BUILDING THE COLOUR COATS
NICK PUTS a lot of thought into the paint mix, adjusting the amount of thinners to suit the conditions on the day – remember, there is no controlled temperature spray booth used here. To avoid orange peel effect, the paint needs to flow well as it settles on the panel, though if it is too thin there is a risk of paint runs forming. The amount of thinners may be adjusted between coats, depending how the paint is settling.
Three top coats will be applied. As Nick points out, this good thickness will allow sufficient depth for the paint surface to be repaired if lightly damaged, say, by branches when off-roading – the damaged area can be flatted back and re-polished, a process that we’ll see later, known in the trade as ‘nibbing back’.
Between each colour coat, the panels are wiped down with silicone removal fluid and then with the tack cloth, ensuring any contaminants are removed. The first coat is termed a grip coat (or half coat) because it’s a very light application, achieved by moving the spray gun relatively quickly. This thin coat adheres to the primer. After about ten minutes, the second coat (a full coat) is blown in at a higher pressure, moving the gun more slowly, and this keys into the surface of the (still relatively soft) grip coat. A gap of 15 to 20 minutes is allowed between coats, and the final coat is thinned 5 to 10 per cent, depending on the paint type, to achieve a shine.
With the three top coats on, the finish looked great. But to get this job exactly as we wanted it, Nick took the extra steps of rubbing back and polishing to achieve the sort of gentle sheen the Ninety would have had when new. After three coats of primer/filler, 1 plus flatting and wiping with a tack cloth again, the first top coat is applied with a steady continual motion. Here’s the new driver’s side door 2 after its third coat of Shire Blue. All that preparation and checking at each stage has paid off. The advantage of painting the 3 panels off the vehicle is that internal and edge details get properly coated, replicating the factory paint job. But we’re not finished yet. The 4 panels are now carefully flatted with 2000 grade wet and dry paper to remove any particles. 5 A rotary buff (not DA) is used in conjunction with 3M Fast Cut Plus cutting compound to restore the surface finish and shine. 6 After wiping away the cutting compound, a final going over with the polishing head on the DA machine achieves the optimum finish. The new rear cappings for the tub 7 were sprayed and flatted before fitting, for reasons we’ll see later. Bulkhead vent flaps also here.