Repainting a car is not easy! You need a well-prepared, sanded body on which you will apply a primer, then a base and finally a finishing varnish. If you give a specialist to do this work, it will cost you a fair amount of money. So why not try repainting your car? After all, if you have a bit of a DIY soul, are patient and meticulous, this might be worth it. You don't need a lot of equipment, a few supplies… and paint! And time in front of you to do a good job!
Part 1 of 3: Prepare to paint a car
Step 1. Buy your painting
You need a primer, the final paint and the finishing varnish. The quantity to buy depends on 2 parameters: the surface to be painted (take into account the number of coats) and the yield of the product (in m2/THE). There are between 400 and 500 g of paint per square meter. We cannot recommend enough that you purchase the primer, paint and finish from the same manufacturer.
- If you intend to keep the exact color of the vehicle, know that the manufacturers have assigned codes to each of their colors: knowing the code of yours, you will just have to buy exactly that color. Allow a delay, as sellers do not have all paint references in stock!
- Calculate the quantities carefully. Once the painting started, it wouldn't be about running out of paint or finish. What you have left will be used for later touch-ups.
Step 2. Protect yourself before painting
You will need a disposable plastic full-body suit (with hood), a cartridge respirator mask, latex gloves and full-face protection goggles. Before painting, read carefully and follow the product manufacturer's precautions for use.
The cartridge mask can be rented from any equipment rental store: remember to reserve one for the said day
Step 3. Paint at the correct temperature
All these products (primer, base, finish) are to be applied within a temperature range of 20 to 30 ° C. If you are working outside, be sure the weather will be nice and the wind will be zero for the few days it takes to get to work. In a rainy region, you will have to work indoors (a well-ventilated place) and allow longer drying times between two coats.
If you respect the temperatures, you will have a perfect painting
Step 4. Wash your car thoroughly
Wash it with car shampoo, at most with dish soap. For shampoo, follow directions and for dishwashing liquid, dilute in hot water. Use either a large, clean, lint-free cloth or a large sponge. For obvious reasons, washing is always done from the upper parts to the ground. Rinse with clean water, then wipe with a clean lint-free cloth to dry the body. Change the cloth frequently.
Before repair and painting, a body must be free of its dirt, of any finishing wax and degreased. Both shampoo and dishwashing liquid have stain-removing and degreasing properties
Step 5. Sand any rusted or scratched areas
Painting over rust is out of the question. You should sandpaper these damaged areas to completely remove the rust. Start with a grain of 180, then 300. If the areas are few and far between, do it by hand, otherwise use a sander. For scratches, sand until they disappear. With that done, you will be able to sand the entire body to even out the whole thing.
In recesses and depressions, it will be necessary to sand by hand, as the sander is not able to work properly on these type of small surfaces
Step 6. Wet sand the entire car
You will use water-based sandpaper, grit 1000 or 1500 for this. To keep the paper damp all the time, you will also have a spray bottle nearby. Moisten a first area, then sand using straight back and forth movements, not circular ones. Gradually sand the whole car, the treated surface should be very smooth to the touch. Never hesitate to add water. Sometimes the primary paint is so damaged that it is better to sand down to the bare metal in order to have a surface. Otherwise a simple sanding with water to even the surface is enough.
- Sanding with a very fine grain results in a very smooth surface, but sufficiently scratched (at the microscopic level) for the primer to hold well. Never dry sand!
- You will never use too much water: sand, wet, sand …
- If you are doing the sanding by hand, the sandpaper should be mounted on a sanding block, there are special ones for cars.
Step 7. Rinse the body well
It has just been sanded and is therefore dusty. If you want the paint to hold up well, dust it off by rinsing it with water and rubbing with a lint-free cloth. If you feel any difference in the surface, sand the raised part and then rinse. When rinsing is complete, thoroughly wipe down the entire body with a paper towel or paper towel.
Rinsing is done in order to have the smoothest surface possible, free from small particles of paint, putty and sandpaper
Step 8. Mask off the parts that are not to be painted
Take car masking tape and plastic sheets (slightly extended parts). Without being exhaustive, you will have to protect the windows, the headlights, the wheels… Depending on what is to be protected, you will only put masking tape (small areas), or tape and plastic (larger areas). To slide the masking tape into the slots and other nooks, use a spatula or a thin screwdriver.
- If plastic is not available, you can use double- or triple-ply newsprint sheets.
- If you find it difficult to protect sensitive parts, go see tutorials on the Internet that explain very well how to do it.
- As you spray paint, if anything around the vehicle is likely to be painted, it should be protected with tarpaulins or plastic.
