Efficient way to fabricate a mold ?

It has been a while since starting this thread, wish the progress was a bit faster, but nevertheless, I am still happy there is a progress and it is going in the right direction.
Just want to report back and collect some comments and constructive critics.

I started in spring in a garage and over the course of summer had to move my workshop twice. This partially influenced selection of certain materials and methods along the way.

The plug was built using a combination of wire cut XPS foam, developed ply, melamine boards and 3D printed parts. Being on a very modest budget (e.g. no big CNC router), for modelling anything less than trivial 3D printer won hands down both in time and material cost.

The mould had the following composition: two sprayed layers of tooling gelcoat + hand-laminated 400g/sqm CSM + infused (1200 g/sqm 0/90 biaxial, 4mm lantor soric core, 1200 g/sqm 0/90 biaxial).
The mould laminate expectedly came not as heavy and rigid as traditionally would be suggested, but quite adequate for low volume production and most importantly light enough to be handled without special lifting machinery.

The first proof of concept part was infused in the mould using polyester with 450g/sqm 45/45 biaxial, 12mm divinycell, 450g/sqm 45/45 biaxial.

Overall, all stages went according to the plan. What needs some more attention is provisioning for the resin shrinkage and making the dimensional deviations more predictable, whether they affect the final look or not. 5-13% volumetric shrinkage of PE translates into ~ 2% linear, which is quite a substantial base figure to deal with. This 2% been affected by a ton of different factors transition engineering into art.

 

That looks very nicely done to me, congrats! Looks like a nice workspace too.
So what is it that you're building?