Automotive Industry

Masking & Preparation

To begin this venture we need to clean the metal on the car. After we clean the metal, make sure it’s dry before we begin to mask the car, also do a last minute check to be sure it’s free of all dirt grease and other contaminants.

Now it’s time to mask the car, and be sure to mask all that you don’t want painted leaving no masking hanging of the car, that would get in the way of a nice paint job. The main idea of the whole thing is to produce the best quality paint possible with the given surroundings, it is preferred that you have a paint booth, but if not, make sure that the area that you use to perform the work is ultra clean and dust free.

After the car has been masked it’s time to get ready to spray the primer, once again make sure that you have cleaned your surroundings, it’s best to have some water on the floor to keep the dust down, once you are confident that the area is clean then you can begin checking the spray guns to be sure that they are clean. This is a very important step especially if they’re not your guns, dirty guns will make an ugly paint job there for wasting all of your time.

Now that you have determined that the paint guns are clean, make sure that your respirator is in good working order. Now be sure that you have all the products that you need to perform the primer job on the car. You will need primer, reducer and catalyst, you will also need strainers, stir sticks and a measuring device.

It’s best not to have to leave the paint booth during the time that your priming the car. Reducer comes in different temperatures and you need to know what temp is best for your working conditions.

The temps are as follows, their is a high temp that is designed to dry slower when it’s hot in the area where your working, high temp is good for 80 degrees and up, theirs also a mid temp, this probably the most popular temp used this is best used from 55 to 80 degrees and is designed to dry faster to make up for the colder temp, due to the fact primer will run easier in the cold weather. Now we have low temp reducer this will dry extremely slow therefore for giving the primer a better chance to run. I tell you all this in an effort to help you better understand the products that you are working with, the more you know the better armed you are for problems when they happen.

Now it’s time to enter the paint booth, and as you do pay attention to the booth filters and be sure that they sure clean also. Now get your can of primer and read the instructions on the side, usually the mix is 4:1 or 4 parts primer to one part reducer and a cap or two of catalyst and for the best results follow these instructions. After you spray the first coat of primer, you will need to wait 15 to 20 minute before you can spray the next and so on, the way I like to do this is to give the body work areas a coat or two first to build them up. The whole reason we use primer is is to give the paint a smooth surface to stick to and give the metal some protection from the elements, it’s usually a good idea to get 4 or 5 good coats on the car.

If you are really serious about the way that you want it to look the you might want to take the primer one step farther and use an etching primer before you spray the urethane or epoxy primer, an etching primer will give the top coat just a little more to stick to. Etching primer has no building qualities there for it’s not used for smoothing out waves in your work, but it will make the primer stick allot better.

I do suggest that you always use a urethane primer,and not lacquer type,as lacquer can and will shrink urethane or epoxy is recommended for best results. Epoxy is a very hard primer to sand but it’s extremely tough, and urethane is I think probably your best choice,because it’s high building and easy sanding, their are a lot of brands to choose from, I use DuPont euro myself but it’s all up to you to choose that.

Now that your card is primed, it’s time to remove the masking, and I like to do this while it’s still a little wet for the sake of ease, just be very careful about how you do it, you don’t want to screw up all that nice work, so just take it slow and easy while pulling the masking off your car.

(Sanding)

Well now the hard part is here, before you start to sand the car you’ll want to be sure that it’s been guide coated, this will make it easier for you to get an ultra smooth finish. Heres where we weed the boys form the men, if your trying to do a show finish on the car that your painting, you will want to sand it by hand with water running on it all the time.

This is the hard part,and you will have lazy people that will want to use a machine to do this, this is just a word to the wise, you have allot better control over a hand block. The best way to produce this type of high quality work is to have the best control over it that you can, offten a machine will go through your primer. If your trying to produce show quality work this would mean priming that area again I.E. more time spent, this is time that could be spent better doing other things.

Now I will explain a bit about what a guide coat is, this is it in a nut-shell. The guide coat is the step right after the car has been primed, you should do this before you pull the masking, what this in tails is misting a light coat of black paint over the primer so that you can see the low spots in your work, and no matter how good you are, you will have low spots. The idea behind this is to sand all the guide coat off with out going through to the metal on your car.

Now it’s time to start the actual sanding of the car, you need to pay close attention to detail on this part of the paint job, the better you sand it, the better it will look. I usually start with 320 grit wet paper on a medium hard block, this grit is good for getting the guide coat smoothed out, their will most likely be some small low spots that will require either spot filler or more primer. This is one of those areas where you need to pay a little attention to detail, here you will need to look at the depth of the low spot and think about it, how low is it will primer alone fill it, or will it take spot filler and then primer.

