thanks all
This is the sumary of the process I used to make my miniatures.
Step 1_inicial concept.
Step 2_structure, it can be made of wire or wood, depending on the form of the miniature,(in this case just balsa wood).
Step 3_ filling the structure and obtaining a previous form.
Step 4_details(green stuff).
Step 5_resin casting.
I will start Step 5 on the fleet this week.
Concerning the planet devourer it is now on step 3.
1st filling aluminum foil, it makes the miniature lighter and is an easy and common material.
2nd filling modeling clay(I ran out of it
), modelling clay is quite cheap(about 2,5 € in spain), it is also very clean you just need water to clean it, but it is quite coarse(you cannot obtain details)
At this point if anyone is thinking on modeling anything, material costs would be about 4€, and depending on the size, betwen 2 minutes(a scort), and 30min-1hour (the planet devourer) depending on your experiece.