Pikachu Serving Plate - Coloured Concrete

This Instructable shows you how to use 3D printed mould to create concrete Pikachu plate. Concrete plates like that can be used as serving platters, table centrepieces, trivets for hot pots and pants or as a very sturdy placemats. 3D printing the moulds allows you to engage your creativity and make interesting and unique pieces of tableware that I guarantee will become a star focus of your dinner guests.

You will need:

1. 3D printer
2. Melamine board
3. Glue gun
4. Super glue
5. Concrete mix
6. Pigments (optional)
7. Two part epoxy glue + acrylic paints
8. Sanding paper
9. Concrete polishing pads (optional)
10. Release agent
11. Disposable containers
12. Spatula, box cutter
13. Food safe concrete sealer

Find your design and, if necessary, manipulate the picture in a photo editing program to remove all colour and shading. You need the picture to be as clean as possible in order to create a clear SVG file.

Convert pictures to SVG files using https://convertio.co/jpg-svg/

To manipulate the picture I simply used Paint.

1. Pikachu had too many fingers. They were too small for casting, so I had to edit the picture and create 3 fingers instead of 5, thus making each finger bigger and ensuring all of them will be visible once casted.
2. I removed black marks from the ears.
3. Once that was done, I converted that picture to SVG.
4. I removed all inside lines from the sketch, leaving only the outline and converted that to SVG.

I imported both SVG files and created two separate objects in one document. I made the outline object 20mm thick and the other one 1mm thick (3rd picture). I aligned and joined them together.

I sliced it into three parts before printing.

1. Pikachu frame will be destroyed, so to make it easier, I printed it at 5% infill, 0.8mm wall thickness and 0.3mm layer height.
2. Once printed, I glued it to a board with a glue gun. If your frame has tight spots (4th picture) and your glue gun nozzle can't get in there, use Blu Tack instead.
3. I used superglue to adhere the thin inside pieces flat to the board.
4. Any parts that didn't attach to the frame (mouth and eyes) had to be printed separately and glued to the board.
5. I printed mirrored Pikachu picture, cut it out, placed it on a board and used a permanent marker to draw over the eyes and mouth. Permanent marker bled through the paper and left enough marks to help me with attaching the 3d printed pieces to the board.

Superglue has to be used very, very sparsely. Only use the tiniest drop on either end of the object and hold it in place until it sets. Any more of the glue and it won't come off the board once concrete is cured.

I like to use Vaseline and a brush because it allows me to control which areas are to be covered and which should be left as they are. In case of Pikachu, everything on the inside was covered with release agent except for the eyes, because I wanted them to stay imbedded.

Before Vaseline, I roughly pencilled the ear pattern on the board. Once Vaseline was on, I mixed a small batch of black concrete to make the ear spots, poured it in and used a stirring stick to shape it as necessary.

Due to COVD restrictions, concrete and cement are difficult to get at the moment, especially white cement, so I had to use the last of my supplies as I couldn't get anything in the store. This resulted in a tiny mistake, but it was easy to cover it up.

1. I mixed cement with yellow pigment and I set about 1/4 cup of that powder aside (it will come in handy in case cement slurry has to be used).
2. I added small aggregate and poured the concrete mix it into the mould.
3. I vibrated it with a sander to get rid of any air bubbles.
4. In the end I didn't have enough yellow concrete to cover the mould to the top, so I pushed it around to make sure all edges were covered and let it dry like that.
5. After few hours, I added a thin layer of regular grey concrete and levelled the back of the mould.

1. I let the concrete dry for 12 hours before I removed the mould.
2. Glue around the edges was very easy to unpeel since I used melamine board.
3. Once glue was removed I used a box cutter to gently pry the edges of the mould from the board.
4. I placed a spatula it in the slit between the mould and the board and used a hammer to gently tap the spatula around and pry the concrete away from the board. It was very easy to remove, since I used Vaseline liberally. Some parts of the mould even popped off on their own volition.
5. Once the mould was pried off the board, I flipped it upside down and gently removed all inside parts creating the cavities. It was really easy, they were coated in release agent, so they weren't imbedded in concrete.

The one part I wasn't gentle enough with, was the right eye (as seen in picture 4), where I not only managed to pry the eye off, but I also crumbled some concrete around it. Evidently it wasn't cured enough, so for just to be on the safe side- cure the concrete longer than 12 hours.

Once Pikachu was out of the mould, I left it to cure for 2 weeks.

I used long curing epoxy glue, which is a much better option for this project because I didn't have to mix multiple batches of glue and paint. I simply poured a decent amount of epoxy and mixed it with acrylic paint. I used a toothpick to fill the cavities with coloured epoxy and made sure the level of epoxy was as level as possible (if you overflow the cavities, you will have to sand them down, which takes a long time).

Two part epoxy glue, when mixed with acrylic paint, takes anywhere between 1 and 7 days to cure fully. When it first sets (within 30-60min), it resembles rubber. Which is kind of a good thing, because if you mess something up, you can wait 30min and just peel everything off without any problems. It takes days however to fully cure and be ready for proper sanding. You will know it's ready, once it's hard to touch and if you poke it with your fingernail, it won't show any indentations.

Once epoxy was hardened, I sanded the entire surface with coarse sanding paper and since there were a few remaining vaseline globs around, I also washed it with soap and a brush.

Once dried, the surface revealed a few small holes and nicks, so I had to apply slurry. Remember when I told you to put aside 1/4 cup of cement mixture (step 5)? This is what that reserved cement was for. I mixed it with enough water to create a sour-cream-like thick paste and rubbed it where holes needed to be filled. I also used it to fill the crumbled concrete around the eyes. I left it to dry for a couple of hours before I was able to sand it.

I sanded with medium to fine sand paper and since I didn't overflow the cavities with epoxy, it didn't take long.

Just to be on the safe side, I put it aside for few more days before I finally applied varnish. Since I plan to use the plate in the kitchen, I used food safe concrete sealer, applied accordingly to the manufacturer.

Before I applied the sealer, I played around and used a permanent marker to draw the outline. I didn't keep it that way in the end, I washed it off with water and a bit of fine sanding, but it looked pretty good either way. I'd recommend using a marker to draw the outline (it's very easy, marker tip just glides along the edge) and then go over it with a fine brush and black acrylic paint before sealing.