Mechanical vs chemical bonding...
Chemical bonding causes the two materials to become one at the joint. Example: Plastic welds... chemical between two pieces of plastic, chemically melts the plastic together. Works well on things that are the same type of material.
Mechanical bonds are those which the glue used is between two different materials. The bond between both sides has to be strong or the bond fails.
Silicone is something that bonds physically to the material, but doesnt do a very good job of it because its tensil strength is low. You need a different material to use as the sole of the shoe, or you need a different way of attaching it. Possibly stitching a piece onto the sole.
Shoegoo is self vulcanizing rubber, it is workable until applied... I think it hardens only in air, maybe oxidation... dont know all that much about it. But, it is also a mechanical bond. It peels off almost as easily as the silicone, because its intended use is a bandaid!
I'm wondering if some of the epoxys that are out now are flexible enough to be used as the sole of a shoe, they have extremely high yeild's! On fiberglass boats you can use some stuff that 3M makes called 5200... stick a piece of metal to the fiberglass, it will pull the fiberglass apart before the bond between the metal and the epoxy fails!
I think I've got the terminology right for most of those... been awhile since I took physics!
