G'day, 

I'm making cycling shoes with resin infusion and have a slightly irritating issue in that it's almost impossible not to delaminate the toe box area of the sole when removing the concrete mould post cure. To address this issue, I'm thinking of the following process:

a) make a concrete foot mould as I always do --> turn it into a sole mould by adding extra concrete to form a toe box and a cleat platform
b) casting this concrete mould with alginate to make a flexible silicone mould
c) using this mould to lay up the sole for resin infusion 

Will a silicone mould work or will it simply deform under vacuum pressure of the bag? If this wont work, ya'll have any other ideas?

Ideally I would skip the first step altogether (because the enormous mess working with concrete makes does my head in), but I don't think its possible to mould silicone like concrete... but if you have a suggestion!?

Cheers!