Sand Paint Repeat

Custom Lego Minifigure Parts

What to watch out for when giving your model, figure, or 3D print a glossy finish. Knowing the correct procedure can make it easier and save you both time and frustration. Read on to see what to avoid as we prep the Lego Minifigure couple for their big day.

There isn’t any quick way to get a smooth glossy finish on a plastic model, the best results involve time and ‘elbow grease’. However the more effort you put into a base surface and priming coat the easier it is to finish the layers you put over it. For the wedding Minifigures it didn’t go as planned, resulting in days of trial and error. Each mistake blew out the timeline as it required the paint to be dry before any fixes could be addressed. A great first tip is to be patient, let your surface completely dry before attempting to fix it. Anything done to a wet painted surface will create a horrible sticky mess, and cost more time to then further fix.

Undercoat Lego Minifigure 3D printed parts

When wanting a smooth even and glossy surface on your finished model, spray painting is a very cost-effective way to achieve a great result. Applied properly, spray paint can help hide irregularities and give off an even colour finish. With each positive there is however a negative, the nuances of spray paints are not always mentioned with how-to videos or the can’s labeling. Be aware that some colours of paint are oil based and some are water based, this includes ‘undercoat’ sprays too. If they are only touch dry when applying a second coat it can react and ruin your intended finish, or not adhere properly to the model itself. This even applies to different colours of the same brand.

One of the issues we faced was the reaction of the glossy top coat on the undercoat primer. The surface would ripple and look like a dry creek bed. After some follow up testing it was due to the incompatibility of the top coat to adhere to the primer. The result was to sand it down and spray again, and while the initial intention was to use enamels in order to get a high quality finish. With the increased drying time and complications of surface finishes we had with the whites and yellows, we ended up using a citadel paint and air brush, finished with an acrylic clear coat.

Lego Minifigure extra large 3D printed model parts

Traditionally when dealing with glossy surfaces and enamel paints the finished surface is left to dry and becomes a hard high gloss. However when working with so many irregular shapes there would always be a dust speckle or hair, or pool of paint on each part of the model. We even had issues with un-even drying that would result in fingerprints left here and there. The workshop didn’t afford a dust free environment and any fix would require recoating the entire piece. Our result, while more labor intensive, proved to be much quicker and not be so fragile. We sanded and polished each component instead of relying on the paint to cure without flaws. With a glossy paint applied each part would be wet sanded with increasing grit from 400 to 1200 and them polished on a buffing wheel with a mirror coat car polish.

Minifigure Lego custom parts printed model

This process gave a great and consistent result, as the more time spend sanding and polishing, the better the finished surface. This has now been adopted for all future projects as the go to for a high gloss and mirror finishing.


Molding the Bride To Be

3D printed and cast lego minifigure parts primed

Giraffe and Elf was lucky enough to be given the opportunity to create a large pair of Lego Bride and Groom Minifigures. Having developed molds for these in the past it sounded simple enough, follow along as we take you through how these figures were prepped as a gift for the big day.

Having already made a set of molds for a 10:1 XL scale Lego Minifigure the most difficult part of replicating the little plastic models was done. However the RVT silicone molds of the minifigure parts had been in storage for a while and weren’t optimal for repeated casting. When used in the past each cast part required a lot of clean up and fixing. Along with the casting both the bride and groom figures needed additional custom parts to be able to stand apart.

The custom parts were modeled in Maya using LEOCAD geometry from the Lego Minifigure library. With details added, cleaned, and prepped for 3D printing, the Grooms Hair, Brides Hair, and Brides Dress/legs were all additionally 3D printed for this project.

lego minifigure groom hair 3d model

With the unique parts being printed, the next task was dusting off the silicone molds and casting the rest of the common minifigure parts. The cast parts all came out well with some flashing and only a few air bubbles, getting these parts ready for painting wasn’t going to take long.

lego minifigure parts cast in silicone with flashing and sprues

The XL minifigure molds were the first two-part silicone molds made in our workshop and as such had some errors in their design, with air getting trapped and undercuts. The most difficult parts to cast were the arms, the arm mold consists of four shallow halves sitting side by side with the pour spouts on the face of the mold, rather than in the seam or separation. This mold has two pour holes per arm half and requires allot of rocking to get the air out as the resin hardens.

lego minifigure parts cast with two part epoxy unfinished

The result of the poor mold is lots of trapped air bubbles, lots of flashing, and general mess as the casting polyurethane leaks out everywhere, however this all happens on the insides of the arms and isn’t seen once the parts are glued and assembled. As the molds have been sitting in a box for nearly four years and the rough handling it requires to get the cured parts out, it is a good example of how good mold design makes it last longer. Three of the molds we used tore as we were taking the casts out meaning this may be the last time we make any new XL Minifigure castings.