Introduction: Mario Kart 8 Themed Room

About: I am most well known for my various Video Game themed baby nurseries, most recently, Mario Kart 8. I enjoy the challenge of making things using materials and processes that are new to me. The sense of explorat…

In this Instructable, I will walk you through the process of designing and building a Mario Kart themed room that we used as a nursery. This can be a big project utilizing a variety of processes and materials to hopefully all come together as an incredible place for you and your family. Hopefully, many of the ideas and techniques used here can help you on coming up with your own nursery, regardless of the theme!

There are many stages in the creation of this room, and each may have their own unique tools and materials. I will break them down here and link them in the individual steps as well:

Painting the Room:
Paint Roller -

Paint Roller Covers -

Latex Paint Brushes-

Blue Painters Tape-

Recommended Brand of Acrylic Paint:

Assorted Acrylic Brushes:

Creating the Kart and Mario's Body:

Apoxie Sculpt-

Bondo Spreader-

Creating Mario's Heat and Hat:
Monster Clay -

Clay Sculpting tools-

PlatSil 71-20 Silicone Rubber:

Plaster bandages:

EASYFLO 120 Casting Resin:

Blue LED lights-

LED 12V Power Supply-

Single Color LED Remote Control:

Cutting Mat for Light Diffusion:

Step 1: Assess, Visualize, Mockup

At the very start of this project, after deciding on the theme of the latest installment of the Mario Kart franchise, I got to work! I began by measuring and recording the layout of the room while visualizing what potential elements could go where after taking into consideration the doors, closet and windows. It's important to decide what wall will be the centerpiece of the room. The most logical selection here was the wall seen right as you enter the room. Pretty much everything grows from this place outward.

I brought the room sketch and dimensions into Photoshop and proceeded to mock up the layout and positioning of the main elements of the room. Placing different components on separate layers allows you to quickly move, rearrange and tweak the positioning, scale, and relative placement of many elements. After the design was mostly decided upon, I proceeded to draw out a grid over top of the entire piece. A grid is a very helpful tool when dealing with reproducing images onto a large surface. Scaling elements properly and keeping everything aligned are a breeze using this classic method. For this particular grid, one 1.5" square on the page (printed to scale) equaled one foot on the wall of the room.

Step 2: Prepping the Room

Every big project starts with a first step and this was ours. Patching holes on the wall and painting the base coat of indoor latex paint. Tape up the windows/door frames, spread the drop cloths, and break out the paint rollers. We decided upon putting up chair rail molding to give the mural a base that was up closer to eye level. For a typical room with 8 foot ceilings, 32 inches is a pretty standard height. We applied a light blue for the sky and then painted a darker blue from the baseboards to the 32 inch level. Pretty straightforward homeowner painting duties here...

Step 3: Happy Little Clouds....Art Time!

After the latex paint was well and dry, I had to make a decision that I needed to try to carry forward thru the entire paint job. The Sun. Where was the primary light source in my scene? Since there was one window in this room, I decided that it was coming from the left. So from this point onward, I needed to keep this in the back of my mind.

Fluffy clouds were a perfect first item to begin there is no exact perfect way to paint them. You get to have fun with it. Very low stress. Try to make sure that the fluffy/curviest side of the clouds were facing and highlighted from the left side, my light source. Using a very small amount of white paint on a dry bristle brush, begin to paint the clouds. Use a light touch to start and more pressure as you run out of paint so you achieve a fairly even and light application of paint. Work your brush in a circular motion to create the fluffy edges of the clouds.

Now to break out the grids. It may be necessary to subdivide the grids even further based on parts of your reference images. Lightly sketch out some large grid lines on your walls based on your layout. The primary use of the grid in my mural was to help insure I maintained all of the perspective and correct proportions of Princess Peach's castle and other large key elements. As you sketch, keep looking where parts of the reference image coincide with corners in the grids. Rinse and repeat. Make your sketches light enough where they can be easily erased if they need to be tweaked a bit.

As far as painting, besides the blue background, I used acrylic paints and just a handful of brushes. Work from the background forward, trying to not focus on many of the smaller details until the base shapes and such are in place. As I started in on the detail for the castle, I kept the light source constantly in mind. Patience and listening to some good tunes helps a lot! The castle took quite a long while, painting all of the highlights on the bricks, but it ended up adding another layer of realism that is hard to discount. Take your time and enjoy it!

Step 4: References Are Critical. Get Some Good Ones!

When drawing/painting figures and characters by hand, it's important to have good references on hand. For this mural I was fortunate that Nintendo released very good promotional images leading up to this game's launch date. But occasionally, I needed additional details that their pictures didn't provide. At the time of this project, one could post game screenshots within Miiverse (Nintendo's social media attempt for the WiiU). One additional feature of the Miiverse was that your posts and pictures were accessible through the accompanying MiiVerse website. Using this, I was able to get almost any reference image of a character or level, and view them on an iPad while working. This sped up my workflow incredibly!

