How to prepare and paint ABS plastic bodies

Vacuum-formed Lexan bodies set the standard for light weight and durability, but when it comes to fine detail, they simply can't match the precision of injectionmolded ABS or styrene bodies such as those like the Clod Buster's, juggernaut's and some other Tamiya's kits. Unfortunately, if you spray a thick coat of enamel paint onto the body, it's all too easy to cover up those intricate details, and since the body is painted on the outside, any gloss you achieve depends on your finishing skill- not on a crystal-clear Lexan shell.

Luckily, achieving a show-car finish with spray enamels isn't rocket science. With some patience and just a little skill, anyone can make a hard body look incredibly realistic and with a shine that looks like wet paint.

In two installments, I will cover all of the steps required to give your body a showroom shine.

BODY PREP

To paint the body parts properly, you must remove them from the parts tree. An easy way to do this is to take a sharp knife and score where the plastic tree meets the part. Then simply bend the part away from the scored line, and the part will break off easily. Don't throw away the parts tree; you will need it later.

2 Use a hobby knife or some 250-grit sandpaper to smooth the plastic where you scored it. If you remove too much, you'll be able to fix the spots with body filter later. I think it's better to remove a little too much plastic because it's easier to fill a low spot with flier and then sand it down than it is to sand out a high spot.

3 Use a fine Scotch-Brite pad or fine-grit sandpaper to tightly scuff the body's outer surface and give the primer and the fitter something to stick to.

4 Having roughened the body parts, wash them all with soap and water to remove any moldrelease agent that was used during the parts' manufacturing. Moldrelease residue will prevent the primer and filter from adhering properly to the plastic.

Give the body a quick look over for imperfections such as mold lines that are left where the halves of the mold met when the body was being formed. Remove these lines by lightly sanding with 25o-grit sandpaper, or scrape them away with a sharp X-Acto knife. Without these lines, the body will look much cleaner. I also like to lightly sand the body's edges with 6oo-grit sandpaper to remove any flash or sharp edges.

6 Fill any low spots or scratches in the body with some type of body fitter. I like to use Bondo spot putty fitter for this; It dries quickly and is easy to sand. You can apply theFILLERusing anything that's flat and somewhat rigid-an old credit card, a plastic spreader used for full-size cars, or a small piece of sheet metal. For small areas, use an old X-Acto knife blade or your finger.

When you spread the filler on the body, don't worry about how it looks. You'll sand it level later. Apply the filler in thin coats to avoid its cracking; as it dries, it will shrink, so deep scratches and holes may require more than one coat to do the job. Allow the filler to dry for at least a couple of hours before you sand it.

7 When the filler has dried ompletely, sand it lightly to level it out. I like to dry-sand with 25o-grit sandpaper and then smooth it more by wet-sanding it with 600-grit. Wet-sanding involves wetting wet-or-dry sandpaper before using it to sand. The water helps to remove the material being sanded off, and it prevents the paper from getting clogged with filler. Just sand the filler down until it's perfectly level with the surrounding area. Run a finger lightly over the area to check that everything is OK.

HOLD EVERYTHING!

Don't just lay the plastic parts on newspaper to paint them, as the paper will stick to them. Paint the main section of the body while it's sitting on a flat surface, but raise it slightly so that you'll be able to COVER the bottom with primer or paint. Prop it up on a pair of extra spray cans. I also like to place a body I'm working on on a small turntable (found in most discount stores) so I can easily paint all the sides. Alternatively, hang it up using a piece of wire.

To hold small pieces while you paint them, Cut 2-inch pieces off the parts tree and attach them to the part you are painting with a small dab of hot glue. If the part has a hole in it, you can whittle down an end of the parts tree until it can be press-fit into the part. You could also use a small wooden dowel, toothpicks, etc.; once you've attached a "handle" to a part, you can use any small clamping device to hold it for painting. Just be aware that your clamp will get painted, too!

SET UP YOUR PAINTING AREA

The area in which you paint should be warm, dry, clean, well lit and well ventilated. Before you set up the body for painting, fill a small spray bottle with water and tightly mist the area to help keep the dust down. Be sure to cover anything that you don't want to get paint on. Overspray can travel to some strange places!

PRIME IT

It's now time to prime the body. I like to use DupliColor Scratch Filter primer because it sprays well and dries fast, and it will fill any small scratches that you may have missed.