D.A.M. vs Underquilt - Why Choose?
- Ok, I will be the first to admit that I am not an expert on DAM's as
I had not considered one, and have been working on my own design for
an underquilt while reading all the posts. It is very likely then
that I missed something along the way, however, I do remember someone
made a 14 oz DAM at home, and all the pictures I can find on here or
elsewhere on the web look like all a DAM is a baffled sheet that is
air tight right?
Here's my thought then, why can't an underquilt have some or all of
it's baffles made air tight. When you are hanging, it can be slung
underneath and the valves left open so that it conforms just like any
other underquilt. When conditions force you to go to ground, then
simply inflate the baffles, close the valves, and voila, instant
ground pad. If not all of the quilt inflated, the soft edge baffles
could be made with velcro to attach to an overquilt and it would
function as a sleeping bag, with the edges overlapping and preventing
drafts. I was all set to order my material from Thru-hiker when this
idea occured. I realize that this would be heavier than a non-
inflatable underquilt, but as my design seemed like it was going to
be 16-17 oz, I would not be opposed to going up to or slightly over
the weight of a Jacks nest if I got even greater flexability out of
What does anyone think? Would this work? Am I nuts for trying? If
you think so, what does one make the air tight chambers out of? The
professionally made DAMs seem to use some sort of laminated Poly,
where do you get that or is there a better alternative out there?
Also, they say their seams are welded, but if you are talking about
poly/plastic/nylon, aren't those sorts of air tight seams really just
melted together? If so, then I should be able to assemble it with my
soldering iron or something a little cooler. Am I right about that,
or is there another way it must be done to work? Those of you that
did make DAM's, I am sorry but I don't remember how anyone made their
seams air tight. Thank you all for raeding, and thank you in advance
for the help.
- Dylan and others, On my Home-Made DAM (My pictures
in the Albums) the Poly Tubing comes in a long
seamless tube on a roll. You cut it what ever length
you want your DAM to be and with a "Heat Seal" thing
you double seal one end. You make a sleeve wide
enough for however many tube you want and as long as
you want your DAM to be.
The open end of the Poly Tube is used to slide your
baffles with the Down into it.
As a side note you can remove the Down baffles to dry
out if necessary or to leave out for summer use. You
can also make another set of Down baffles for
different temperatures. My DAM is made for "0" F
Once the Down baffles are in the Poly Tubes you can
blow them up with air and roll the end closed. I use
a small light balloon pump then clamp the ends closed.
You sleep on your DAM and in the morning or when ever
you remove the clamp, let the air out and pack it all
One of my Poly Tubes 5" wide (Flat) 78"+ long and with
a baffle containing 1oz of Down weights 1.5oz. My
latest DAM has 7 Poly Tubes (10.5oz) plus the weight
of the sleeve. Add the weight of your sleeve (3 to
4oz) and you get a DAM that gives you 3.5" loft about
30" wide and 78" long well under 16oz. My new one may
be about 14oz total. Cost - 7oz of 800+ Down (about
$56), 7 (5" Flat) Poly Tubes 85" long (less than $10),
Sleeve material (5 yards at ??) and a weight of (for
me) .5 to 1 oz a sq yard. My sleeve weight can be as
low as 2.4oz. for my new one.
This is a total weight of about 14oz and a cost of
about $110(+/-) a little if you go with some really
high cost material or a lot cheaper if you use some
cheap stuff from Wal Mart. My first one was made from
some $1 a yard (2oz a sq yard) stuff from Wal Mart.
In contrast my Warmlite DAM cost $165 and weighs about
27oz counting the blow up bag.
The hidden advantage to my DAM is that I can use the
Down baffles from the Poly Tubes in something else
during the day.
Bill in Texas
--- Dylan <hum469@...> wrote:
> Ok, I will be the first to admit that I am not an__________________________________
> expert on DAM's as
> I had not considered one, and have been working on
> my own design for
> an underquilt while reading all the posts. It is
> very likely then
> that I missed something along the way, however, I do
> remember someone
> made a 14 oz DAM at home, and all the pictures I can
> find on here or
> elsewhere on the web look like all a DAM is a
> baffled sheet that is
> air tight right?
> Here's my thought then, why can't an underquilt have
> some or all of
> it's baffles made air tight. When you are hanging,
> it can be slung
> underneath and the valves left open so that it
> conforms just like any
> other underquilt. When conditions force you to go
> to ground, then
> simply inflate the baffles, close the valves, and
> voila, instant
> ground pad. If not all of the quilt inflated, the
> soft edge baffles
> could be made with velcro to attach to an overquilt
> and it would
> function as a sleeping bag, with the edges
> overlapping and preventing
> drafts. I was all set to order my material from
> Thru-hiker when this
> idea occured. I realize that this would be heavier
> than a non-
> inflatable underquilt, but as my design seemed like
> it was going to
> be 16-17 oz, I would not be opposed to going up to
> or slightly over
> the weight of a Jacks nest if I got even greater
> flexability out of
> What does anyone think? Would this work? Am I nuts
> for trying? If
> you think so, what does one make the air tight
> chambers out of? The
> professionally made DAMs seem to use some sort of
> laminated Poly,
> where do you get that or is there a better
> alternative out there?
