Self inflating mat repair. Delaminated and goes flat. No puncture found. PIC

[Handmade Matt]

Hi guys.
I have a Mountain Warehouse self inflating camping mat. It goes flat after lying on it for a few hours, it's a slow leak.
I have failed to find a puncture using a spray bottle of soapy water and folding the mat over and pushing down to increase the pressure. The valve wasn't showing any bubbles either.
It does have some delamination going on, is that the cause perhaps? Air leaking under the outer green fabric layer which then slowly leaks out and is undetectable using soapy water?

Basically is it destined for the land fill or shall I try harder to find the leak?

Thanks for looking

 

[IC_Rafe]

Put it in a tub full of water, if you can't find something then, return under warranty if possible. Though with the delamination, i'd say it doesn't have a long life left.

 

[Handmade Matt]

Put it in a tub full of water, if you can't find something then, return under warranty if possible. Though with the delamination, i'd say it doesn't have a long life left.

Hi there. Thanks for your thoughts. I will give it another go to try and find the leak.
The mat was found left behind after this years Glastonbury festival so there'd be no proof of purchase.
It was holding air fine since it was found until just now.
If I can't work it out then there's nothing lost seeing as it was free.

I'm also about to make a repair on another self inflating mat that has an obvious hole.
I have a tube of Stormsure Repair Adhesive which is apparently up to the job but no "official" patch. I have some rubber patches that came with an inflatable canoe though and I have some inner tube patches. I might even try a bit of old tent material. I'm not sure yet.

 

[IC_Rafe]

Inner tube patches should work very well if you can find the hole. Or you could look into a small tent repair kit. Old tent material and similar won't do much, since that isn't meant to be airtight, but can be used as a patch to make it look better after fixing the actual leak.

 

[Handmade Matt]

Update.
I found the hole by testing again with soapy water spray and folding the mat over to increase the pressure.
I used Stormsure glue to fix it. It's amazing stuff, a patch-less glue dollop repair and it's held well. The mat's been inflated now for 24 hours and is still holding.
Happy days.
Thanks for your inputs.