I’ve cut a design into carbon fibre that I’m reinstating with clear polyester. The design is quite intricate and fine...think of it as a shallow channel about 1x2mm cross section in places, but about a meter long with branches off it etc.

To exclude Air I’m filling it from the bottom of the design with a syringe. I’ve got a silicone mould on top of it, but I’m getting a lot of seepage at the interface so a lot of excess resin that I then have to remove.

What’s the best way to seal the carbon fibre/silicone interface so that this does not happen?