Without getting too complex 😆 from what I learned, it’s all about what bonding agent you use and the weave.
When doing the foils (pattern off an original (male/female sandwiched together) i had to soak four sheets of weave then lay it ontop of the releasing agent (white silicone stuff) then pour the bonding agent and nead through the weave, this was the hard bit as it’s bloody messy and you need gloves 😳 I used a squdge made out of wooden mallet. After pressing 4 male and 4 female weaves I sandwiched them together and clamped them hard, open both ends and two breathers in the mould, covered the whole “mould” with 1mm thick sealed plastci bag and then formed a nozzel for the vacuum which I placed midway along the mould. Enter a lot of suck at room temp and left to cure overnight. Came back the next morning to find some creep out of the mould (expected) and then opened out the mould and trimmed the foils down. Quite remarkably (for me) they came out straight and true with little trimming to be done. I then built up the top edge of the foil with move weave to fashion a union/junction for the tiller ext and did a similar thing to above except it was more freeformed and harder to vacuum well enough.
The fins were peasy compared to the foils so not really worth bothering to talk about.
I have bonded masts together and spar/shroud attachments/junctions without vacumming but to get the best bond vacuuming sucks out all the trapped air and oxygen nonsence that contributes to mass failure 😆