectiveness.

[Richard Seifert]

Bender i first have to say i love the work you have done.

I have a question regarding the baffles. How do you make the baffles and what material do you use?

I am currently working a a few DIY projects and this was one thing that i was trying to figure out.

[Kevin Beeden]

> What are you guys thinking about this?

I'm thinking that it's not a practical proposition. I really can't see that the down would:

a) come out entirely through the valve
b) be able to be blown back in again

I think the valve opening would simply be too small. then there's the issue of re-distributing the down, even if you can blow it back in.

What you might do is add a second valve, and blow a gentle, continuous stream of air through the mat in order to remove any moisture that has collected in the down, whilst not moving the down around within the mat. If you warmed the mat whilst doing it, it would assist in the evaporation and elimination of the mositure.

I have an Insul-Max MaxThermo, and wish it had a second valve so I could do this; you can see moisture in the thing when you deflate it fully. One day I'll build a cycling inflate/deflate pump to try to address this…

[John Vance]

I received my pad from Bender yesterday and have to say I am impressed. The seams and sealing is very consistent, straight, and even. My custom pad used the standard 70d fabric and is 24" wide, 60" long, and 3.5" thick with some 6 oz of down with the total weight coming in at 21.5 oz with an inflated size of 23" x 59". This is replacing both my short and regular length exped downmat 7's that weighed 20.4 oz and 28.5 oz respectively (without the pump-sacks). I decided on this length based loosely on the measurement from the floor to the top of my shoulders and will put my pack under my head to help elevate my stuff sack pillow. I wanted a wider pad and expect the extra width this new pad provides to help with cutting down on drafts during quilt use, as I tend to toss and turn throughout the night. I do not strap my quilt to the pad but often use some elastic straps that I made to keep the quilt wrapped around me while still allowing for all my moving around. This width also allows for laying on my back while having my elbows and arms stay on the pad without having to clasp my hands across my abdomen. For reference I am 5' 9" and 170lbs with a shoulder girth of 51"

The fabric had a much softer hand than I expected and is certainly much lighter than the fabric on the other insulated pads I have used in the past. It doesn't seem to be any more noisy than other mattresses and certainly less than a neo-air. I deliberated over the 30d fabric but glad I went with the heavier 70d. He also has a 200d for those that tend to be harder on gear or use little to no ground cloth under them. The 200d is probably more like the fabric used on the exped downmats which are 170d or 190d as I recall. The pad seems to be quite a bit more "bouncey" than my previous pads but I don't think it will be a problem. Some of this is due to the fact that the pad is 3.5" vs the 2.8" of the exped mats. Moreover, the Kookabay pad even though it is 4" wider uses 2 fewer chambers across the width. I am not sure what the baffles are made from but in earlier posts Bender had mentioned that he had been experimenting with sewing mesh to strips of nylon and then heat sealing the strips to the top and bottom. If mesh netting, that could also contribute to a little more stretch or bounce. Based on the way the pad inflated it appeared that air moved across the chambers as much as it did from end to end, suggesting that perhaps mesh netting had been used. When I tried to feel through the fabric to help determine the material being used, I could not tell if there was a seam or not. If I were to construct one myself I would use the 30d nylon for the baffles not wanting to field test the long term durability and reliability of the netting or the sewn connection between the two, while still minimizing weight. Perhaps Bender can shed some light on this.

The pad inflated great but I must admit that I had a difficult time getting it to deflate. The valve used appears to be a nylon material and is a simple barbed hose fitting with some mesh netting stretched across the internal end to keep down from escaping and a screw on cap with a gasket that has been attached with silicone. The down pods act as a very effective one way valve against the mesh and with the pad fully inflated and the cap removed, it took nearly ten minutes to deflate and I had to keep folding while laying on the mat. I did find that if I put my finger in the valve and moved it around, it seemed as though I could get a faster flow. A plus to the slow deflating is that the down should stay better put in the chambers and not want to move toward the valve end. There is no mechanism for keeping the down from migrating from one chamber to another which will happen over time and there isn't enough down in the mat to keep it in place based on friction alone as is the case in a slightly overfilled sleeping bag chamber. If the baffles are in fact a mesh material, they will help hold some of the down in place. A thin strip of open cell foam could be placed at either end and attached via the heat sealable cover. Not only would this keep the down from migrating, but it would eliminate the slow deflation by not allowing the down the clog the air valve. This would come at the expense of some weight and bulk but it wouldn't be more than an ounce. At the very least, if a small block of foam could be cut into a triangular shape and placed in the corner where the valve is located, it would significantly reduce the deflation time and add negligible weight or bulk and allow for better integration of the more typical pad valve that would integrate with all the pump sacks available on the market. If he goes into full time production I am certain he could get a very competitive price on the valves. The only other finishing touch would be to radius cut the corners slightly but it isn't a big deal – just a nice touch on a great pad. I had a Stephenson's DAM many years ago and this pad is a much more commercialized product.

Sorry about the long post but I know there are many fence sitters out there wanting more info. All in all a very impressive pad from the ever growing cottage industry. I will be out this weekend testing the new pad and a new 14oz quilt. It may seem a bit odd to be combining a 14oz quilt with a 21.5 oz pad but it makes perfect sense to me. ;-)

[>> Bender <<]

A few have asked about baffle materials for the insulated pads. Currently I use the same baffle material as what is used for the shell. I have been experimenting with using 30d baffles and 70d for the shell to get the best of both worlds. For a full size pad this saves roughly 1oz. I need to do some more testing before all are made this way. Deflation gets easier when you find a way that works well for you. When I wake up in the morning I pull the plug and let the air mat deflate. With any air mat insulated or non; rolling it up once quickly to get most of the air out is a good idea. This will allow you to make the final roll up much smaller. I must say I have a bit more experience in this area than most. I do several a day and it does get much quicker with practice!

[John Vance]

Thanks for the info Ben. I have found over the years that if I release the valve to let out the air when it's time to get up, I have a hard time laying there for long on the cold hard ground. With your new pad I now have a bit of a "snooze" alarm which becomes more appreciated every year.

[>> Bender <<]

John that is my point exactly. When I deflate and end up on the ground it finally gets me out of bed. Now if I could only hook my alarm clock to the valve the wake up system would be fool proof!

[Richard Seifert]

How do you make the i beams? Do you use 2 pieces together or just one piece?

Also i found this valve that might be a substitute:
http://www.scubagoo.com/index.php?dispatch=products.view&product_id=30522
http://www.halkeyroberts.com/products/inflation/oral-tube-tube-end-relief-valves/800rol-oral-inflation-valve.aspx

[P ritch]

Awesome work, Bender! Have you sourced any more 30d material?

Also, have you pursued the UL pump idea?

[>> Bender <<]

Richard each I beam is its own piece. The valves look quite heavy to me.

P ritch yes I have and its averaging 7g a yard less than before! I have a working sub 1oz (with battery) pump but I need to get a bit more pressure out of it to work best.

[Nick K]

I would like to make an insulated sleeping pad using synthetic insulation (XP or combat). How do you recommend constructing the sleeping pad?

One idea is to sandwich the synthetic insulation between two pieces of shell material. In this case, how should the insulation be secured to the shell material? Or, do you recommend a different approach?

Regarding the valve, what is your preferred product so far and method for securing it in place?

Thank you,

Nick

[Nick K]

BUMP !

[sheila o]

Nick,
Maybe send Bender a PM(personal message)?

[Author]

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