Part 2 of 3: apply a primer and a base
Step 1. To start, apply 2 coats of primer
This is the prerequisite for all subsequent layers. Read the instructions for use of the primer carefully (mixing with or without thinner, number of coats, drying times, etc.)! Fill the gun reservoir, test the nozzle on a cardboard box, then spray about 30 cm from the body in a continuous, slow motion, but not too much! Before applying the second coat, wait the time recommended by the manufacturer.
Testing the gun on cardboard or scrap wood will allow you to adjust the fog, see if the nozzle is working well, and adjust the distance
Step 2. Sand with 2000 sandpaper
This almost smooth sandpaper is used to homogenize the layers of primer. Note that between each coat of paint, you must sand in order to have an impeccable finish. No need to rub hard or for long: the primer is very easy to sand. Of course, the primer will be dry and you will be sanding with water. Pass your hand to locate any excess thickness.
Carefully remove sanding marks with a damp sponge and allow to dry thoroughly before applying any paint
Step 3. Apply the first final coat of paint (or base)
After reading the instructions for using this paint carefully, fill the tank of the gun, test it, adjust it if necessary, then paint at a distance of 30 cm, making horizontal rectilinear movements in a regular and moderately slow motion. Before applying another coat, allow the manufacturer's recommended (recoat) time to dry.
Since you have been hand-made with the primer, this final first coat shouldn't be too much of a problem or take too much time
Step 4. Apply the second final coat of paint
Mix the paint well, pour it into the tank, do the spray test, then paint in exactly the same way as for the first coat. With the coat worn, you can now clean your material while waiting for the finish to be applied.
If you feel that a third coat is necessary, go for it, having made sure to inquire about the suitability of your paint to be passable in 3 coats
Step 5. Let the paint harden well
Once again, respect the drying time recommended by the manufacturer. This time is often extended when the air is humid or cold. Don’t have fun touching your body too early, you’ll ruin everything if the paint isn’t dry enough. And everything would have to be redone!
Normally, if the job has been done well, the paint is flawless. If there was a poorly done area, it would have to be sanded locally and touched up with a special brush
Part 3 of 3: apply the topcoat
Step 1. Apply the first coat of varnish
Clean the gun reservoir well, fill it with the finishing varnish (you will have read the manufacturer's instructions beforehand), then apply it from top to bottom with horizontal movements. The gun should never stop and the sweep speed should be kept constant. Allow the time specified by the manufacturer to dry before applying the second coat.
- This finishing product is generally shiny during application, so it can be checked that the entire body will be done.
- Let the product dry for the required time and don't have fun touching it when it is still cool.
Step 2. Apply the second and final coat of varnish
You should get a glossy finish, as if the car came out of the factory. This second layer is explained in exactly the same way and in the same sense as the first. The movement of the hand with the pistol must be light, at a good distance, continuous and at regular speed, neither too fast nor too slow.
A third coat is always possible: this is the case if you have applied two really very thin coats or if the manufacturer indicates this in their instructions. Most often, 2 coats are sufficient
Step 3. Immediately remove the masking tape
Start with the painted area first and work your way up. Be careful not to touch the paint. Carefully remove any pieces of plastic or newspaper. Under no circumstances should you touch this last layer with skin, tape or plastic.
If the masking tape left some traces of adhesive, mark the spot, you will polish it later with a suitable product
Step 4. Touch up
The ideal is not to have to do it, but nothing is perfect! If in one place you had painted badly, you would have to sand, then repaint. It would be better to spot these faults before removing the tape because of the overflow. Otherwise, protect the area just around and paint.
If in the weeks and months that follow, your paint is damaged, you could do the same to fix it. In general, you will have a background of paint left
Step 5. Finally, polish the body
The finishing product is made to be polished in order to make the freshly repainted body shine. This last layer must be perfectly dry! If you don't have a polisher, there is no point in buying one just this once: this type of device is very easily rented by the day in equipment rental stores. Set the polisher to the lowest RPM, then run it without pressing down or staying too long in one spot, which may bake the finish and leave a mark.
You don't have to polish the car, but as long as you have a finish it is a good idea to use it to have a shiny car
- If you paint in cold or wet weather, drying times (undercoat, base, finish) should be extended.
- If you happen to have a few drips during application, don't panic! It would suffice to sand these excess thicknesses and repaint over them.
- The preparation and application of the various products must be done in a well ventilated area and away from any source of heat.
- In addition to the instructions for use of the products, strictly follow the precautions for use (preparation, application, equipment) given by the manufacturer.