Homemade tents

[Michael Ray]

I thought this should be split from the Cooking thread.

Al Geist wrote:
As seen in the picture at http://www.csm.ornl.gov/~geist/Philmont
We only took one of the MYOG tents. The boys used more traditional shelters such as Sierra Design Lightening.

A couple crew members talked about making light tents like mine for our Philmont trek, but they didn't get them finished before we had to leave. The 18 oz tent held up just fine. No problems or signs of wear and tear.

To learn more, go to the URL above. I just uploaded a new long article about the tent construction, the innovations that make it strong and tough (hint the Space Blanket does not carry the loads), and discussion of the different materials I considered in building it (from Cuben to polyethylene).

[Michael Ray]

Al,
Thanks for expanding your original document. It will prove quite helpful. I'm sure I'll have a bunch of questions still. :)

Does your 18 oz figure include all the cords, stakes and "floor" or just the main body? What kind of size does it all pack down to?

Was the duct tape used clear for purely aesthetic reasons?

What type of condensation issues did you have since it's barely vented while raining?

[George Geist]

> Does your 18 oz figure include all the cords, stakes and
> "floor" or just the main body?

18oz for main body and all cordage
4oz for the 9'x9' sheet used for the disposable floor
1oz for 22 wire stakes (plenty and then some)
1oz for dry sack that I put it all in

---

24oz Total

> What kind of size does it all pack down to?

If you want to get crazy compact. I used to pack the
mylar tent body, cordage, and stakes in a quart ziplock bag!
I packed the floor into a second quart ziplock.
After a few trips I came to my senses and realized I was
spending more time getting the tent into the ziplock than
it took to take the tent down. So I got "less crazy"
and just put the stakes, cordage, floor, and body all in
a single small drysack in the order shown in the article.
The dry sack is 11"x7"x3" and I can squeeze the air out
AFTER putting everything into the sack to make it smaller.
Much faster, easier to pack up the tent this way.

> Was the duct tape used clear for purely aesthetic reasons?

No. You want to use "Scotch Transparent Duct Tape"
for the following reasons:
– The clear duct tape is 6X more UV resistant, i.e. it will
last six times longer than gray tape when exposed to the
sun's rays
– The gray tape has cloth reinforcement, which you can tear with your fingers.
The clear duct tape uses a mesh of plastic filaments (like strapping tape) which you can't tear. You have to cut the tape.
– The plastic reinforcements provide a stronger base for
sewing through. The sewing thread is going in and out around these plastic filaments
– The Scotch brand uses waterproof glue. I used some really
cheap tape on earlier prototypes and found that not all vendors
use waterproof glue.

And one other note. I used 1" wide strips of the tape in
building the tents. I cut the 2" wide duct tape roll in half
with an Exacto knife.

> What type of condensation issues did you have

I have had no condensation issues with the tent. I have been surprised, but I recently found out why in Mariah Walton's 2004 BPL article on Night Time Condensation on Tarp and Tent Fabrics, she first determined that tarp-walls cool below air temperature because they emit infrared radiation. She subsequently followed up this observation by testing several aluminized materials, such as a mylar blanket, that do not emit in the infrared. Theoretically this means that these materials do not cool below air temperature. In practice, she found there was no condensation on the mylar blanket during the twelve night testing period!

At Philmont the air is so dry that condensation was not an
issue. In Tennessee, where I'm from, humidity and rain are
the norm. In Tennessee I have avoided condensation issues by
– leaving the rain flaps rolled up when not raining provides huge cross-flow ventilation.
– overlap the rain flaps so that they are a couple inches apart so there is still good cross-flow ventilation but rain sheds off.
– heavy blowing rain. Button up the tent tight and keep saying to yourself "it is a lot dryer in here than out there"

[David Lutz]

Very interesting…

I'm new to all this stuff, but yesterday it occurred to me that I could make a small lightweight tent using an old-school Coughlin's tube tent as a starting point.

I would just need to work on the ends to keep the bugs and water out and let me and air in and I would be good to go.

What do you think?

I read the posts on Philmont and don't get how you closed up the ends of the tent you made before you attached waterproofing. Will you explain more?

Thanks!

[David Lutz]

Oh yeah….

Can I buy some of those fabrics and zippers from stores, or is it all mail-order?

I live in a built-up suburb with all the usual chain stores around.

[Michael Ray]

> I used 1" wide strips of the tape in building the tents. I cut the 2" wide duct tape roll in half with an Exacto knife.

Always looking to save weight. :) Interesting about the differences in the duct tape – I didn't know that. In your notebook sketches, you refer to both clear duct tape and "Scotch Ultimate tape". I don't find anything on the latter.

Also, did you butt the body blankets together or overlap? It appears the former based on your dims.

I'm also impressed your wire stakes can go into packed down tent sites like that. What approx gauge is your lawn mower cable?

