Packard Forum Index » Post-War (1946-54)

Thanks to Ehow.com, these tips for sanding.
1
Sand the top coats of paint. Chances are, your car will have many coats of paint. Using the block hand sander and a piece of 60 grit sandpaper, start sanding the car to see how many coats of paint you are working with. If the car has many coats, start with the 60 grit sandpaper on the board sander and the orbital sander. Sand the entire exterior of the car down to the last two or three coats of paint.
2
Sand the last coats of paint. Once you get down to the last few coats of paint, switch to the 120 grit sandpaper. Sand right down to the metal, keeping your sanders flat, so as not to gouge the metal of the car. You should start seeing bondo or fiberglass at this point (and if the bondo was applied much later in the car's life, you may see it sooner, depending on how many coats of paint are covering the bondo). As you are working, you can peel the bondo out of the holes in the car.
3
Take stock of the areas that are rusted out. You will need to decide if you would like to replace the entire panel or refill the hole with fiberglass. Replace the "holes" with metal--either by welding in a new panel or by cutting a piece of metal, put the metal inside the hole, and tack weld the metal in. You will then have to grind down the tack welds and go over the hole with fiberglass.
4
Don't forget to do the engine compartment, too. Most show cars have a highly detailed engine compartment, and the easiest way to keep clean is to put a coat of fresh paint on it. Make sure the metal is smooth (use a finer grit wet/dry sandpaper, if needed) and spray the entire exterior with the primer. This will keep the elements off the metal, and also lays the foundation for paint and fiberglass, bondo-glass or bondo.
5
Apply the primer. Tape off the windows, door handles and key lock cylinders. When applying the primer hold the can upright about five inches from the car and using long sweeping strokes paint the outside of the car. Make sure you do not leave any metal exposed to the elements. Let the first coat dry for about one half hour, then using the 180 grit sandpaper and your hand sanders, wet sand the entire car. Just dip the sandpaper into a bucket of water and keep doing that as it dries out. You can also turn a hose on low and hold it over the area you are sanding. You do not need that much water. A dribble is fine.
6
Dry the car off completely, then let air dry for an hour. Add the second coat of primer and use the 180 grit sandpaper and water to sand the car until smooth. Once the holes are fixed and the car is properly primed, you are ready to take your car to the painter.

STOP! DO NOT follow this advice of how to sand a car. I worked in garages and body shops for 20 years and I guarantee you, not only will you ruin your car you will make it ten times as hard for the body shop to fix it, than if you do nothing.

I wish I had time to tell you how to do this but it is harder than you think. Before you do anything go to the library and see if you can find some good books on bodywork and painting. PS most books skip over the basics and assume you already know the simple stuff but it is not so simple when you have never done it.

Basically you have to wash the car first. Then degrease with wax and grease remover if there is any danger of wax or oil being on the car. Then sand the whole thing by hand with 320 wet or dry paper. Tear the paper in half, fold the half sheet in 3 and tuck the corner between your thumb and forefinger, and sand with your hand held flat. Sand with the palm not the fingers or you will not get a flat surface.

When the car is all sanded tape it off and spray 3 thin wet coats of lacquer primer surfacer. Sand again with 100 or 120 sandpaper. Stop as soon as you go thru the primer in spots. Primer again, 3 thin wet coats. Sand with 320. Touch up minor scratches or chips with glazing putty or spot putty. Spot prime and finish sand. Now you are ready to paint.

This ignores the whole question of body work, panel replacement, dent and rust repair. That takes place between the first sanding and the first primer coats and is a story all its own.

Oh WoW, thanks Rusty for putting us all right. EHow.com not so clever then! I have a pro here to paint, but by sanding yourself, save heeps of money. Def will follow your way Rusty.

If there is one in your area, take the car to a shop that does
plastic or walnut shell media blasting (NOT sand blasting or glass bead!) and have the whole body media blasted, and while it is there, have it epoxy primered right away, immediately after being blasted. Best money we ever spent was having car bodies media blasted. Rattle cans are for patio furniture and graffiti and have no business around a car's body.

Check with your painter on what materials to use, how to do the job etc. Different brands of paint require different prep and they are coming up with new things all the time. For example lacquer primer surfacer went out of date 30 years ago for professional painters but it is what you get in spray bombs AND it is not too dangerous to use at home. Many of today's paints are very hazardous to health, working without protection is the next thing to visiting the gas chamber at Sing Sing. Even the old paints could cause serious lung damage over time, I found out the hard way.

Media blasting is very expensive and not necessary in most cases. The best primer and protection for your car, is the paint they applied at the factory. Strip a car to bare steel and it is MUCH harder to repaint not to mention an open invitation to rust.

Wow, interesting instructions for painting a car. They did leave out the details on how long you need to shake the rattle can, though. I'm not sure what ehow.com is, but their advice is worth what you paid for it.

Rusty is right that the original finish is the best protection for the vehicle, but once you start layering body work and repaints on top of that original coat your best bet may be to return to bare steel and start fresh. That, of course, should mean that the repaint include all of the proper chemicals, from etching the bare steel to the final coat of color, and be applied in a professional manner with quality equipment.

Do some research (forget the internet and find a book!)on body work as Rusty recommended and decide if such a visible part of the car's restoration is something you want to attempt. Then, get out in the garage, grab an old fender and practice, practice and practice some more. Evaluate your efforts and then decide if you want to try your skills on a car you care about. Remember though, there's nothing wrong with passing work on to a professional, especially something like auto body repair which is a skill that takes years to master.

I would be very leery about putting a modern paint system on top of old lacquer paint unless you are going for a "Wrinkle Finish".

Not all types of paint are compatible with one another. Some are ok over other types, but not the other way around.

Unless you know that car is totally rust free, then I recommend taking it to bare metal, and then using a quality catalyzed primer. NEVER use a rattle can primer as they are not catalyzed and may end up lifting under the harsh chemicals used in some of todays paint systems. Rattle cans are great for painting things like air cleaners and bracketry, put not car bodies.

I frankly would even stay away from traditional primers, and use a quality Epoxy primer as suggested by John (Mr. PB). Traditional primers are like a sponge and absorb moisture if left non-top coated. Epoxies do not suffer from that and provide excellent rust prevention.

If you are serious about taking on this kind of work yourself, do yourself a favor an look into Auto-body classes that a local community college may offer. It is time and money well spent compared to making a costly mistake with body work that then has to be stripped and redone. Modern paint and primer is very expensive. A gallon of color matched urethane paint with the activator, and reducer can easily cost between $150-$200.

A class which help you understand the basics of body work (hammer and dolly work), using fillers, differences between paint systems, mixing paints and primers with activators and reducers, and or course paint gun setup and spraying techniques.

This type of Epoxy primer ok?

eastwood.com/ew-epoxy-primer-gray-gallon-1-1.html

Or perhaps this one?

alsacorp.com/products/epoxyprimer/epoxyprimer.htm


If the final coat is a lacquer, should a lacquer
Primer be used ?