At 02:10 AM 2/8/04 -0500, Cliff in California wrote:
>"I am working on an MGA SER. #10106 made for the USA market. Should I see if I can find nitrocelulos paint like the original or is PPG Deltron ok?"

Nitrocelulos paint is out of the dark ages. No one uses it any more, and it may not even be available.

The type of paint material used is generally irrellevent to the value of the car as a collector item. For a concours car, having all original parts may be somewhat desireable, but no one cares if the paint is cellulose or acrylic. The more important point is to use one of the original factory colors if you intend to have a show car.

If you want your car exclusively for show and not to be driven much, you might consider lacquer. With multiple coats of paint and many hours of hand finishing work, this has the abiility to produce an unbeatable show car finish. Otherwise it's not very good for a road car, because it is hard and brittle and chips easily. One prior advantage of lacquer (over enamel) was quick dry so you could wet sand and add another coat of paint in short order, or wet sand to remove dust you might get during a home garage paint job. Big disadvantage is that it is not very opaque and does not cover well, so it requires multiple coats of paint with hand finishing operations between coats.

These days you can use acrylic enamel with a catalyzing hardener, added at time of mixing just before spraying. The enamel will cover in one or two coats (probably with a slight orange peel texture). With the hardener it can set up quick enough to wet sand it as little as 12 hours after spraying (if you want to), which sort of negates one of the prior advantages of using lacquer. The hardener also gives it a glossy appearance, so if you do a good prep job and a nice spray job it may not need any followup finishing process (spray and drive). This is easy enough to use for a non-professional at home. One admonition is to be careful with the catalyzing hardener, as that stuff is definitely hazardous to your health. If you consider painting more than one or two cars in your lifetime you should use a breathing mask with forced fresh air ventilation. For one time or very rare occasional use it may be sufficient to have good room ventilation and use a carbon filter breathing mask. You can spray the acrylic enamel without using the hardener, but that takes you back to the days when you had to wait at least 30 days for it to cure before you could wet sand of wax it.

The stuff everyone is crowing about these days is base coat and clear coat enamel. The base coat is not such a bright finish, but you spray over that with clear coat which does give a very glossy finish, and may also be quite tough and chip resistant. It also does not require any hand finishing. In fact it is best not to touch the clear coat after spraying (except for later waxing) so you don't disturb the glossy appearance. This may be the paint method prefered by some professsional painters, because it gives a beautiful appearance with no hand finishing. One disadvantage is that you have to get it right the first time, because it's difficult to do touch up work on the base coart after the clear coat has been applied. If it ever needs repair work later, you basically have to sand off the clear coat over a complete panel area, then touch up the base coat, and then respray the clear coat. This can be good for a show car if done right by a pro, but it's not so good for home use by a non-professional.

There are also a number epoxy enamels available. These used to be a 50/50 mix, but a few years ago some of them became 2:1 ratio mix. These are similar to the enamel with hardener, but the hardening agents are already included in the two premixed components. These paints may not be quite as toxic as the catylizing hardener agent (or might be the same), but you should still use a carbon filter breather mask when spraying. There are also epoxy primers and seal coats available. Using the epoxy paints allows you to apply multiple pimer coats at intervals as little as 2 to 4 hours, and multiple top coats as close together as 4 to 12 hours. You might also be able to wet sand within 24 hours, and you can wax it within a few days after painting.

The epoxy paints are generally quite tough and chip resistant. The epoxy primers are quite good for sealing over a mixed variety of original paint, priners, spot fillers, etc. So if you leave the original paint on the car and do some patching and touch up work with various fillers and spot putty, then an intermediate coat of epoxy primer is good to seal it and hold it all together prior to applying the finish paint. You can also apply fillers and sanding primers over an epoxy primer coat. This makes it good for a job where the car body has been stripped to bare metal. Start by applying the epoxy primer to the bare metal for best adhearance, then do the finishing work on top of the epoxy primer coat, and maybe finish with an another coat of epoxy primer to seal over the various finishing materials before final top coat. Epoxy paints will generally be somewhat more expensive than acrylic enamel, and much more expensive than lacquer type primer and filler materials.