It seems that there is a mystique about how to go about getting a first class paint job, after all why else why would a decent job cost $1200 and a show quality job cost over $4000 dollars. The answer lies in the cost of labor and the experience that goes with it. If you are willing to spend a nomina of money and a lot of hard work then you can achieve a paint job that will in most cases equal that of a new car. There is a difference between a "new car look" and a "show car". But for most of us contemplating a paint job the "new car" look is what we are after.
Lesson 1 - the equipment. Some of the questions that I had before starting the job, nobody seemed to have the answer for. They didn't want to admit they didn't know so they would make up an answer. Unfortunately by shopping for answers you never know at is truth and what is a guess. Early on I decided to get an air compressor. I rationalized that with the money that I could save by doing the work myself, I could afford a compressor and make other jobs in the future easier. I settled on a Craftsman 5 horsepower oilless compressor. This type of compressor has the motor built in. It cost less, but also puts out less volume of air than a standard compressor. Although the volume of air is important it's not as critical as one is lead to believe. Air tools are all rated as to the volume that they consume, the cfm number. A tool that uses 11 cfm at 40 lbs can not keep up with a compressor that only puts out 9 cfm at 40 lbs.
When I started looking at spray guns, I realized that all of the professional type guns were rated at around 11 cfm. Obviously in order to get a good job you need a decent gun, but to use a decent gun you seem to need an industrial type compressor. After talking with a number of salesman about my predicament it became obvious that none of them had any real experience and were only spouting what was in their literature. I finally gave up and decided to borrow a neighbors spray gun. To my surprise it was one of the guns that I had been advised would not work. It was a HVLP gun requiring 11 cfm, guess what it worked perfectly. The HVLP means that it is a high volume low pressure gun. Believe me when I say that this is the only type of gun to consider. It produced no overspray to speak of and used so little paint that I felt guilty about not using what I had purchased. The savings in paint alone could have almost paid for the gun which cost $79.00 mail order.
Lesson 2 - the supplies. The amount of paint needed was another question that no one seemed to have the answer for. Obviously a bigger car will require more paint but this did not seem to be taken into consideration. Once mixed paint is non returnable, however if you run out, the next time a batch is mixed it may not match exactly. So how much do you need? I decided to go with a quart of primer, figuring that if I needed more (which I didn't) I could buy some without the matching concern. For the top coat I went with a gallon of Guards red. BIG mistake for two reasons. First the color is not a bright red but instead has an orange tint to it. And second I could have painted a van as well as my MGB. As I mentioned the HVLP gun uses very little paint! Two quarts of paint are more that enough to do a small car. After I realized that the color was not what I had expected, I bought another quart of a different shade and was able to complete car with the one quart.
Lesson 3 - the fear of buffing. Every book that I read had cautions about using a power buffer to bring out the final shine. They didn't recommend not using one but they made the consequences of using one so devastating that I decided t whole job by hand. Another big mistake. What the books failed to mention was that there are two types of buffers. A rotary buffer spins like an electric drill, an orbital buffer (like Sears, or Black and Decker) on the other hand operates as the name suggests, in an orbit and is much less aggressive. Sure it's possible to rub through the paint, but with two quarts of paint on the car it's unlikely. After spending hours of hand rubbing, polishing and waxing, I realized that I hadn't rubbed hard enough! Although I had a great shine, I also had all of the sanding scratches from the 600 grit sandpaper. In desperation I borrowed an orbital buffer from my neighbor and went at it. I was concerned because the "experts" in the books said to use no more than 2300 rpm and that the professionals use 1800 rpm. The one I had was 2500 rpm, this and the fact that I had never buffed out a paint job before was a sure recipe for disaster. After 15 minutes on the trunk lid I realized that dangers of burning the paint were greatly exaggerated. I also realized that the shine that was coming through was even greater than I was able to achieve using hand rubbing compound, hand polishing compound, a glaze and wax.
