I was in the same boatith the boots. I cleaned the area real good and used 3M 5200 Marine grade caulk. So far after many miles, the soles are still on and going strong. I did buy a pair of Bitterroots as a replacement. I wanted the cloth style but read nothing but bad reports on the soles. I just hope the Bitterroots last as long as my first pair Vasque, 15 years. It took 5 years just to break them in. They were the best boot I have ever wore. 15 years ago they were $185, The new ones I just bought were $219. I hope they are a good investment. Try the caulk!!
Capt Eddie - - (or anyone else that's tried the 3M 5200 marine caulk:
I spoke with the folks at 3M, who indicated that the 3M 5200 attacks rubber and shouldn't be used on it. I'm curious to know if after a year or so of use, whether the marine caulk repair is holding strong. 3M recommended a different product (2-part epoxy DP 100+ or the thicker and longer wet working life DP 110). They claimed these are still flexible after curing, but i attempted to replace the rotted polyurethane foam from the heal with the 110, which was about 10mm thick, and while it cured nicely without access to moisture, it wasn't very flexible. In the heel, it might be fine, as the heel doesn't need to flex that much. For anyone considering using either glue, I highly recommend using a wire brush or some other method to remove ALL of the PU foam so that the glue is attempting to adhere to rubber rather than a failing foam on both sides.
Anyway, I'm curious to know what your experience has been.