Methods and Materials
Given I had some past experience working with Carbon-fibre and the fact that the shape I need to fabricate is not a simple box or tube I decided there was only one real option for material and that was fibreglass. It would have been nicer to go all the way and use Carbon-fibre but in terms of cost it just couldn't be justified. Carbon-fibre is used for its good strength-to-weight ratio, neither of which was a priority in this project. The structure only needs to be strong enough to hold its own weight including the weight and the submarine will be sat on a desk, not needing to be moved that often, so weight was not a real issue. In any case Fibreglass still has a pretty good strength-to-weight ratio. The use of Fibreglass allows for intricate shapes to be made as long as a mould or plug can be fabricated with the features.
For the protruding details on the hull I used modelling clay as it is easy to work with and sets nice and hard with some heat, ready for painting.
So in order to lay up a Fibreglass hull a mould or plug is required to provide a surface to lay onto. A mould requires allot more effort as a plug would need to be produced then the mould produced from it, which would then need to be removed in two sections, providing two halves of the mould. This approach would provide a superior finish, however the extra effort is only really justified if the mould was going to be re-used time and time again. Given that this is a one off project I decided to lay the Fibreglass directly over a plug and dispose of the plug after.
Ideally I would have gone about making the plug using an easily shaped material such as foam or wax but I had real difficulty in sourcing such materials in such large volumes at a reasonable price. After some research I found a suitable alternative was to form the shape using modelling mesh wrapped around a skeletal structure. This would provide a foundation onto which to lay on the Fibreglass hull. To provide a bit more shaping and clean, smooth surface for the Fibreglass, I laid Mod roc over the mesh, which is basically a plaster-resin impregnated gauze.
The submarine needed to be supported whilst standing because as you would expect from a cylindrical shape it wants to roll and it’s not ideal to have all the weight concentrated along the bottom of the hull. So a base was required to support the submarine upright but also take the weight along more of the circumference. I built the stand towards the end of the build but I would recommend building a base from the start and using it during the build as I ended up with a flat spot at the bottom of the submarine from where it had been sat for long periods.
I based the base structure loosely on a typical dry dock type arrangement using wood, although I appreciate modern dry docks make use of steel work to support the ships. I used an Oak board (45 cm x 30 cm x 2 cm) to best match with the desk and it also was the least expensive in the local hardware store. I also used about 2 m of square dowel (2 cm x 2 cm) for the hull supports. I fitted felt pads between the base and desk as well as on the supports to prevent scratching of either the desk or submarine.
As the wood was fairly blonde compared to my dark oak desk I also waxed the base with a dark furniture beeswax to darken it up a little and give it a bit more character.
PC Component Mounting
Mountings were required in particular for the motherboard, water cooling system and the big case fans. The rest of the components I chose to simply lay in the hull and secure them in place using Velcro strips or Command strips. I chose to use Perspex Acrylic sheet (A3 size) as I had seen been used successfully in other custom PC builds and it seemed to be perfect for an unusual shapes needed. I went for transparent blue and cut the sheets into shape using a Dremel and bent into shape using a heat gun.
I also lined the interior with soundproofing mat, the type used for walls and floors. This provided a smoother and more attractive interior and hopefully dulled some of the noise and vibration from the PC components.
I have simply listed the main tools that were needed for the build, along what they were needed for:
- Assortment of rulers such as steel rules and measuring tapes;
- Assorted scissors, reserving a good pair for the fibre-glass fabric;
- Glue gun and plenty of glue sticks to go with it;
- Light weight cut resistant gloves for handling and shaping mesh;
- Mixing bowl to use for soaking of Mod Roc strips;
- Plenty of 600 ml mixing pots for mixing fibre-glass resin;
- Plenty of mixing stick to mix the resin mixtures;
- A syringe if mixing resin by volume or a good set weigh scales if measuring by weight;
- Plenty of disposable paint brushes for the fibre-glassing;
- Paddle roller to help push out air bubbles during fibre-glassing;
- Box of disposable gloves;
- Eye protection and face mask to use during cutting and sanding of fibre-glass;
- Electric sander or sanding block with assorted sandpaper;
- Set of files to smooth rough edges;
- Dremel, or similar, with assortment of cutting bits (Perma-Grit cutting wheels are good for composites);
- Circular cutting tool for cutting the fan holes;
- Drill with various sized drill bits;
- Heater for the colder climates (allowing suitable curing of resins).