Hi all,

I've got a self inflating mat that has a very minor leak over a few hours. I've had it in the bath and cant find any leaks and i've tried to iron the seams to see if that helps but it still goes down. Any other ideas? is it worth trying a tent seam sealer?

TIA,

Rob

If it's an insulated mat then sometimes bits of the insulation can get caught in the valve and cause a very slow leak. Might be worth checking.

I've had a similar problem to what Whitestone mentions above with my Exped Synmat. Every so often it loses pressure overnight, I've checked for leaks in the mat itself and can't find any so have concluded that the problem is the plug that goes into the inflation port. When I've had the problem, pulling the plug out and cleaning it and the port has always resolved the issue but obviously having to do that in the middle of the night is a PITA and I'm not sure that I'd buy another Exped mat as a result. It's worth checking the plug/valve on your mat though in case you have a similar problem.

This is self-inflating so foam cored.

I found the best way to find a slow leak was to slightly over inflate the mat and then pour water slowly (from something with a spout like a water bottle) over small sections of the mat and listen. The escaping air makes an hissing sound when there is a very thin film of water over it. It needs to be quiet when you do this!

Mix a little washing-up liquid in a spray bottle, inflate the mat, then spray it with the solution. Do a small area at a time and look out for small soap bubbles.

Jurassic wrote: ↑Wed Sep 01, 2021 11:37 am I've had a similar problem to what Whitestone mentions above with my Exped Synmat. Every so often it loses pressure overnight, I've checked for leaks in the mat itself and can't find any so have concluded that the problem is the plug that goes into the inflation port.

If you inflate a mat in the late afternoon/early evening sun with a significant volume as eg a Synmat HL, you may find that once night has fallen and the temperature has dropped, the mat looses some of the initial pressure due to the air inside cooling and thus contracting.
In such cases I give the mat more air before going to 'bed'.

ScotRoutes wrote: ↑Wed Sep 01, 2021 8:10 pm Mix a little washing-up liquid in a spray bottle, inflate the mat, then spray it with the solution. Do a small area at a time and look out for small soap bubbles.

That's what I usually do and has helped find weak leaks. Although, I don't use a spray bottle, just a sponge. Works too.

Alpinum wrote: ↑Wed Sep 01, 2021 8:38 pm

Jurassic wrote: ↑Wed Sep 01, 2021 11:37 am I've had a similar problem to what Whitestone mentions above with my Exped Synmat. Every so often it loses pressure overnight, I've checked for leaks in the mat itself and can't find any so have concluded that the problem is the plug that goes into the inflation port.

If you inflate a mat in the late afternoon/early evening sun with a significant volume as eg a Synmat HL, you may find that once night has fallen and the temperature has dropped, the mat looses some of the initial pressure due to the air inside cooling and thus contracting.
In such cases I give the mat more air before going to 'bed'.

Not the problem in my case, it goes flat during the night and my Synmat is my winter mat (I use a NeoAir X-Lite for the other three seasons). It's definitely the plug not sealing properly, usually caused by a bit of grit or sand getting into the seal part.

Just to follow up on this, i've finally had it in the bath and found the leaks. They were only apparent when the none submerged corners were folded over. Its not the valves but the material around the valves. The valve body tapers to a point but the two layers of material cant seal to the point of the valve body.

Not decided whats best for a repair, some form of silicone or just superglue?

I had success with some Stormsure adhesive.

I had the same problem with a multi mat self inflating mat. I put it down to protruding valve design causing flex on the material around the base of the valve.