I am always being asked what kind of paint should be used for a show quality paint job. Well, it depends on what you're going to do with the car My own preference is a basecoat/clearcoat system.It has a deep,"wet" luster, and is extremely durable and resistant to bird droppings, tree sap, insect guts, chemicals, etc. I talked about engine Restification in part two. A basecoat/clearcoat is a paint restification using modern painting technology. The concours purists who own trailer queens that are never driven on the street, and stay covered in a garage can get away with using the old single stage paints. These systems appear more like what the cars looked like when they rolled out of the assembly plants thirty years ago.They have a different finish to them, not a "wetlook" like a bc/cc system.It's your car and your decision to make. I like to make my cars as "bulletproof" as possible, including the paint. Accordingly, this will deal with applying a modern basecoat/clearcoat system on your car.
Keep in mind this is just a basic guide of techniques that we use for a show quality paint job. It requires a considerable expense of time, labor and money, but the results are exceptional. Some of our customers who have committed themselves have been awarded and recognized on a national level, including best paint awards. There is no such thing as perfect paint, but if you use a reputable product and follow the manufacturers instructions, as well as follow these guidelines,you will have show quality paint that with proper care, will last for many years.
A lot of shops will paint the body off the frame, or the front cap off the car to make it easier to paint the jamb areas, and reduce overspray. The problem with this is the definite risk of scratching or chipping the fresh paint when reassembling. I have found it easier to have the body on the frame, including the front cap. I usually remove the doors, decklid and hood to shoot the jamb areas. With proper masking, there will be no overspray problems, and these panels can be replaced with minimum risk of scratching or chipping new paint.While they are off the car, the underside of the decklid and hood can be painted.
Now that you have repaired or replaced rust damaged panels on your car, and the bodywork and metal priming is finally done. You should have two or three coats of a high solids Urethane primer such as PPG's K200 or K36. At this point a guidecoat should be sprayed on. This will help determine high or low spots when the car is "blocked".Blocking is basically sanding the panels with a long board sander to insure the panels are straight and free of waves or dings.The trick to a good show quality paint job is all in the preparation. The more the car is blocked, the straighter the panels will be. The darker the color of final paint, the more apparent the imperfections of the body will be.To me, there is nothing worse then a black car with poor body work.
Use 80 grit paper to board file(block) the panels, as this will reduce the sanding scratches in the primer. Use a "crosshatch" pattern, by sanding at a 45 degree angle, and then repeating at the opposite 45 degree angle. After you have blocked all the panels you may see some high or low spots, but they should be very minor.After you have remedied these, shoot one more good wet coat of Urethane primer and repeat the guidecoat and board filing or blocking. Be sure to let it dry enough so it won't shrink later. At this point it should be pretty close, but repeat the process if not. Remember, you want the panels to be real straight.
After the urethane primer is completely dry,(so as not to shrink any more) dust a light guidecoat over the primer, and break out the 400 grit and wetsand (by hand) the primer until it is as smooth as glass. Use a rubber sanding block and sand in one direction only. When all of the guidecoat is gone you're ready to spray the first coat of base.The primer should actually shine at this point.
The base coat/clear coat system you use should be compatible with the primer that was used, in other words it's a good idea to stick with one system. PPG or DuPont both have similar basecoat/clearcoat systems in a wide variety of colors, including codes for original 60's and 70's lacquer colors. It's always a good idea to shoot a test panel to match the color. Even with a code for your paint jobber to use, every batch mixed will be a bit different, so buy enough paint to finish the job. You don't want to have to order another quart of base, only to find out that it doesn't match the previous quart that is now on the car. This will surely ruin your day.
To help prevent "fisheyes", especially if silicone like Armorall has been used, wipe down with a wax and grease remover.Depending on your color, spray on two or three coats of base, letting each coat"tack".Now you are ready for the final coats of clear. Before spraying the clear, wipe down the dry basecoat with a tack cloth, even if you are using a state of the art downdraft paint booth.Apply three good coats of clear, allowing the proper amount of time between coats. This will allow a deep durable finish and enough clear paint to allow you to wetsand the clear coat after it is completely dry.Even the most experienced painter, in the best environment, cannot lay on a perfectly mirror like finish of paint. This comes by wetsanding and polishing. What this does is to sand down the "peaks" of paint, or "orangepeel" to a level surface. If you look closely at the brand new factory painted cars you can see a lot of orangepeel in the clearcoat.A show quality paint job cannot have this, and must be wetsanded. Start with 1000 grit wrapped around a hard rubber block. This must be done by hand, sanding in one direction only. Be sure to keep the surface wet, but clean, as even a piece of sand will put a deeper scratch in the paint than 1000 grit sandpaper. After the car is completely wetsanded with 1000m grit, go over it again with 1200 grit. This is tedious, but it will pay off later.After the 1200 grit, it will be ready for buffing with a premium compound like 3M microfine. Don't overheat the paint. Use a slow speed buffer and a good quality wool buffing pad.When buffed out, the body panels will be straight and mirror like, but it gets better. Use a premium glaze and a thick foam pad to remove any swirl marks and polish the paint. The results will be awesome.
Wait about 30 days before washing, applying wax or even putting a cover on the car. This will allow the solvents in the paint to finish evaporating and not be trapped in the paint. This could cause the paint to soften or in a worse case scenario, lift and bubble.Don't use a high pressure washer(as in pay car washes) and use a gentle automotive soap when you wash the new paint.