If you are working on a video game based piece of art that needs in game references, don't overlook these sorts of social media capabilities of your particular console. They can prove to be invaluable.

Step 5: Foam Model Building

In Mario Kart 8, a key feature of the game is the introduction of inverted tracks. At many points in many levels, the racetrack can twist and turn all over the place. I wanted to somehow represent and capture this new and exciting feature in an unexpected way. Having the track flow up along the ceiling and suspending a big model of Mario and his Kart upside down seemed like a good idea at the time.... Let me generally run you through the build.

Making such a model could easily be pieced together using a 3D printer, but at the time, I didn't own one, so traditional sculpting was my only choice. Just as with the room, it was critical to have good references. This was a brand spanking new game at the time, and there were no physical examples of the new Kart design to go off of yet. Luckily for me, Nintendo and McDonald's just released the new vehicles in Happy Meals! So after obtaining the new Kart, a small Mario figure and taking some close up pics from the front and the side, I returned to Photoshop.

A classic drawing and sculpting technique for creating characters is to break it down into character "heads". Using the character's head as a base unit of measure, how many heads tall and heads wide is it? In Photoshop, I overlayed boxes representing Mario's head from different perspectives and was able to figure out his relative proportions. From knowing how large I wanted the entire sculpture to be, using calipers, I was able to establish a relationship between the small toy and the large model that was yet to be built.

The primary building material of both Mario and his Kart is 2-inch thick blue DOW insulation foam. (His head and hat are different and I will get to those later) This stuff was a bit challenging to track down in my area, but I eventually found it at a building supply company in a 4x8 sheet. Carefully start by cutting the foam down into the rough sizes you need with a hacksaw blade and an assortment of metal rasps and files. (WARNING: This is MESSY! :) ) Joining several pieces together was accomplished by lightly spraying each surface with 3M spray adhesive and letting it sit for a minute to tack up. This type of glue likes to eat away at the foam, which was admittedly not ideal, but very light applications it was fine. For combining larger pieces, I occasionally used wooden bamboo skewers in addition to the adhesive to help provide more support. After repeated checking with calipers, and some artistic liberties, I was finally happy with the foam variants of Mario's body and his kart.

Step 6: Now to Apply Mario's Tough Ceramic Exoskeleton...

After getting your foam model just right, it is time to get that tough ceramic-like shell going. This is accomplished by using a two part modeling compound known as Apoxie Sculpt. Apoxie Sculpt is extremely versatile and easy to work with. It has a 1-3 hour working time (depending on ambient temperatures), doesn't generate noxious fumes, and is quick to clean up just using soap and water.

Begin by mixing equal parts of part A and B together. Knead together for two minutes until thoroughly combined and a uniform color is achieved. Only retrieve and mix enough of the compound for the area you are currently working on. Press and smooth out the putty onto the surface of the foam. Having a small cup or bowl of water nearby is handy for getting your fingers wet. This helps immensely with getting this material to spread out easily. You can even employ a scraper to help smooth out larger areas.

After 24 hours, it will be completely cured and rock solid, able to be sanded, filed, carved, drilled, tapped, or painted. If you happen to sand through too far and expose the blue innards, just apply more Apoxie to the affected area and rinse/repeat. Hand sand/ power sand/ wet sand to get that finish you desire!

Step 7: Sculpting Mario's Head and Hat

This entire project was a great opportunity to do a deep dive into several materials and techniques I had never used before, DOW foam and Apoxie Sculpt included, so why stop there?! For Mario's head and hat, they were to be sculpted in clay, molded in silicone and cast in resin. The ability to possibly reuse the silicone molds in other projects was very appealing and helped me make the decision to go in this direction.

Clay Sculpting

The clay used for Mario's head and hat is called Monster Clay, which is apparently very popular with special effects houses and in the toy industry. It is an amazing sulfur free & oil based clay which means it never dries out and can be softened/melted down in a microwave over and over again. (It can even be poured into a mold itself and used to cast with, then you sculpt from there!) At room temperature it holds its shape and can be worked with your hands or any traditional sculpting tools. Using the clay, start out with big forms and refine the shapes while looking at your reference. I was utilizing a small Mario figurine as my reference, and broke out the calipers a few times during the process to check relative sizes. Just as with previous sculpting steps, it may be easier to break the entire item into measurable chunks. Before we used "heads" as the standard unit of we can use the character's eyes as the unit of measure. So on the smaller reference model, using calipers, get the dimensions of an eye. Now determine how many "eyes" wide and tall the head and face should be. Also as before, wait until the larger shapes are well established before working on smaller details. To help smooth out larger sections you can lightly brush on mineral spirits or even use a lighter/torch(I have seen this done but not tried it myself)

Step 8: Molding With Silicone

The next step in the process is to use silicone rubber to make a hopefully exact copy of Mario's head. Essentially, we are going to brush on and coat the clay head with silicone with the exception of the very top of his head where his hat would sit. Basically, we are making a giant silicone glove that can be peeled away, leaving a negative copy. There are several different approaches one could use for making such a large item, but I elected to use a technique called slush casting. This is popular for casting things that are meant to be hollow such as StormTrooper helmets! The advantage of this method is that it uses much less resin in your reproduction which makes it both lighter and cheaper than filling the mold entirely with expensive resin.

