Hi Gabriela,
I’m going to break this down with how I would approach it:
A clear polyurethane, not epoxy, would be my resin of choice in this case. A polyurethane will adhere well to the wood without much shrinkage. You can also cut and polish cured polyurethane resin, which epoxy doesn’t always do well with.
In order to get it as bubble free as the pin shows, I would pressure cast it. That’s going to require a set up that might be rather costly ($1000 or more).
We don’t sell clear polyurethane resins. In this case, I would recommend you contact the team at Alumilite (www.alumilite.com) They should be able to help you with large quantities of resin and give additional project advice.
Good luck!