I have 3 blankets on the way. Now I just need time to put something together!

[George Geist]

> Can I buy some of those fabrics and zippers from stores,
> or is it all mail-order?

Hi David,

I ended up getting the materials mail-order.
You may want to check out the MYOG forum (make your own gear)
here at BackpackingLight.com for possible sources.

Long, lightweight, #3 zippers were the hardest thing
I had to find. You need double-pull zippers, so you
have a handle to unzip the tent from the inside and
from the outside. I got mine from thru-hiker.com

[George Geist]

> Interesting about the differences in the duct tape – I didn't know that. In your notebook sketches, you refer to both clear duct tape and "Scotch Ultimate tape". I don't find anything on the latter.

Hi Michael,

Check out "Part 3" of Char-e-it construction at
http://www.csm.ornl.gov/~geist/Philmont
for pictures of both types of tape. I got both at Home Depot. Although I wrote "ultimate" tape in my notes, the official name is "Scotch Extreme Application Tape". The tape has stronger reinforcing filaments (130 lbs/in) and more aggressive glue compared to clear duct tape, but I don't know it's UV rating. It costs about $1 more a roll.

> did you butt the body blankets together or overlap

I butted the blankets. I stretched them out on an 8' 2×4 to remove the wrinkles from the edges before taping.
Here a couple tips I learned the hard way:
— The tape and blanket have electrostatic charges that attract each other. I would be getting the next few inches of tape lined up and the blanket would suddenly jump up the 1/4" to the tape hovering above.
— Once the duct tape touches the blanket, it can not be removed. So go slowly and carefully on the top seam.
I had to put in deliberate wrinkles in one spot to get everything lined up again after the blanket jumped up and touched the tape before it was aligned.

[todd]

Very interesting and useful designs! Thank you for sharing.

[David Lutz]

So…..any comments on using a Coughlan's tube tent as a starting point for a cheap, light tent?

[John S.]

The tube tent is polyethylene, not mirrored, and probably a little higher mil than a heatsheet?

[George Geist]

> I'm also impressed your wire stakes can go into packed down tent sites like that. What approx gauge?

Hi Michael,

I just measured the spring steel wire I used. It is 1/16" diameter. I think that translates to be 16 gauge.

The reason the wire stakes are easy to insert is because
the frontal area is so small. There is very little ground that has to be pushed out of the way. A small twist back and forth has always been enough to push in the wire stakes right up to the head. This was true at all our Philmont camp sites as well as on our shakedown hikes.

There is only one place I have had no luck getting in the stakes. It was in a packed gravel tent bed of an RV campsite. The message is don't do ultralight camping in RV campsites.

[George Geist]

> The tube tent is polyethylene, not mirrored, and probably a little higher mil than a heatsheet?

Hi John,

The Coghlan tube tent is 2.5 mil which is about 5 times thicker that a heatsheet and is not mirrored. The weight of the Coghlan tube tent is right at two pounds. Which is pretty heavy in the ultralight world.

[Michael Ray]

Indeed, the Coughlan's tube tent is 2.5 mil (wouldn't have thought it was THAT heavy though). The Heatsheets are 1 mil (at least what they use at race finishes – maybe the ones they make for AMK's use are different?). You won't have the design options available unless you cut the tube, but if all you want is an A-frame I don't see why you couldn't use one.

I'll be interested to see how the Heatsheets hold up over time. I note from the manufacturer's site: "The metal may begin to oxidize over time. That process can be accelerated if exposed to moisture for an extended period of time."

I assume that doesn't have any bearing on the integrity of the LDPE though. Just what little insulating value you may have gotten from the coating will decrease.

If you want to play a lot, you can buy a roll of 100 6'x4' sheets (in white rather than orange, too) for $87. You could make 25 8×12 tarps!

[todd]

Chair E it question:

You mention the Crazy Creek version as well: will it work just as well? Two concerns I have are 1) the weight is heavier & 2) the curve of the fabric at the seat appears to offer less of a 90degree angle so the dry bag may not sit as well on the "platform".

Thanks for your input.
Todd

[George Geist]

> You mention the Crazy Creek version as well: will it work just as well?

Hi Todd,

I have both chairs (Sling-light, Crazy Creek version). Crazy Creek made an exact copy (rippoff) of the Sling-light chair in every dimension including weight. The literature says the Crazy Creek headrest is a tiny bit lighter and the chair a tiny bit heavier. Together their total weight equals the total weight of the Sling-light on my scale.

So the short answer is "yes the Crazy Creek version will work just as well and save you a lot of money."

