I highly recommend checking out BSI products(Bob Smith Industries), super glue cyanacrylatecyanocrylate (CA) class glues. I have given up on the cost and failures of cobblers and have had good success with their Insta-Cure product for repair on the soles of hiking boots so for years. I have just found out about their IC-2000 rubber toughened flexible product and will be trying it out. My most recent repair was on my Wetland Muck boots. Both entire soles failed at a year of use; such shameful diminishing of quality in manufacturing. The Insta-Cure was used for this application. Store all CA products in the frigfridge to greatly prolong useful life.