Lesson 4 - Leave the body work to an expert. I spent a full week preparing the car for the paint job. At least three full days were spent on removing small dents. After meticulously filling and sanding and filling again, there were still a few imperfections left. It's possible to get all the dings and dents out, however even the smallest one can take an amateur several hours to do correctly. Get an estimate from a small body shop to remove the dents without doing the paint work. You may be surprised how cheap it actually costs if they don't have to do the paint work. Do have them prime the repairs so that you can make sure that there are no imperfections, also be sure to mention that you will be using lacquer.
Lesson 5 - Strip the car of everything that a body shop would normally mask. Without pulling the molding, door handles etc. you'll never know what's under them waiting to ruin your paint job. Trying to mask a car can sometimes take as long as actually pulling the parts off. Be sure to diagram and label all the wires, it amazing how fast you forget how a wire was routed or attached to the body. While you are at it this is a good time to replace all the rubber seals on the car. For the extra few dollars it will increase the looks a thousand percent. In the case of the MGB take the extra time to remove the vent windows and replace the seal under them. The windows don't have to be completely removed to get at the seals so its not that big of a deal. Only remove the vent bolts and not the side window mechanism the manual tells you to do. To remove the front body side molding on the MGB it is necessary to remove the headlight buckets, this will give you access to the small nut that holds it on.
Before any sanding is done on the car wash it with a product such as Du Pont Prep-Sol. This will take off all the wax and silicone that may be on the car. Next sand the whole car down, a dual action sander with 320 grit paper works great. You should follow this up with hand sanding using 400 grit paper (optional). When hand sanding always use a block and always sand in a straight line. If you don't own a dual action sander consider buying one, they are indispensable when it come to body work or just general sanding around the house. Because of the dual action theon't leave swirl marks.
The next step will be to spray the car with a primer surfacer. This will fill imperfections and help the paint stick. After a half hour it should be dry and should be sanded again. Check with your paint dealer about using a sealer. The purpose of the sealer is to prevent bleeding of certain colors as well as minimizing swelling in sanding scratches. The actual spraying of the car will take an hour or so. It can de done in the open as long as it is not windy, and as long as you are using lacquer. Try to pick a day with low humidity as this may cause the paint to blush. Spraying the area with water to keep down the dust may help but keep in mind that it can also cause humidity under the car. A good sweeping and hose down the night before should do. Also a drop cloth will help to keep the dust down. Before you start spraying be sure the car is dust free. The final step before spraying is to wash the car down with plain water and dry it off. Then take your air hose and blout every nook and cranny on the car. Pay particular attention to nuts and bolts because this is where water hides. When you are done do it again and you'll find more water. Do it as many times as needed. When done give it a final going over with a tack rag.
The trick to getting a good spray job is adjusting the gun properly and moving the gun in a long steady motion. Adjust the gun so that you have an oval pattern and the paint is going on smoothly without any orange peal. Orange peal looks just like it sounds, you'll know it when you see it. When you start to spray, pull the trigger before you are at the actual spot you want the paint and release the trigger past the spot where you want to end. If you don't do this you will get a thicker coat at the beginning and at the end. Don't move the gun with your wrist, instead use a straight motion with your whole arm. What you want to do is avoid applying the paint in a "fanning" motion. Try to keep the gun about 6 to 10 inches from the car for the whole length of the car.
The final steps are sanding and rubbing out the car. Don't expect the car to be shiny as soon as you paint it, there is still more work to do. Depending on how much orange peal there is you may or may not have a lot of sanding to do. The longer the paint has to dry the better. If you spray it in the fall you can wait until the spring to finish. Wait at least 3 days however before sanding and buffing. Use 400 or 600 wet and dry paper and plenty of water. Hold the paper in a block and sand the whole car. A half a dozen sheets should be enough. When you rinse the car off look at it carefully. If you still see small pot marks from the orange peal then sand some more. This step determines the final outcome of your project. When you are satisfied that it is sanded completely wash the car and dry it. The next step is when you see all your work pay off.
Rubbing. This is what produces the shine. As stated above you can use a regular buffer or an orbital one. A regular buffer will give a little better shine and do it quicker but it can do damage to the paint. There I go sounding doom and gloom be sure that you don't use hand rubbing compound with a power machine and use a wool bonnet. When you are all done buffing apply a coat of glaze and wax. Put the car back together and you're done. Figure on two weeks and $150 dollars or so to do the complete job.