Now that you’ve finished that part it’s time to move on to the next grit of paper, I usually move to 400 grit on a medium- hard sanding block from here, you don’t want to move up to far because it can leave scratches form the previous grit of paper, so a word to the wise, don’t get in a hurry and move up to far a once this will leave seeable scratches in your work. After you’ve sanded the whole car with the 400 grit wet paper then inspect it for bare metal and guide coat still there.

The whole idea with sanding is to make the primer look the way that you want the paint to look, I sand my primer until it has a smooth shiny finish on it, as if it were the paint on the car.

You need to have a vision of how you want it to look, the one thing that you need to know is, the better you want it to look, the more you will pay for materials. Just a word of caution cheap paint materials are just exactly that cheap!!!!! and don’t use them if you want a nice paint job.

You might save some money but you will not save the agony of a crappy looking paint job. Think about this before you go and buy cheap primers and paints, do I love my car or is it just some turd to push me to work and the old ladies and back, if you love your car then don’t put cheap crap on it.

Now that I’m through with my little lecture on low quality products, it’s time to move on to the next sanding step. From 400 grit I usually move up to 600 grit wet paper, this is where I usually stop unless requested to go one more step, this is really as far as you need to go with the sanding. After you finish with the 600 grit do one final inspection of the work before cleaning it.

Well now it’s time to clean the car, for this just use soap and water, just like washing a car normally. You should blow it dry though, this being the main difference between this and a regular wash job, be sure to blow all the water out of the little cracks in the car, like the cowl area, under the hood, between the doors and in the trunk lid. Believe me this will blow water on your paint during the actual painting of the car, so be very through about this step.

If you miss some and it happens to get in your paint during the spraying process it will bubble the paint, the paint will look horrible so be sure to get all of the water out of the car first.

Now it’s to mask for the actual paint, for this refer back to the top of this page. Masking right is an art and you better take this part very serious if you want a good job.

Now that you’ve masked your car it’s time to put it in the paint booth, hopefully this is a temperature controlled booth, in any case when you roll that car in the booth all you should have to do is clean and spray, again before you put your car in the booth make sure that it’s ultra clean in there and ready to go.

Now make sure that you have everything you need in there to paint the car I.E. paint, reducer, catalyst, stir sticks, strainers and stir sticks and a measuring stick. Once again check your respirator and be sure that it’s working properly, tie your hair back and if you have a beard cover your face.

Follow all instructions on the back of the paint can to the letter or it could cause problems with the out come of your paint.

Now that you have the car in the booth, be sure to double check the masking on it, what you are looking for here is perfection and nothing less.

This means everything that if you don’t want it painted it must be masked for sure, their is no room for error here. Now you need to take a look at the supplies that you have to do the job with, and inventory them to be sure that you have everything you need to complete the job, the last thing you need is to find that you don’t have something right in the middle of painting the car. Here’s a list of what you will need for the job.

Supply List

1) Paint

2) sealer

3) reducer

4) Catalyst

5) Tack Cloths, preferably designed for clear coat

6) Measuring Cups

7) Stir Sticks

Measuring Stick

9) Strainers

10) Respirator in working order

Now I will give you a few things to think about, if your painting with metallic paints then you must pay allot attention to the settings on your paint gun. Metallic paints will tend to get lighter if the pressure goes up and darker if it goes down, your fluid flow and fan on your gun will also effect this.

Now I will give you a basic mixing chart, most paints will follow this chart.

Instructions

1) get your paint ready to pour.

2) make sure that your mixing cup is clean.

3) Get your strainer and sticks.

4) Put a strainer in the top of the measuring cup.

5) Now pay close attention to the level of paint in the cup.

Paint Mixing Table. Always be sure to read and follow the paint manufactures mixing guide lines. These mixing ratios are just a basic idea of what to do, things will change with different manufactures.

Recommended Air Pressure At Gun Head. Paint Mix Ratios. Paint Product.
25-40 PSI Mix 4:1:1 Base Coat

25-40 PSI Mix 4:1:1 Sealer

25-40 PSI Mix 4:1:1 Clear Coat

25-40 PSI Mix 2:1:1 Primer Coat

When using a paint gun, you try to achieve a certain spray pattern without any heavy or light areas, in the pattern chart above you would try to achieve pattern (A).

Now a lesson on gun angle. Their are only two angles you should ever need to use when holding a spray gun, and they are 45 and 90 degrees angles to the surface of the car that you are spraying, these angles will give you the best outcome possible, and also you should try to keep the spray gun at about 6 to 8 inches from your work. If you get much closer you will more then likely cause a run in the paint and, much more distance and you will get a dry look to your paint job, you also need to get a feel for the speed that you need to move the gun according to the air pressure and fluid flow of the gun. muscle car information Local Auto Shop Search