Car matting before painting. Click on the photo to enlarge.

Matting of a new or damaged car part before painting is carried out in order to improve the adhesion of the following layers that will be applied to this surface: putty, primer, paint, varnish. Matting (matting) is the application of a large number of small scratches to the car body using abrasive materials. These grooves, the depth of which should not exceed tenths of a millimeter, increase the reaction area, and therefore improve the adhesion of metal to putty, putty to primer or primer to paint.

Any car repair, as a rule, begins with matting. It is carried out manually using sandpaper or scotch-brite, and for processing large parts of a car it is very convenient to use a grinder. If you only need to reduce the gloss before painting, take the abrasive P120 - P180, and if you plan to clean up the metal - P80.

What should I pay attention to before mating the car?

1. Make sure that the respirator or mask is in good condition, as there will be a lot of dust;
2. Degrease the welds immediately before the start of car matting;
3. Stock up on developing powder: this good remedy to assess the quality of matting;
4. Choose an abrasive based on the instructions on the packaging of the material that you will then apply to the part;
5. Spruce planned local repair, process the transition zone with an abrasive with a finer grit;
6. In the matting process, use a finer sandpaper with each pass.

Matting a car with a grinder

How to use a grinder to mat the car before painting? First of all, decide what kind of machine you need for your repair work. Orbital (eccentric) machine is a universal option for the most different types grinding:

• If you need to completely clean the machine from the old paintwork;
• If it is required to process transition zones before painting individual sections of the car body;
• If you want to level the areas on which the filler (putty) has been applied.

In cases where large flat surfaces with sufficient rigidity are to be processed, a surface grinder can be used. However, remember: such a grinder cannot matte curved, curved or thin metal parts. Under pressure, they can bend and deform. Such surfaces are best sanded by hand or with a planer.

To improve the quality of matting, take note of the following recommendations:

• Check regularly for correct operation vacuum pump and hose for dust removal;
• From time to time, tap the sole of the machine so that the abrasive does not clog so quickly;
• Do not press on the machine: grinding should be carried out only under the pressure of its own weight;
• Keep the heating of the surface under precise control during matting.

Matting a car by hand or with a planer

To mat the machine by hand or with sandpaper attached to a planer, you will need an abrasive grit that is finer than recommended for machine sanding. Before starting work, make sure that the sandpaper is well fixed. Change the direction of the planer regularly during the matting process to ensure a more even finish.

When working with a planer, change direction regularly. Click on the photo to enlarge.

If you are sanding the surface by hand, use flexible sandpaper or scotch brite. These materials will help to qualitatively matte areas with complex terrain. However, in this case, do not forget about changing the trajectory of movement so that the processing is uniform.

Wet sanding or water sanding

According to this technology, matting is carried out with regular wetting of the car body before painting. For this, a wet sponge is used. Keep the water clean and change it often. After matting, wash the surface with plenty of clean water and wipe dry with a lint-free cloth.

It should be noted that polyester putties can only be sanded "dry", as the filler absorbs water well, which means it increases the risk of metal corrosion.

Removing light pebbles or smudges from varnish will be much easier if you add a little liquid soap to the water.

1. In between work, install the grinder on the sole;
2. Regularly clean the soles of STIKIT clippers with a solvent and HOOKIT clippers with a vacuum cleaner;
3. For effective lubrication, a lubricator in the compressed air line is indispensable.

Preparing a new part for painting

Most parts come from the factory with a black finish. What kind of coating is this and does it need to be cleaned off before painting the part? If this is a primer, then you can paint directly on it. However, more often than not, this coating is protective layer to protect the metal from damage during transportation and storage of parts. In this case, cleaning is mandatory.

Proper preparation of a car for painting involves not only cleaning the surfaces to be painted, but also selecting a complete set of necessary tools and paintwork materials. If you buy the wrong tool or mix the wrong components, all the effort spent on painting the car will be in vain. After painting, for sure, there will be, which will require a partial redo of the work. Or you will have to start all the work from the basics.

What tools and materials are needed to prepare the car?

Receiver - a special container designed for pumping air. It is from him that the performance of the compressor depends. A receiver with a small volume, when the compressor is turned off and on, only slightly smooths out pressure surges. A receiver with a capacity of 100 liters will provide a painting time of up to 10 - 20 minutes even with pressure drops.

2. Airbrush

Next essential tool is a pulver or spray gun. In principle, priming is practically no different from painting. Using a low-quality spray gun will lead to the fact that you have to re-clean the surface from shagreen and smudges. For a primer, a paint gun with a nozzle size of 1.3-1.5 mm is good. and the top location of the tank. For putty, a paint gun with a nozzle diameter of 1.6-2.5 is suitable.

Be sure to buy hoses specifically designed for painting. But keep in mind that a long and thin hose will cause a loss in the speed of the air passing through it and, accordingly, will provoke a decrease in pressure. A hose - a spring is not worth buying at all. It will constantly interfere, getting confused and stretched.

