Vapor Barrier/Undercover

[cardo]

I'm on the Left Coast and will be hangin in 'above freezing temps'. I have a DIY hammock and a JRB Shenandoah for a UQ. I'm thinking of making an undercover as a windbreak and protect the UQ from splashing rain. I was looking at this material from DYI Gear:

"30d Ripstop Nylon, Metalized reflective coating one side. DWR. 60" wide.

Navy Blue or Green

30 Denier Ripstop Nylon with metalized reflective coating on one side. This material can be used to reflect heat in insulation systems very effectively. You will be amazed at how much heat comes back.

This material is not breathable, so it acts as a vapor barrier, so if used in sleeping bag or quilt systems be sure you know how to manage moisture properly. We have been using this very effectively in making freezer bag cozies with Insultex or Climashield as the insulation."

This would be suspended with shock cord in the side channels and drawstrings on the end. (The UQ is hung on the hammock.)

Will moisture be a problem if the undercover is taken off each morning? Any moisture/condensation would be on the undercover and pool there? As long as there was only windblown, incidental contact between the UQ and undercover (the underquilt isn't sitting in a puddle)...? Will an undercover add a few degrees of warmth to the equation? Is there a more suitable fabric? Good idea/Bad idea?

All thoughts welcome

[PuckerFactor]

The only problem with that might be that your vapor barrier is on the outside of your insulation. Generally, you want it next to the hammock, so that the water vapor doesn't condense in your UQ.
In this situation, I think I would be more inclined to bring a breathable DWR UQ protector, and a space blanket to lay between the hammock and UQ. I don't know what the weight of the metalized 30D nylon is, but there might be a small weight difference.

Hope that helps,
PF

[Shug]

I used my ULA RainWrap (silnylon) a few times as a weathershield.....hung it loose and had no moisture. Coulda just gotten lucky.
Shug

[BillyBob58]

I used my ULA RainWrap (silnylon) a few times as a weathershield.....hung it loose and had no moisture. Coulda just gotten lucky.
Shug

Yep, if it hangs loose you might get away with it. But it will be cold, and vapor that hits it will condense. Or, you could put a VB or space blanket between you and the UQ and very close to your hammock- to keep it warm- and then you should not have any condensation. Probably not, but you will need to experiment where you can bail safely. It always works for me. Also, with and exterior wind/moisture block combined with an interior VB/reflective barrier. you can expect a very significant temperature boost. But using a VB only on the exterior, you will really have to guard against/watch for condensation.