A PC From the Stone Age: Building a PC Cabinet Out of Cement

Hey everyone!

I’m Ayushmaan, a B.Tech E.E.E. student, and I’ve always liked building projects that feel more like actual products than random electronics experiments.

This project started with a pretty simple idea: what if I made a PC case out of cement?

I’ve been trolled quite a few times for making things that probably didn't need to exist in the first place, and honestly, I can't even argue with that anymore. But I think this project is quite literally the final boss of that category.

A PC case made out of cement isn't exactly something anyone needs, but I really wanted to see if I could actually make one. And since I found the Concrete Contest on Instructables, it seemed like a pretty good excuse to finally build it.

So I decided to stop thinking about it and just make one.

The basic idea was to build the structure out of cardboard, reinforce it with mesh, and then cover it with cement. For the actual PC, I used some old hardware that was just lying around, so it's basically a potato PC inside a concrete case.

But hey, it works.

Materials:

1. Cardboard
2. Cement
3. Sand
4. Chicken wire mesh
5. Packing tape
6. Thin board
7. Aluminum sheet
8. Super glue

Tools:

1. Scissors
2. Cutter
3. Sandpaper
4. Cement mixing container
5. Trowel
6. Basic hand tools

Resources:

1. Fusion 360
2. Pepakura
3. Printer

I started by making the case in Fusion 360. I wanted it to look different from a regular PC cabinet, so I went with a bulky shape with a slanted top and front section.

The front has a large opening for accessing the components, while the right side has an opening that would later be covered with a grill. I also kept the inside fairly open since I still needed space for the hardware and the structure would eventually be covered with cement.

The main idea was to make the case as a series of connected surfaces rather than trying to make a complicated mould. This would make it possible to build the shape using cardboard and then use that as the base for the cement.

Once I was happy with the design, I moved on to making the template.

I used Pepakura to convert the Fusion 360 model into a 2D template. It unfolded the model into separate flat pieces that I could print out.

I arranged the pieces properly and printed them on regular paper. I then used these printed templates for making the cardboard parts.

The template was spread across multiple printed pages, so I first arranged the pages according to the design. Once everything lined up properly, I taped the pages together to make the complete template.

There were two types of lines on the template. The dashed lines were for cutting halfway through, which would let me fold the cardboard later. The straight lines were for cutting all the way through.

I then cut the template out using a paper cutter.

Once the template pieces were cut, I placed them on the cardboard and secured them with masking tape.

I made sure the template was sitting flat on the cardboard and didn't move around while I was cutting.

I used a paper cutter to cut the cardboard along the lines from the template.

For the straight lines, I cut all the way through the cardboard, while the dashed lines were cut only halfway through so the cardboard could be folded into shape.

Once all the pieces were cut, I started putting them together to form the case.

I folded the sections along the cuts I had made earlier and started joining the pieces one by one. I used super glue to hold the cardboard together and kept checking the shape as I assembled it.

The angled sections needed a little more attention because they had to line up with the surrounding pieces. After joining everything together, the cardboard formed the basic structure of the PC case.

Once the cardboard structure was ready, I added the mesh over it. The mesh would give the cement something to hold onto and make the finished shell stronger than just putting cement directly over the cardboard.

I shaped the mesh according to the different sections of the case and fitted it around the cardboard structure. I made sure it followed the shape of the case, especially around the corners and angled sections.

After covering the structure with the mesh, it was ready for the first layer of cement.

For the cement mix, I used 2 parts sand and 1 part cement. I added water slowly and mixed everything until I got a fairly dry, workable consistency.

I didn't want the mixture to be too wet because I was applying it directly over the cardboard structure. If there was too much water in the mix, the cardboard could absorb it and start losing its shape.

The slightly dry mixture also helped it stay on the surface while I was applying it instead of sliding off the mesh.

Once the mix was ready, I started applying it over the cardboard structure and the mesh. I also took my mother's help for this part since handling the cement and covering the whole structure was easier with two people.

We worked section by section, pressing the cement onto the mesh and spreading it with a trowel. The first coat was mainly about getting the entire structure covered rather than trying to make the surface perfectly smooth.

Because the mix was fairly dry, we had to press it into the mesh properly so it would stay in place. Some areas were still rough and uneven, but once the whole structure was covered, we left it to cure

After the first coat had cured, the surface was still quite rough and had a few uneven areas. So I added another layer of the same cement mixture over the case.

This time, I focused more on filling the gaps and building up the surface where it was too thin. I also tried to make the outer surface more even, since I knew I would be sanding it later.

Once the second coat was done, I left the case to cure again before moving on to the finishing work.

After the second coat had cured, I started sanding the surface. Before sanding, I wet the cement with some water, which made the sanding process easier and helped with the fine cement dust.

I went over the rough and uneven areas with sandpaper, especially around the edges and corners. I wasn't trying to make the surface perfectly smooth, but just wanted to clean it up and get rid of the bigger imperfections.

After sanding, the case had a much cleaner finish and was ready for the parts that would be mounted inside it.

Once the concrete work was done, I started working on the parts needed to mount the PC hardware.

I made the motherboard backplate from a thin board. I cut it to fit inside the case and marked the positions where the motherboard would be mounted.

The backplate gives the motherboard a flat surface to sit on, since the inside of the concrete case itself isn't suitable for directly mounting the motherboard. I kept the design simple and focused on getting the mounting points in the right places.

For the front grill, I used a piece of aluminum that I already had lying around. I cut it down to fit the opening in the front of the case.

I wanted to keep this part simple and didn't want to buy a new piece of material just for the grill. The aluminum also worked well with the concrete and gave the front a different finish.

After cutting it to size, I fitted it into the front opening of the case.

For the actual PC, I didn't buy any new hardware. I had an old motherboard lying around from an old PC, so I decided to use that for this build.

It has a 4th generation Intel i3 and a 200W power supply. I also used an SSD for storage.

It's definitely not a powerful machine. It's basically a potato PC, but the main point of this build was the cabinet, not the performance. As long as it could boot and run, it was good enough for me.

I started with the motherboard since that was the main component that needed a fixed mounting position.

I first marked the motherboard mounting holes on the backplate and made the holes. Once they were in the right places, I mounted the motherboard onto the board and placed the backplate inside the case.

After that, I fitted the power supply and the SSD into their respective positions. I kept moving things around a little to make sure everything had enough space and that the cables could reach where they needed to go.

The cable management is honestly not great. There are cables going wherever they can fit at the moment, so that's something I'll definitely clean up if I make a version 2.

Once the hardware was in place, I added a few paper models to the case as decorations.

I already had some paper models around, so I decided to use them here instead of leaving the case completely plain. They also fit nicely with the whole DIY nature of the build.

I kept them mostly as small decorative pieces around the case, without letting them get in the way of the PC components.

For the software side, I installed Linux on the PC. I went with a Debian-based distribution, since this PC doesn't need to run anything particularly demanding.

Once everything was connected, I installed the operating system on the SSD and got the PC up and running. It was nice to see the old hardware actually booting inside the new case.

And that's the finished cement PC case.

The whole thing started as a pretty unnecessary idea, and somehow I ended up with a working PC inside a piece of cement. The case isn't perfect, especially the cable management, but I like how it turned out.

I also learned that making a concrete case this way is actually quite doable. The cardboard structure made it possible to create the shape I wanted without having to make a complicated mould, and the mesh helped hold everything together while applying the cement.

There are definitely a few things I'd change in a version 2, especially the cable management and some of the finishing. But for a project that started with “what if I made a PC case out of cement?”, I'm pretty happy that it actually works.