So I took my pair of leather boots to a cobblers to have the sole repaired, as it was coming away from the shoe, but I was told that they couldn't be repaired. I don't want to wast the perfectly good leather, so I joined this forum just to ask some cobblers about how I might be able to repair it. He said the shoe consists of three parts --a leather upper sewn onto a cardboard lower upon which the rubber out sole is glued-- and once the cardboard layer starts disintegrating, there is nothing that can be done. That this layer is disintegrating is no doubt the problem, as the threads are coming undone and the sole is falling off, but is this layer really just some type of cardboard? Why would a leather shoe be made with a material that would dissolve in a couple years?
I would like to be able to fix this shoe by pulling the disintegrating layer off and sewing on another material upon which to mount the sole. Is this something I could do? What material should I use?