> Also, they say their seams are welded, but if you
> are talking about
> poly/plastic/nylon, aren't those sorts of air tight
> seams really just
> melted together? If so, then I should be able to
> assemble it with my
> soldering iron or something a little cooler. Am I
> right about that,
> or is there another way it must be done to work?
> Those of you that
> did make DAM's, I am sorry but I don't remember how
> anyone made their
> seams air tight. Thank you all for raeding, and
> thank you in advance
> for the help.
Yahoo! Mail - PC Magazine Editors' Choice 2005
- Wow, only one reply. Either my idea isn't as exciting as it seemed
when I came up with it, or a lot of people are luckier than me (out
camping instead of here reading the board to avoid work)!
Thank you Bill for your reply though. I had seen your DAM in the
past, and I was thinking I might employ something similar. The only
issue I have to deal with though is the way in which you inflate
yours. Since mine will be embedded in an underquilt, I would not be
able to clamp the ends of each baffle. Also, with an unsealed end
when I am using it as a quilt, I would have the added problem of the
down getting out when I am using it soft. What I am thinking is that
all my baffles will have to be connected in som way, and inflated
through one or two valves, much like the professionally made DAMs.
Now I know I can heat seal both ends, but I am not sure how I would
attach some sort of cross tube or valve assembly that would still be
air tight and not terribly heavy.
I know this is going to be a lot more work to solve than either the
underquilt or a normal DAM would be on their own, however, I would
love to be able to have the flexability without the worry of choosing
which to take before I even get where I am going. I would simply
stick to the underquilt because I know I prefer the comfort of them
over the pad or DAM methods. The trouble is I live in a state that
is half desert, and I like to see what is over the next hill. I very
often have no idea what to expect untill I get there, and everything
I have is all about the flexability. To that end then, while I can
often hang my hammock even where there are no trees, sometimes I am
forced to ground. When that happens, I must have something else.
Therefor, I am willing to take on the extra difficulty of building an
inflatable quilt as it were. In fact, I think I will add the
following to the lexicon; IDUQ - inflatable down under-quilt. That
is my mission at this time, if anyone else has any thoughts or ideas,
please feel free to jump on it. I will need all the help I can get!
P.S. Bill, where did you get the poly-tube from? I am sure that is
answered somewhere on previous messages, but somehow I am missing it
when I search past posts.
- --- In email@example.com, "Dylan" <hum469@y...> wrote:
> Wow, only one reply. Either my idea isn't as exciting as it seemedI think it's a great idea to test, but not many people have experience
> when I came up with it
making inflatable mattresses so it's hard to offer advice!
I'm curious how to join the tubes together to ensure loft BETWEEN the
tubes. For example, a 2" sew-through quilt won't insulate as well as
a 2" baffled quilt because the thinnest point of loft is the sew-
through. Do you stagger the tubes? Or do you just deal with them
having a thin spot between them?
- That is a good point jwj32542, and it is thoughts like
that I am hoping to get, whether anyone has experience
or not. More people in the conversation means more
To address the question, at least in my case, I think
while the quilt is not inflated, it will act just like
any baffled quilt. When it is inflated, other DAMs
seem to be working for others without any insulation
between the tubes. Thinking about it, I think that
when weight is on it, the tubes smash a bit, deforming
from cylinders, to other less perfect shapes. Since
they are held tight together, I would bet that the
tops and bottoms of the cylinder curves expand out,
while the extreme edges (the only bit touching without
weight) stay the same since they are already tucked up
against one another. In this case then, I think that
the tubes take on a more square like cross section,
thereby insulating the space. At least that seems to
make the most sence since the tubes must deform some
way, and nobody with a DAM has reported any cold
strips so far.
Should it prove to be a problem however, I can add
insulation between the tubes too. The idea I have
basically is to have it constructed as similar to a
baffled quilt as I can, just with air tight baffles.
When used in quilt mode with no weight on it, it
should move and deform same as any other quilt. If it
does not, it would be possible to add down inbetween
the tubes. I really don't know though I suppose
untill I try. Anyone else have any thoughts or ideas?
Think it will work the way I imagine, or is there
something I am overlooking? I think I will order the
materials to start work some time in the next week or
so, I would like to have my plan completed. Thank you
all for your time.
Though I may die tomorrow, at least I can do it with the knowledge that once I did know true love -unknown
Yahoo! Mail - PC Magazine Editors' Choice 2005