During compression, the air condenses the moisture it contains, and the compressor pumps oil out of the system. A jet of air carries oil and water to the surface to be painted. Therefore, they must be carefully filtered out. Coarse filtration requires 25 micron filters, fine filtration requires 5 micron filters.

Preparing a car for painting requires the purchase of high-quality spatulas. Don't be tempted to save money! The best spatulas are steel, capable of returning to their original shape after bending. You will also need plastic and rubber spatulas for filling curved surfaces.

Grinding or bar for rubbing. You can buy a ready-made bar. Or grind to the plane of a straight line wooden block. Decide for yourself what you need.

And, of course, you will need abrasive material.

• P80-120 - abrasive is designed for processing polyester, fiberglass putty, for rough cleaning of steel, for stripping old paint.
• P100-240 - abrasive is designed for processing liquid putty, for rewinding and processing polyester putties.
• p240-320 - abrasive is designed for finishing soil, putty, boundary points and contour zones.
• p400-500 - the abrasive is designed for finishing the soil directly for painting.
• p1000-1200 (wet) - the abrasive is used in transition zones, on contours, in border zones for finishing soil.
• p1500-5000 (wet) - the abrasive is intended for polishing after varnish and paint.

How to prepare a car for painting?

It is necessary to carry out a compatibility test if the machine has been covered with old paint. Soak a small cloth in 646 thinner and place on the surface. After 15 - 20 seconds, evaluate the condition of the surface.

You are lucky if the surface has not changed and remains smooth. If wrinkles appear - you have a problem! Any material applied to it, no matter varnish or primer, will wrinkle in the same way.

How to matte the surface correctly? The success of further work depends on how the surface is prepared for painting by 70%. Therefore, for grouting, you need to use the most suitable abrasives. In particular, you should not buy abrasives on a woven or conventional basis. They crumble, as they are intended only for woodworking.

The movements during grouting should be smooth, without pressure, circular. Grout over the entire surface problem area. If it clogs at the same time, then you are pressing too hard, damaging the material, or it just has not dried out yet. You can rub on wet paint or primer.

Preparing a car for painting often includes the need to remove a layer of old paint. Sometimes there are blisters on old paint. Most likely, this is due to the presence of rust. The paint may peel off due to lack of rewinding or its poor quality. When moisture gets under the paint layer, exfoliation occurs in the form of small bubbles.

With all such manifestations, it becomes necessary to remove a layer of old paint. Of course, it's incredibly hard work. But otherwise, a month after the repair, the old paint will begin to fall off in pieces. Bare metal should be coated with a special anti-corrosion primer, after filling and cleaning the surface.

Preparing a car for painting includes proper stripping working surface. old paint at the same time, it is removed with the help of an abrasive p80-180.

Work should be carried out evenly and accurately. If you started stripping p80, then when bare metal appears, go to p180.

You will spend more time using the less gritty P180 abrasive. But this will allow you to skip the work of obligatory removal of traces left by large emery. You can use a grinder or drill with a nozzle.

Proper preparation of the car for painting includes a mandatory primer. The primer will not adhere to fresh or bare metal or stay on it for long. With sandpaper p180-240, give a dull surface to the surface with uniform circular movements. There should be no shiny areas left.

Rinse the surface from dust residues using a degreaser. Wipe the entire surface with a clean cloth. Remember to use rubber gloves so you don't contaminate the cleaned areas. Sand and level the surface.

Prime the surface with an epoxy or reactive primer or, in extreme cases, with a conventional two-component primer. Dry the surface. Before painting, rub the surface with p320-500.

2. Puttying

Puttying is also the preparation of a car for painting. It helps to hide bumps and dents. But before carrying out the work, it is necessary to realistically assess the depth of the irregularities. The need for a real assessment comes from what kind of putty will need to be applied to level the surface.

• Fiberglass putty removes dents of virtually any depth.
• Soft putty according to GOST is used for dents up to 0.5 mm deep. In fact, it can withstand depths up to 1 mm.
• Finishing putty is designed to remove small scratches.

By evaluating the depth of dents and bumps, you can easily choose the putty that is suitable for your car. But there are exceptions to all rules. For example, a dent, shaped like a nail, with a radius of 8–10 mm. and 5 mm deep. able to remove and soft putty.

What if the dent is deep? Then you need a fiberglass putty. Take required amount on the spatula and add to it 2 - 4% of the hardener by weight of the putty taken. The hardener is included with the putty.

More hardener will provide faster drying. But keep in mind that this putty can become brittle. Not enough hardener will cause the putty to dry for a long time.

3. Re-priming

It is necessary to hang the part in order to have full access to it. The room must be clean. Treat this stage of work with utmost care.

Prepare the ground. In a separate container, mix the primer, hardener and thinner, after stirring the primer in a jar. The proportions necessary for proper mixing should be indicated in the instructions. Mix the primer with a clean wooden ruler or stick.

Preparing a car for painting requires cleanliness and removal of dust from the surface of the workpiece. Purchase special dust-collecting wipes. Available wet and dry. Wet ones are impregnated with an adhesive composition and are very convenient for removing dust, as they do not leave particles of fibers; when using dry ones, moisten them in a degreaser.