Applying the Silicone
After fully smoothing out Mario's face and identifying any big undercuts were the silicone could get snagged up, we start the silicone process. This can be very runny and messy so make sure to lay out some newspaper to catch the drippings. The specific silicone used on this project was PlatSil 71-20 from Brick in the Yard Mold Supply. This material comes in parts A and B and needs to be combined in equal parts, measured by weight. It is best to get a cheap digital scale to easily measure out your two parts accurately. After pouring equally weighted amounts in two cups, mix them together in a separate larger container. It is extremely important to thoroughly combine parts A and B, making sure to scrape the sides and bottoms of the cup to get every last bit mixed. This material has a 25 minute working time, so no need to rush. When you are convinced you have well blended silicone, using a cheap brush, apply it to the model. Make sure to use the brush and work it into any cracks and detailed areas such as around his mustache. Again, you are going to want the silicone to be applied everywhere, except on the top of his head, where the hat will cover. This will later form the opening where we will pour our resin in for slushcasting. After the first layer cures (about 4-5 hours), go ahead and add some more. In the end you want your silicone to be about 1/8" thick. Do not be concerned about how it looks at this point, as it's likely to appear quite messy such as mine above! The real magic is on the inside! The final touch with the silicone is to apply what are called registration keys to your model. These are bits of silicone that protrude from the surface that help with aligning the next step in the molding process. Several silicone suppliers have ice cube like trays to make your own keys. In the next step, we will have a seam from the top of Mario's forehead down to his chin, continuing underneath until it reaches the back of his head, where the hat will meet his hair. In this area, do not put any registration keys, but distribute them around around 2-3 inches away from each other.

Mother Mold Creation

When thinking back to the glove analogy, imagine said rubber glove is a perfect silicone mold of your hand. After removing the glove and placing it on the table, it collapses and flops over under its own weight. It does not correctly hold the shape/volume of your hand under its own weight. That is where the mother mold comes in. It is basically a rigid hand cast that is formed around the glove. The glove is attached with the registration keys into the mother mold to ensure it is in the exact right place to be able to cast the correct shape.

A hand cast comparison couldn't be closer to the truth, as the mother mold is literally plaster bandages used in casts that wrap around the silicone creating a two part rigid outer shell! Like an exoskeleton! Depending on the plaster bandages, you may need to precut the material into manageable strips. Fill a bucket of water and quickly submerge the bandage into the water. Allow the excess water to drip off of the bandage, then apply the bandage following along that imaginary seam from the forehead down underneath and up along the back of the head. Allow the bandage to overlap this seam about 1 - 1.5 inches all the way around. Continue to cover that one hemisphere of Mario's head, but remember to leave the hole along the top of the head where it will meet the hat. (I did this step with the head upside down, so it was sitting on the top of head) These bandages will begin to harden surprisingly quick, so don't dawdle! Be sure to form the bandages around the registration keys. This creates a unique point where each key exists so the silicone will be able to lock into the mold in just the right spot.

Silicone has a cool property that it only likes to stick to silicone. So you do not have to apply anything to the silicone first before the bandages, such as a release agent. Before applying the bandages to form the second half of the mother mold, apply vaseline to the bandage along the 1 - 1.5" overlap along the seam. This will insure that the two halves of the mother mold will not stick to each other and can be separated. Continue to cover the second half of the head, still remembering to leave a hole on the top of the head.

Step 9: Resin Casting

After the last bandage has dried and cured, it is time for the real fun to begin, removing the clay master sculpt, and casting the resin copy!

Begin by carefully prying apart the two halves of the mother mold. Once they are removed, you can begin to peel off the silicone like a glove. Slow down if there are areas that end up getting snagged, to minimize the damage if that occurs. The original clay sculpt should now be free! Turn the silicone mold back right side out and match up the registration keys where they lock into the mother mold. If it all goes to plan, you should get back to where you started this page, minus the giant clay Mario head inside. Using some large elastic bands or bungee cords, wrap up the mother mold so that it doesn't want to come apart.

