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Check the hand-cut tubing in this hardline water-cooled PC build

This water-cooled gaming PC features hard PETG tubing, which was cut and bent to shape by hand, as well as some great-looking RGB lighting.

Blue hardline water-cooled PC

There’s nothing quite like a hardline water-cooling loop to make your PC build stand out, and we love what Custom PC reader Liam Betts has done with this water-cooled gaming PC. He bent and cut the PETG tubing himself by hand, using only his eyesight to measure them, and the moody blue lighting adds another touch of class.

Custom PC has been celebrating the best PC builds since 2003, and our Facebook group has over 375,000 members. We’ve seen many custom gaming PCs, from case mods to scratch builds. Here we talk to Liam about how he made this hardline water-cooled PC build, which he calls Apex Mk IV.

Custom PC: Let’s start with the initial inspiration. What made you want to build Apex MKIV, and where does the name come from?
Liam: To be honest, the initial inspiration for this build was a combination of the YouTube channels LinusTechTips and JayzTwoCents. I’ve watched both of them for years and I always loved the amazing overkill builds Jay built, and the detailed build logs Linus did at the time. They were fascinating, I was determined to build my own!

Blue hardline water-cooled PC

Custom PC: How did you go about planning the loop and measuring up?
Liam: When it came to planning the loop, my priority was having as much tubing visible at once. I drew out the loop on a picture of my PC and, once I was happy, I began to bend the tubes. I practiced a couple of times on a few offcuts and then proceeded with the real thing.

When it comes to measuring, I simply eyeballed the runs – I was pretty lucky in that respect! Once I had the bends at the correct angles, I would cut and deburr the ends and test-fit them before moving on to the next piece.

Blue hardline water-cooled PC

Custom PC: Are there any plans to expand the loop to cool the graphics card too?
Liam: in a word, yes! I plan to change out the motherboard later this year, and I will include the GPU in the loop when I do this. I’m in the stages of debating whether to upgrade the case and go with a dual-loop setup, or to just add the GPU into the current setup.

Custom PC: Did you have to modify your case in order to accommodate the water-cooling gear?
Liam: Yes, I did. I had to drill two holes in the floor of the upper compartment, so I could pass the tubes through and into the floor. The purpose for this mod was to hide the pump, which resulted in a very clean look to the fluid setup.

I started by putting the pipes in place once I’d bent them so they would touch the floor, and then proceeded to draw around the tubes, so I knew exactly where to drill the holes in the floor. After all,
I only had one chance!

I used a step drill bit to get the holes to the size I needed, then I installed two pass-through fittings from EK. These allowed me to hide the sharp edges from my drilling, which gave me the opportunity to add fittings into the floor to give the machine an even cleaner look.

Blue hardline water-cooled PC

Custom PC: That’s an enormous amount of cooling power for just a CPU. Is there an overclock and what sort of temperatures are you getting?
Liam: The CPU is an Intel Core i7-6800K. It’s getting on a bit now, but I currently have it running stably at 4.5GHz on all cores. The temperatures under load usually sit at around 50-60°C. I love the overkill cooling system – it means I can run the fans at basically silent speeds and still have fantastic temperatures.

Custom PC: What, to you, are the benefits of water cooling over air cooling?
Liam: It’s a mixture between looks and performance. A properly planned custom loop looks amazing, and the cooler temperatures mean you can get higher clock speeds, which in turn means better performance.

Custom PC: How did you go about planning the lighting?
Liam: I knew I wanted the Corsair LL-series fans in the build, as they’re simply awesome! However, I also wanted to illuminate the fluid in the system, which is why I added the RGB lighting strips (also from Corsair). You can see a video of the PC in action below:

YouTube Thumbnail

Custom PC: Did you come across any difficulties? If so, how did you solve them?
Liam: One of my challenges was getting all the hardware inside. The Cooler Master MasterCase Pro 5 has excellent support for drives, radiators, SSDs – you name it, it has space for it. However, once you’ve installed a giant 360mm radiator, it becomes difficult to fit the pump, PSU, cables and a hard drive into the basement. It’s very compact down there, and was extremely difficult to fit it all together.

Custom PC: What did you learn from the build process?
Liam: I learned that building a custom loop can be extremely time-consuming and difficult. However, it can also be one of the most fun projects you can do as a PC builder. It’s well worth it once you’ve done it.

Custom PC: Are you completely happy with the end result, or do you wish you’d done some of it differently in retrospect?
Liam: I absolutely love this rig; it gives back every time I sit down and play a game. The only bit I would have done differently is to use Mayhems Pastel Fluid instead of X1. The opaque color would have looked amazing.

Blue hardline water-cooled PC


  • CPU: Intel Core i7-6800K overclocked to 4.5GHz
  • Graphics card: Nvidia GeForce RTX 2080 Ti Founders Edition
  • Storage: 250GB Samsung 970 Evo SSD, 2TB WD Black hard drive
  • Memory: Corsair Vengeance 3000MHz DDR4
  • Motherboard: Asus ROG Strix X99 Gaming
  • PSU: Corsair HX850i
  • Case: Cooler Master MasterCase Pro 5
  • Cooling: EK Supremacy Evo RGB CPU waterblock, EK 500 RGB reservoir, Alphacool 360mm radiator, EK-XTOP SPC-60 pump, EK fittings, Mayhems X1 coolant, Corsair LL140 fans, EK PETG tubing

The PC builder

Liam Alex Betts

  • Name: Liam Alex Betts
  • Age: 19
  • Occupation: IT co-ordinator at PC Howard Ltd
  • Location: Stamford, UK
  • Main uses for PC: Gaming, video editing and general everyday use
  • Likes: I absolutely love IT – I’m currently studying for my CompTIA A+ and N+ exams
  • Dislikes: I hate mushrooms!

Hats off to Liam for making this lovely water-cooled PC build, and for cutting and bending the tubing to shape himself – it looks great, and we love the lighting. If you’re new to the world of water-cooling and want to have go yourself, then make sure you also read our full guide on how to water-cool your PC.

What do you think of this hardline water-cooled PC? Join the conversation to discuss this PC build with our 375,000+ strong member Custom PC Facebook group, where you can also submit your own PC build or gaming setup for consideration. If you want to see more outstanding custom PCs and gaming setups, check out our massive guide to the best PC builds.