Under-tarp tent/ bug bivy discussion

[Frolicking Dinosaurs]

I travel with a male dino. While he is a really nice dino, he is set in his ways and stubborn (his mother once told me there was a mule in the bloodline on his father's side).....

The dinos carry a large (10 x 12') silnylon tarp. Both dinos dislike bug or rodent company at midnight so like to sleep in some sort of enclosed area. The she-dino would gladly sleep in a no-u-see-um tent with a silnylon floor, but the he-dino likes to be enclosed in an opaque structure (we stealth camp so privacy isn't a real issue....).

First question - has anyone made or used something akin to Black Diamond's Betamid bug tent (http://www.bdel.com/gear/beta_bug.php) from uncoated 1.1 or 1.9 nylon or even woven polyester? I was thinking of using silnylon up the walls to about 12 to 18" (to prevent heavy splatter from misting thru) and then using uncoated fabric above that. Would the uncoated material allow the condensation to soak in to the material and evaporate from the other side if no no-u-see-um net was used?

I'm thinking of making this with two doors (similar configuration to Double Rainbow (http://www.tarptent.com/doublerainbow.html) and Lunar Duo (http://www.sixmoondesigns.com/shop/shopexd.asp?id=47)) with the head end much taller than the foot end (similar to this (http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=7899) with two suspension at the head points instead of one)

Second question(s) - would having zippered 'D' doors on the sides be too much weight / strain while zipping / unzipping for an overhead tarp? Would a single 'inverted T' or 'L' door at the head be more stable?

[rgarling]

sounds like you are getting ready to invent the tarp tent

[Frolicking Dinosaurs]

Similar for sure -but in two completely seperate parts that are fully functional alone - the tarp (10 x 12' silnylon) and the tent:
The tent could be used in a shelter like a bivy for bug / rodent protection & extra warmth or used alone in warm weather without any danger of rain or even used indoor in accommidations that left one with concerns re: bugs & rodents (not so much a problem in the US, but dinos don't just sleep in the US)
The tarp would just be a standard tarp with all the uses they have - except I'd add a few extra attachment points for the under-tent.

[Footslogger]

If you want to keep it light and go floorless you could always consider the OR "Double" Bug Bivy:

http://www.epinions.com/pr-Tents-Outdoor_Research_Double_Bug_Bivy

OR doesn't make them any more but they can be located on-line for a lot less than they originally cost. We got one last year and use it under a tarp when we hike together.

'Slogger

[Frolicking Dinosaurs]

'sogger, if I could talk the he-dino into going wall-less, I would jump on that OR bivy, but alas, the he-dino (and his mule bloodline) will not budge - and he's too cute to leave behind :D

[Appalachian Tater]

FD, have you considered a Double Rainbow from Henry Shires? Sounds like it would be perfect for you.

[Frolicking Dinosaurs]

I have crawled into both the double rainbow and the lunar duo. Because of my ortho problems, I can't get out of either one without serious difficulty. HopefulHiker was with me at this year's gathering when I tried the Lunar Duo and Ron "Fallingwater" Moak had to help the male dino get me out. Maybe one of them will drop by and let you know just how hard it was.

[general]

with any enclosed area with ripstop or whatever, i think you would have condensation problems. you may have thought about this already, but could you use an opaque material for the floor and walls with a netting roof that would be obscured by the tarp material anyway. just a thought.

also with a tarp setup i think a T door is best.

[hammock engineer]

Here is a little advice that may help from the world of hammocks.

I recently made a hammock sock. Basically a big tube that goes over the hammock to trap in heat and block wind in the winter. The bottom 2/3 is 1.1 oz DWR ripstop and the top 1/3 is 1.1 oz uncoated. I spent close to 12 hours in it one night. I had some condensation. Enough to feel, but not enough to worry about. Yout tent is going to be 3-4 times the size. Based on what I saw in mine (insert all the disclaimers here), if you use all non-coated except for the floor you will have some condensation, but not a lot.

Jeff and Risk also made some hammock socks/travel pods. They talk about it on their site. Might be some helpful info concerning condensation.

You could add a section of noseeum at the top to vent some of the mosture. I was thinking about adding one to my project, but I think it would vent too much heat for my purposes.

[hammock engineer]

Not to highjack the thread, but where are you guys finding "L" shaped zippers? I am going to try OWF or thru-hiker. I don't know anywhere else to try. I need one for my bug bivy project.

[Frolicking Dinosaurs]

HE - an 'L' shaped zipper is actually two zippers that meet to form the 'L'

[Frolicking Dinosaurs]

I think I will add a 4 to 6" wide strip of no-u-see-um to the top of this structure to vent condensation. I'm also considering adding a 1" horizontal strip on the shorter end (toward the top of that side) to promote convection within the tent and help remove moisture.

[rgarling]

You can make a bug bivy that could mate up with your tarp. I made a large bug bivy for one, with a sil-nylon bottom/foot and a screen top, w/an L zipper along the bottom and up toward the attachment point at the head.

I suppose you could make a double, with zippers on each side.

Unfortunately, even with sil-nylon, the bivy added about a pound. I ended up buying the new model tarptent.