Envirotex not tough enough?

[Young Salt]

Now that i've fished the plugs i've made over the winter, i'm finding that they are getting beat up quickly. Some of the damage is from rocks but alot of the damage is from the treble hooks. On a few plugs the belly hook wore through the epoxy, down to the bare wood on some.
Is this normal from envirotex? Could it be that i didn't mix the two parts equally? I know i mixed them long enough.