Hello, lt's Go on.
The pieces printed with the 3D printer, however precise and of quality they are, have small jaggies which, if not corrected, would leave fingerprints on the printed piece. So I sanded the interior first with 120 sandpaper, then 200 and finally 360. I then gave a nice coat of catalyzed spray filler and then a varnish with 2K acrylic paint. The result was mirror surfaces!
Those who are somewhat familiar with composite molds know that every new mold must be treated with a release agent before molding. So you need to get a release wax for molds (you can find it in all online shops of modeling or composite processing items (I use Sorvolando Compositi "sorvolandocompositi.it" cost about 25 euros for a 400/500 gram jar which will lasts a lifetime and, which creates added value, a person who knows how to give you lots of useful advice). This wax must be applied inside the mold with a soft cotton cloth with circular movements being careful to treat all points of the mold and the upper part where the fabric and the resin will overflow). 7/8 coats of wax (each coat interspersed with air drying for about twenty minutes and light polishing) for a new mold are sufficient. In subsequent pressings he was able to give only a couple of coats of wax. After the wax, I also use polyvinyl alcohol given with a spray gun / airbrush: it is an additional release agent that forms a water-soluble film and which helps the extraction of the molded piece (someone does not use it).
