A clear RC shell is painted on the inside. The plastic then sits over the colour like a thick coat of lacquer, so the finish is glossy, and a roll on tarmac scratches the plastic and not the paint. It also means the job runs backwards: what you spray first is what shows on top. Follow the steps in order and a first shell will come out looking like a tenth one.
You need polycarbonate paint, not ordinary model or car paint. If that is news, read RC body paint explained first; it takes five minutes and saves a shell.
What you need
- A clear polycarbonate shell. Most arrive with window masks, a decal sheet and a protective film on the outside. Leave that film on.
- Polycarbonate spray paint: one 150ml can of your main colour for a 1:10 shell, plus white or silver to back it and black to finish.
- Curved body scissors and a body reamer.
- Masking tape if your design has more than one colour.
- Washing-up liquid, a lint-free cloth or kitchen paper, a hair dryer, and somewhere ventilated to spray.
The job, step by step
- Cut the shell out and fit it
Trim along the moulded cut line with curved scissors, then sit the clear shell on the chassis, mark the body posts and ream the holes. It is far easier while you can see through the plastic, and it keeps tools away from fresh paint. The full method is in How to cut and trim an RC body shell.
- Wash the inside
Warm water, a drop of washing-up liquid and your fingers or a soft sponge. Rinse well and dry with something that leaves no fluff. This removes the mould release left from manufacture, which is the most common reason paint flakes off later. From here on, hold the shell by its edges and keep fingers off the inside.
- Mask the windows and the design
Stick the window masks on the inside and press the edges down firmly with a fingernail. If you are spraying more than one colour, tape off everything that is not the first colour. How to mask an RC body covers tape, liquid mask and sharp lines.
- Warm and shake the can
Stand the can in warm tap water for a few minutes, then shake it for a full two minutes after the ball starts to rattle. Warm, well-mixed paint atomises finely and is much less likely to spit.
- Spray the first colour in mist coats
Hold the can 20 to 25cm from the shell and keep it moving, starting each pass before the shell and finishing after it. The first coat should be a mist you can still see through. Wait 10 to 15 minutes, then repeat. Three or four thin coats beat one heavy one every time: heavy coats run, pool in the corners and can fog the plastic.
- Work from dark to light
With more than one colour, spray the darkest first, let it dry, peel the next section of mask and spray the next colour. A light colour sprayed over the back of a dark one cannot be seen from outside; a dark one sprayed behind a light one can. The reasoning and the order for metallics and fluorescents are in Colour order and backing coats.
- Back the colour
Hold the shell up to a light. If you can see through the colour, it will look thin and patchy in the sun. Two coats of white behind pale or fluorescent colours, or silver behind metallics, make them solid. A final coat of black stops light coming through at all and hides the chassis.
- Let it cure, then peel
Leave the shell overnight if you can. Peel the window masks from the inside, then the protective film from the outside, which takes any overspray with it. That is the moment the shell goes from cloudy to glossy.
- Decals and mounting
Decals go on the outside, onto clean plastic. Then fit the shell and clip it down. See Decals, lights and finishing touches.
How long it takes
| Stage | Time |
|---|---|
| Cutting out and reaming | 30 to 45 minutes |
| Washing and drying | 15 minutes |
| Masking a simple two-colour design | 30 to 60 minutes |
| Spraying, per colour (three or four coats) | 45 to 60 minutes |
| Curing before peeling | Overnight is best |
The mistakes that catch people out
- Peeling the outer film first. It is there to catch overspray. Take it off last.
- One thick coat. It runs, takes hours to dry and can craze the plastic. Mist, wait, repeat.
- Touching the inside after washing. Finger grease shows up as a patch the paint will not grip.
- Spraying in the cold or damp. Paint blooms and dries slowly below about 15°C. Bring the shell and can indoors to warm up, spray, then bring the shell back in to dry.
- Light colours first. The darker colour that follows will show through them.
Aerosol paint is flammable and the vapour is not something to breathe. Spray outdoors or in a well-ventilated space, away from flames and pilot lights, and wear a mask rated for paint vapour if you are doing more than a quick job.
If something has gone wrong, most of it can be saved: see Fixing paint mistakes and tired shells.