After waxing you must make barriers for vacuum bag. I used 2mm plastic for that. Pieces just hot melt glued to bonnet and some aluminium tape for seams.
When the barriers are in place it’s time for first gel coat layer. Gel coat should dry (usually 1-2 hours) to sticky before applying second layer. I used at first layer gray and second layer black gel coat because if you have to repair etc. the mold you can see layers and you won’t sand through to glassfiber.