Need a new Bivi Bag!

[Dan00001]

I’ve be wondering how on Earth my sons NATO pup tent can be leaking and wondering whether condensation could account for it.

@Dan00001
Have you got a survival bag - one of those orange heavy duty plastic bags? I think Karimor do/did them.
In theory you could replace the bivi with one of those in a safe location.

You say that the bivi survives a prolonged spray test? This would help you gauge how much water was coming into your bivi from inside. While nothing comes through the plastic from outside, the plastic bag represents just about the worst case scenario for condensation.

I do, but I don't think they would last very long in the typical places I get put. When I was out, I wasn't breathing inside the bivi, and it started raining after I got in so I wasn't that wet getting in. I also wasn't sweaty getting in as it to get to the location was mostly a flat, non strenuous walk. I really don't think condensation was the issue, I've camped in my Dutch hooped bivi and didn't wake up wet.

The test I performed at home was just draping the bivi in a way in which it would collect water and then I poured half a litre or so in that one area and zero water penetrated through the membrane. But, that is very little weight. When I'm laying on top of the bottom layer of the membrane, there will be much greater force to push water through from underneath?

My next plan is to get in it in the bath and see what happens

 

[MikeLA]

Look for older good quality versions, but they are still the best for the price bivi bags tried others like alpkit and hated it.
The above advice on ironing and proofing may do the trick.