Preparing Resin Parts For Painting
All the 1/72 scale diorama kits, accessories, etc. sold under the Full Circle Hobbies name are cast in resin. Resin is a type of plastic used for low volume production of parts and possesses some very different procedures for preparation and assembly compared to plastic.
The first step in the preparation of resin parts, is to sand off any parting lines and pour plugs. Then wash them thoroughly with warm soapy water. Common dish soap is good for this because it will easily remove the greasy mold release film from the parts caused by the casting process. If you don't wash the parts properly, paint will not stay on them.
Prime the parts with either an acrylic or enamel primer. Although white or grey primer is used the most, I find that flat (mat) black works better because it also acts as a pre-shade.
On most of my large diorama parts there's a thin lip around the casting. This is a sanding guide. Tape a large piece of 80 grit sanding paper to a flat surface and place the part on it. Sand slowly in a circular motion until the guide is paper thin or sanded off completely. A darker primer coat makes this process easier to see. I strongly recommend using a dust mask while sanding resin, as the fine dust created is very irritating if inhaled.
Once the parts have been sanded and parting lines and pour plugs have been removed, you'll need to fill any casting imperfections or air bubbles. Large imperfections can be filled with automotive spot putty which comes pre-mixed in a tube. For filling really small air bubbles, I recommend using Liquitex Matte Medium which is sold in a small bottle. It's an acrylic and can be brushed onto the area to be filled with a soft brush. Although I use Liquitex, any brand will do and Matte Medium can be purchased at any art supply store.
Once all of the imperfections have been filled and re-primered, it's time to glue the parts together. Sand or scrape the primer off any mating surfaces before gluing them to ensure a strong bond. The best glues for bonding resin to resin or resin to other types of materials, is 5 minute epoxy or CA glue. Regular glues made for plastics will not bond resin.
After all of the above has been done, you can now move onto the most fun part of model building, painting and adding details. For information on painting models, read my series of articles on this site. You'll find them very helpful.
I hope this article helps you with preparing resin kits for painting. If you have any questions or comments reguarding my products, please don't hesitate to contact me at firstname.lastname@example.org or leave a comment. Happy model building!
Owner of Full Circle Hobbies