Hi Dave. I’m currently making a packraft and have unfortunately damaged the TPU coating a few times now myself.
I am surprised to hear that water is passing through your fabric though, even with a damaged TPU coating…
To my understanding, the fabrics sold through Matt’s site have a PU coating on one side in addition to the heat sealable, TPU coating on the other. In which case, the fabric should still be impermeable to water.
Matt – are you able to shed some light on why this might be happening?