Army issue goretex Bivvy bags, shelf life?

[lostplanet]

The last couple of outings my sleeping bag has been wet in the morning. Pretty sure i've nikwaxed this bag and it will get done again.

The issue date is 2004 and it has been used fairly regularly, no holes or damage and it seems more like condensation maybe?

last night was under the basha with plenty of ventilation, I'm not expecting miracles, is it time for a new bag?

 

[Oliver G]

I think mine is from 2000, I think the only difference bar 4 years is I haven't treated mine with anything. The only time I find my sleeping bag gets wet is if it is windy and I pull the large side of the flap over my face while asleep.

Next time you're out tuck the top flaps inside the bivvy bag and see if it gets wet, that way it rules out unintentional condensation at night, if that doesn't work then it's time for a new bag.

 

[lostplanet]

I think ill stick it in the back garden with some towels in it and see what happens over night.
Id be surprised if it was condensation as there is quite a bit of moisture or more than i'd expect.

About time I got another one, MTP New around £50 sound about right?

 

[Oliver G]

Write on some loo roll with pen and put that between the bivvy bag and the towels, if it come out smudged then the loo roll has wicked up some moister and gotten wet.

Check out firestormkit.co.uk they have one for about £40.

 

[MrEd]

Mine is a poly warm one dated 1999 and the footbox is now leaky, I have managed to repair it but tbh I am expecting only to get another year or 2 out of it. I have had it over 15 years, it came to me via a mate in the army who was issued it new for his tour in Bosnia so it has had some consistent decent use, and tbh I am surprised it had lasted as long as it has, I dont particularly molly coddle it.

I have a Dutch hooped one aswell and both suffer from a bit of condensation when cold, but less so when warm and wet.

I also always use a tarp (mainly so I have dry admin space

I will just replace the green bivvy with whatever is the most recent dated one I can find.

 

[Dogoak]

Have you washed it? Dirt clogs the pores of GTX.
If it hasn't then I'd make sure it's clean, before Nikwax treatment.

 

[MrEd]

Have you washed it? Dirt clogs the pores of GTX.
If it hasn't then I'd make sure it's clean, before Nikwax treatment.

this is key to keeping the goretex breathable.

i use Nikwax tek wash before using the reproofer

 

[Erbswurst]

Unsure, but I have heard, that you shouldn't forget to rinse them excessively!

Because if the detergent stays in the GTX pores, they aren't waterproof anymore, if I understood it right.

 

[Dogoak]

Unsure, but I have heard, that you shouldn't forget to rinse them excessively!

Because if the detergent stays in the GTX pores, they aren't waterproof anymore, if I understood it right.

Correct.

 

[lostplanet]

Yes, I had several paramo garments for a while so should have some around still.

I'm liking the new MTP one though, as it looks bigger too.

 

[TLM]

Because if the detergent stays in the GTX pores, they aren't waterproof anymore, if I understood it right.

A detergent especially ones with tensides can change the films response from hydrophobic to hydrophilic and so allow some water leakage. Tensides also affect DWR treatments and in some cases also waxed fabric. So only use natural soaps if a wash is needed and rinse more than usual as the soap itself can in some cases have similar effects not speak about blocking the pores in films.