Benjiosaur's Blog: September 2013

So here is the culmination of four months hard work and tinkering.

Why?

There were several reasons for me choosing to make an aquarium PC. Firstly, as an experiment into long term heating effects on hardware. I have had several "always on" and gaming PCs in the past, and they only seem last a year or two before malfunctioning; whether it be the graphics card, memory or HDD at fault (despite having lots of cooling fans). I am hoping that the higher specific heat capacity of oil will facilitate a more consistent temperature throughout the PC, with the internal fans and air bubbler providing a "stirring" effect. If it turns out to be reliable and stable then I will look into building a gaming version!

Finished aquarium

Secondly, as a piece of art. My man-cave is a constantly evolving beast in need of the latest gadgetry and focal points of interest to stimulate conversation.

And lastly, as a way for me to test out the difficulty in working with new materials and tools (specifically thick acrylic) so I can apply these to other projects in the future.

There are lots of other examples on YouTube that I encourage you to take a look at. There is also a commercial desktop aquarium PC that you can buy from Puget Systems that is designed for mineral oil.

9L Aquarium

The Aquarium
The main 9 litre wall mounted aquarium was purchased from a website within the UK for £100. The tank is made from glass which has been stuck together in places using what appears to be a silicone based glue. The tank is encased in an MDF frame with a gloss finish to the forward facing areas. There are two supportive glass struts at the top of the tank, on to which a glass lid is normally placed. These struts now form the main supports to the custom acrylic motherboard mounts as described below.

Inside the Aquarium
I constructed the motherboard and accessory plates from 10mm thick acrylic. This thickness is extremely rigid and will not bend when loaded with hardware. I found it very difficult to work with; a jigsaw blade generates so much heat that the acrylic reseals itself. I had to use a milling machine to cut the two rectangles in the pictures below. Drilling and tapping holes is also "interesting"; I found using rubbing alcohol whilst drilling cooled down the drill bit enough as to not melt the acrylic.

Motherboard and accessory panels

Completed motherboard panel (with some test memory)

Panel supporting USB Relay, Thermometer, TTL LED trigger and SSDs

Assembled panels ready to put inside aquarium

The Oil

5L Silicone Oil

There are hundreds of types of oil that I could have used in this project, ranging from Johnson's Baby and pure mineral oils, to transformer and immersive surgical oils. I ended up opting for Silicone-350 oil since its auto-ignition point is 400 degrees C (well above the 125 degrees C maximum CPU temperature), its viscosity remains almost constant with varying temperatures and it is relatively cheap at £39 per 5 litres from Mistral Lab Supplies.

PC Specifications

This PC has to be energy efficient since it is always left on. I also wanted to avoid having to use an external radiator and so needed to opt for a processor with low heat output; I therefore settled on an Intel Atom based motherboard.

All of the components ready for assembly

I also wanted to have everything submerged, including hard drives, and so bought two SSDs. This also serves as a redundancy if/when one decides to fail.

The specifications are as follows: