Can't remember if I ever uploaded these after I pulled apart andrewa's Exped Downmat to see if it was repairable. Thanks to him for sending it to me so I could break it open and have a look inside.
I got a cheap temperature adjustable iron off aliexpress that I found while researching TPU and packraft materials. It turns out the exped material is very similar and came apart very easily, and I should be able to melt it back together if I want to. Hopefully it's totally possible to repair an exped inflatable mat with an iron and some spare material for baffles.
Took me a while to get all the down out into garbage bags, never worked with down before and it's a PITA. I vacuumed the remainder of it up and it clogged the filter pretty quick
Inside the mat you can see that the baffles all failed similarly by splitting along the length. They're heat sealed to the top and bottom of the mat, there's no glue. So it's not a delamination failure, it's just a too thin and brittle plastic used to make the baffles.
I have some TPU backed packraft cloth and I'd like to fix it up, but it will require a lot of patience so I'm not sure it's worth it. If anyone else has failed mats they can send my way for parts or investigation I'd love to hear. Just picked up a Nemo AstroAir today with a few failed baffles and it'll be interesting to see if it's a similar issue and fix.