SPRAYING AND POLISHING

Mix the paint

Read the paint manufacturer’s data sheet. Use a viscosity cup or a graduated mixing stick or vessel to accurately measure the ratio of paint to thinner or hardener. If the paint’s in small tins, mix them together to get a consistent colour.

Dry run

Ideally, remove any hinged panels and spray them separately. Before you put paint in your gun, get togged up in your protective gear, connect the gun to the airline and check you can move freely and easily around the car. Form a plan of attack.

Spray final coats

Apply a wetter coat. The paint should go on glossy rather than matt as it did for the gripper coat. Adjust your speed and overlap to achieve as even a finish as possible, without runs. Cellulose may need six or more coats; other systems two or three.

Spray gun adjustment

You can control the amount of air passing over the nozzle, the volume of paint admitted and the shape of the fan. The smaller the needle/fluid tip, the lower the paint volume. Thicker paints, like primers, need larger needles/fluid tips.

Spray roof and apertures

Start by spraying the roof. Lay a wet coat down the centre and move outwards. Do the same on the opposite side. Now reduce the pressure and the size of gun’s fan and paint the door apertures, lamp apertures and all other fiddly areas.

Basic technique

The fan needs to be as large as possible and shaped more like a vertical strip than an oval. Hold the gun square to the panel at a distance of 300-400mm and move it at a consistent speed. Overlap passes, avoiding a dry or overly-wet stripe.

Apply gripper coat

If you’re using cellulose, start with a light mist coat to give the subsequent coats something to key into. This ‘dry’ coat should have a rough texture – and you should be able to see the primer beneath. Other systems need a slightly thicker gripper coat.

Final polishing

No matter how good a finish you get from the gun, it can always be improved by polishing. Flat the surface with 2000-grit wet-and-dry paper, used wet with soap to avoid clogging, to create a perfectly uniform matt finish. Finish with polishing compound, then wax. Buff it to a glass-like shine. If you’re using cellulose, leave the paint to harden for a week before flatting. For an even better cellulose finish, apply two more coats after flatting, then wait another week before flatting again and polishing.