Now for the resin. For this project I used EasyFlo 120 casting resin by Brick in the Yard Mold Supply. It has a super fast working time of only about 2 minutes. It is specifically designed for roto casting or slushcasting. Using graduated measuring cups, pour equal amounts (only a few ounces or so) of parts A and B, this time measuring by volume instead of weight with the scale. The idea is that you mix up one small batch at a time, and pour each batch inside of the silicone mold. You continue to rotate and roll the mold around, slushing it around inside. As you approach the 2 minute working time limit, the resin will start to turn into an opaque white and stop flowing. This is when you pour in another little batch and continue this process. Over time, the resin will build up to your desired thickness(between 1/16' and 1/8"). After about 25 minutes, you can can demold your duplicated Mario head! The end result is a hollow and lightweight yet very durable shell, while minimizing waste.

This entire process is just repeated to create his hat.

Step 10: Mario Paint, Sans Mouse

For the paint, I primarily used various brands of rattle cans for the primer and colors. The facial details I used enamel model paints for their durability and shininess. The circular M on the hood of the Kart was a vinyl decal I drew up and ordered. This was far simpler and less stressful than me masking and painting that by hand (which I considered and began doing until I had the decal revelation).

Step 11: LEDS

No epic project would be complete without LEDs, as it is scientifically proven that everything is better with them!

For this build, I used simple single color LED strip lighting that runs off of 12VDC. These can be easily cut to length along specific points and can be wired up via soldering or using clips. A simplified wiring diagram is available above. There was a 12 main line running down the underside of the kart. Each branch off of it is wired in parallel, to maintain 12V going to each wheel, bumper etc. The actual amount of LEDs varies based on how many fit into that spot, ranging from 3 for the bumper to around 15 for each wheel. These were all hot glued in position and the bright light was diffused by strips from a thin white cutting board mat! This is my go-to material for spreading out the light into a nice glow. The rear orange brake light was a cheap reflector with the back removed. This allowed me to slip in a few LEDs, and give it a cool effect. The DC barrel jack was plugged into a RF remote module to allow me to turn the Kart LEDs on and off and adjust the brightness along with some fun strobe/pulsating settings. The kart is mounted upside down and is plugged into an AC outlet recessed into the ceiling.

Step 12: Tires

The tires for the Kart are made of 1/4" Sintra brand plastic. This plastic can be easily machined and formed into shapes using a heat source. I took advantage of my pal's CNC and cut out the designs that I came up with based on game references. (design files available above). After cutting the treads out, I heated up water not quite to a boil to heat-form the plastic. Using cyanoacrylate (super glue) worked well at fusing the ends together forming a circle. There were some areas where they met that had larger gaps to be filled. For this, I also applied the superglue but sprinkled in some baking soda. Baking soda absorbs the glue and instantly cures it. This is a great tactic for filling in gaps or fillets and resulting in a super strong bond. Any irregularities can be easily filed off and sanded smooth. I also used some leftover Apoxie Sculpt in areas to help sculpt and finish more of the hubcap sections. Since the inside of the tires also have LEDs inside, more this white cutting board material was used to diffuse the light into a nice glow.

Step 13: Finishing Touches!

Whew! Now for some of the finishing touches! I wanted to extend the tiled/checkerboard grass out onto the ceiling to raise the wow factor even more. After scouring the internet for different solutions, I settled on 10X10" fake grass squares from Michael's craft stores. These ended up being quite expensive, even with coupons, but in the end I think it was worth it. They were easy to trim with a large pair of scissors and light enough to be stapled right up to the ceiling drywall. Trimming and fitting as I went, I tried to maintain the curve of the tapering road.

The tapering road continues until it terminates at the Mario Kart game case that the entire room was based upon, Mario Kart 8. This was the best solution I could come up with to explain where the road was going, and how Mario ended up on the ceiling.

Since the beginning, I wanted to display the chronology of the Mario Kart series on the walls in some way, and I was able to figure out how to integrate it into the logic of the room to justify their existence. The boxes are help up with the help of steel screws driven into the drywall and some magnets on the inside of the boxes. In this way, no box was harmed in the making of this nursery.

Luckily, the final step of mounting Mario was not too difficult. I had easy access to the attic above and was able to determine where the ceiling joists were located. With this information, I was able to securely attach Mario and his Kart to the ceiling using heavy duty lag bolts. The entire sculpture is surprisingly light, thanks to the majority of it being made out of insulation foam.

Much of this project was an excuse for me to try out new processes, materials and techniques, such as resin casting, silicone molding, monster clay sculpting, LED strip wiring, foam sculpting and so much more. There are many elements here that could easily be a standalone Instructable on it's own. I hope this instructable inspires you to peek a bit out of your comfort zone and take a run at a project, even a dauntingly large one such as this. Just break it down into smaller individual goals. If you end up creating anything using the information here, let me know, I would love to see it!

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