Failing self-inflating mats

[Joe.B]

We’ve got a small collection of self-inflating mats. For light weight camping a couple of Thermarests and a couple of cheaper brand imitations, for car and big tent camps we’ve also got a couple of big Outwell mats.

Setting up the big tent at the start of a Tandem Rally last week I realised that the big thick double Outwell mat has failed, could be a small pin hole, or more likely a failed seem maybe. It has occurred to me since that over the past half dozen years we’ve had 3 mats fail in this way, all of them big thick Outwell’s, (the other two were singles however).

I’m wondering now whether it’s the increased depth that makes them more prone to failure or whether Outwell mats are just a bit naff?

Has anyone had any success in repairing self-inflating mats? They all have very slow leaks that are going to be very hard to detect.
 

[jdsnape]

I currently have a large SIM, also Outwell, sitting behind me in the office after having failed to find a very slow leak. The wife has suggested taking it to the swimming pool and looking for bubbles, but other than that I'm out of ideas

[Mrs Pingu]

Paddling pool or bath?

[Canardly]

Given that the majority of these products are not inexpensive and that technology has evolved to a stage where we can now glue wings to high performance aeroplanes why are such failures occuring and perhaps be considered acceptable?

[jsabine]

Because people aren't prepared to pay as much for a self-inflating mat as they are for a high performance aeroplane, so there's slightly less funding available for research into the properties of the most appropriate adhesive?

[mmmmartin]

Would suggest a bath of water and time to sit and watch for the occasional bubble. Then the adhesive patch they usually give you, and once you add the glue and patch, stick a pot of hot water on it for about 15 minutes. Seemed strange to me when someone suggested it but it worked a treat. Hasn't failed since and that was years ago

[drossall]

That's encouraging. I've just put my Vango mat in the bath after it let me down (literally!) on Scout camp. I've found a pin-hole. Not a failure, but a puncture. So I'm hopeful. As we're cyclists, has anyone tried regular puncture repair stuff? I'll try the kit that I think came with it first.

[mzjo]

I was going to post asking for reliable self-inflating mats and then I find this.
I have just had a cheap Decathlon mat fail (at least the second with this particular failure, I didn't keep all the dead ones to check) with the valve block coming unstuck from the mat fabric. Nothing slow with this failure, the mat is totally dead! I am thinking of trying superglue on it before I chuck the mat (it is a few years old, I don't think Decathlon sell them any more, so it doesn't owe me anything).

Are there any suggestions for reasonable lightweight full-size self-inflating mats? Needs to be at least 1m80x60cm wide, comfortable and packing small. Thermarest is the name I see coming up most often!