I have never before worked with resin materials, so I did a bit of research on what to do.
Apparently, when casting a resin model, some manufacturers place a mold release agent between the mold and the resin that is poured in. As the name states, this releases the resin casting from the mold.
Before assembly, you should quickly wash the resin pieces in luke-warm water with a bit of soap in it. This removes anything which may prevent your glue from adhering or the undercoat from going on smoothly.
I filled a plastic container with dish detergent and luke-warm water and submerged the pieces for a few seconds.
Then I rinsed each piece and dried them off and then left the pieces to sit for a while to dry further.
So then... I'm back.
4 days ago