[Michael Ray]

A roll of 100 6'x4' Heatsheets is $87. Shipping is only FedEx so pretty steep. $20.11 from GA to IN. But $1.08/sheet isn't bad and they're a little more environment friendly being white with silver rather than orange.

http://heatsheets.net

I also ordered the rolls of tape Al recommended so I'll have plenty of stuff to experiment with when I get time. It seems both of those you ended up with are the best 3M has for this application. It doesn't appear the bi-directional filament tape (Extreme Application) has any special UV resistance so I think I'll cover it with the transparent duct tape. I also plan to do a weather test of samples this fall/winter to see how the tape and Heatsheet hold up to UV & cold.

[George Geist]

> It doesn't appear the bi-directional filament tape (Extreme Application) has any special UV resistance so I think I'll cover it with the transparent duct tape

Hi Michael,

Instead of covering the Extreme Application tape, I simply used the Extreme Application tape on the inside of the tent on the ridgeline so it would not be exposed to UV rays.
I used 1" wide strip of transparent duct tape to reinforce the edges of the tent body and stake tie-outs since this tape has good UV resistance (and is cheaper).

[Michael Ray]

Al,
I guess ALL the tape could be placed on the under (silver) side. In that case the polyethylene would likely break down before the tape on the other side of the AL. I couldn't find any info on whether they added any UV resistance to the LDPE, which normally is not all that good.

I hadn't thought the duct tape would be strong enough to prevent the sides from stretching over time from being pulled taut. I didn't find the clear duct tape in 1 or 2 inch widths. It seems it's 1-7/8" so if you cut the roll in half as you say, it's likely just 15/16" that you used along the edges. It's pretty impressive it doesn't stretch appreciably in over 7 feet.

[George Geist]

> I guess ALL the tape could be placed on the under (silver) side.

Hi Michael,

You can. I did this on my early mylar prototypes where I used stake loops (made from tape) rather than grommets. Since I was planning to use grommets on the Heatsheet version I folded the tape over the edge 1/2" on the inside and 1/2" on the outside. The inside and outside heads of grommet then goes through filaments on both sides.

You are correct the tape is not exactly 2" wide. It says 1.9" wide on the roll. I cut the roll down the middle so that each side had the same number of lengthwise filaments.

> It's pretty impressive it doesn't stretch appreciably in over 7 feet.

I haven't noticed any stretch, but realize that the design of the tent is such that the poles just pull the ridgeline tape tight each time it is pitched.

[Michael Ray]

> I did this on my early mylar prototypes where I used stake loops (made from tape) rather than grommets.

I was planning loops to stay away from grommets. It can't be pitched quite as close to the ground but that should aid in ventilation, too. Did you not like the loops? I was thinking of something like Scott Van Doeselaar did with his cuben tent.
. I thought the way he did his mesh would work, too.

> I haven't noticed any stretch, but realize that the design of the tent is such that the poles just pull the ridgeline tape tight each time it is pitched.

I was referring to the stretching as you pulled the corners taut (at roughly 45 degrees) to stake.

[George Geist]

> Did you not like the loops? I was thinking of something like Scott Van Doeselaar did with his cuben tent.

Having now tried both loops and grommets with Space Blanket material, I like the loops better. Scott did a nice job with his cuben tent. Since the maximum stress (and most likely point for a tear) is right at the edge of the material beside the loop, I ran a second 3" strip of tape along the edge to spread the stress. Here is how I made the loops on my Mylar tents.

To keep the loop from being sticky, I used a 1"x1" piece of tape stuck glue-to-glue in the center of the 3" strip of transparent duct tape forming the loop.

I run the wire stakes right through the loops into the ground. After about a year of use, I have not had any failures ie rips or tears at the stake loops (Knock on wood)

[Michael Ray]

> I run the wire stakes right through the loops into the ground.

The way you stated that makes it sound like you pierce through the tape material in the same spot each time. I had envisioned the stake would go thru the loop created in the tape (where the 1 x 1 piece is) though it would need to be twisted about 90*. It appears you had your's stick out 1/2" from the edge. I was thinking more like 2" so it would be easier to twist without affecting the body so much.

[George Geist]

Hi Michael,

Sorry. Poor choice of words on my part. Yes the stake goes through the loop created in the tape. And yes this does twist the loop 90 degrees. When I build my next tent I will still leave the loop sticking out just 1/2" but make the loop-tape only 1/2" wide. I haven't had any issue with loop twisting over that short distance on the mylar tent body when using the wire stakes. The wire stakes are only 1/16" in diameter. If you are using fatter stakes that fill up these small loops, then the twist occurs over a much shorter distance and you should consider a longer loop.

My thoughts about sticking out just 1/2" is that this allows me to stake the tent right to the ground if I want to, and if I wanted to stake it higher I can put a cord through the short loop.

If I made the loops 2" long, then I would take away my option to stake a side right to the ground if I needed to.

[Michael Ray]

I understand now. Thank you. I agree with your point, too – the 1/2" from the edge does increase your flexibility.

I gather you favor mylar over LDPE (at least for you vs Scouts that may not be as careful). How much noise does it make in the wind?

[Author]

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