Pour the primer into the spray gun and test in order to adjust the torch. To apply the soil, a pressure of 3 - 4 atmospheres is required. When testing, you should get an elongated spot similar to an oval, with a height of 3 to 4 times the width.

The ratio of width and height is adjusted by a knob on the side of the gun. After you have adjusted the size of the torch, move the spray gun from side to side. Make sure that the layer is uniform and that there are no interruptions in the supply of soil. Only after that, start priming the part.

It should be primed, starting from the edge, slowly moving forward. The speed of movement is uniform, the angle of inclination is 90% to the surface of the part, towards the raw surface. Overlap each layer in half. If the result is not too even, correct when applying the second layer.

It is best if you apply the second layer along with the gloss. Then all the mistakes made will become visible. The part should be primed in no more than three layers. Allow each layer to dry for 10-15 minutes.

1. Sanding

Grind the soil with a bar with P320-500 abrasive, just like putty. Work continues to be done until they get rid of dust, risks and shagreen. If you do not get rid of them at this stage, subsequently preserved irregularities will appear after painting.

In order to check how well the car was prepared for painting, you can use black matte spray paint, followed by sanding it after drying. In places of defects, the paint will remain and if there are many defects, the work will need to be redone.

2. Surface degreasing

How to prepare a car for painting next? common solvent and compressed air remove grease and dust from the surface. In this case, you should not wipe the surface endlessly. Otherwise, you will dissolve it. To begin with, brush off the dust and, only after that, proceed to degreasing.

If you immediately start degreasing, you risk smearing the accumulated dust over the entire surface. This can lead to defects. In particular, the primer may fall off. Use this rule regularly at all stages of staining. In this case, the preparation of the car for painting will be successful!

The life time of the soil is one to two hours. Therefore, you should not prepare it in reserve. To prime the wing, you will need approximately 100-150 grams of undiluted primer.

One of the main tools, the choice of which will largely depend on the preparation of the car for painting, is the compressor. The determining parameters when buying are the performance and volume of its receiver. Productivity should exceed one and a half to two times the consumption of a paint gun. Otherwise, you will not avoid delays in work spent waiting for the compressor to pump the necessary air into the receiver.

The preparation of the car for painting does not end there. After puttying, proceed to the primer. First, it is worth cleaning the prepared surface with emery number 320 or 500 and making sure that all defects are eliminated. Otherwise, the soil will repeat every bump you leave.

How to prepare a car for painting in the presence of large dents?

On a spatula, take as much putty as you need to complete this job. The optimal amount is equal to a quarter of the spatula area. After adding the hardener, mix everything with another spatula, shifting the putty from one spatula to another several times.

Knead no longer than a minute. After 5 - 7 minutes, the putty will begin to dry. Apply it across the oblong dent and smooth along the length. As soon as lumps begin to appear in the putty, stop working.

Leveling already drying putty is unacceptable. Drying time is 25 - 30 minutes at a temperature of 20 - 25 degrees. During this time, wash the spatulas with a common solvent, after rubbing them together and, thus, removing a significant part of the putty from the surface.

Clean the dried putty with an abrasive. Take from 60 to 180. The dried putty will not clog the emery. After that, leave the surface alone for about one day, as fiberglass putty shrinks when dried.

For small irregularities, fiberglass putty is useless. Use soft. Working with it is almost the same as with fiberglass putty. Just for grouting, take emery 180 - 320.

Only liquid putty will hide small scratches. It is easiest to apply it with a sprayer, since in its characteristics it is very similar to soil. With the help of liquid putty, you can get rid of the pores that have arisen after applying the previous layers, and smooth out the risks of using an abrasive.

How to prepare a car for painting? When choosing a putty, pay attention to its performance.

• Novol, Troton - low, the cheapest putty with more or less acceptable quality.
• Car systems, Dyna do not raise any complaints, average quality.
• Body, Lesonal, Duxson, Sikkens, Shtandoks - professional quality.

The primer of the car, which is produced before painting, is a necessary operation when updating appearance cars. This process cannot be called simple and easy, but with some effort it can be done independently.

Necessary tools

The first thing to do is get the tools. Their list includes:

• spray gun;
• compressor;
• hose;
• filter.

Do not buy the most expensive devices. If painting is to be done, then a high-quality and operational primer of a car will not work without a paint sprayer, but you can use a model with an upper tank location. This will allow economical use of the composition.

On the other hand, when self-painting it is unprofitable to buy a separate spray gun for a primer, and it is not recommended to use a primer for painting - the quality of the coating will be unimportant. So you can buy one good spray gun and prime them. But in this case, it is necessary to thoroughly rinse and clean the spray gun, up to its complete disassembly and assembly, since the primer is a rougher material in comparison with paint and varnish.

When choosing a compressor, you should ask how much is its performance? It should be one and a half times more than the power of the spray gun. This condition is necessary if the receiver is small. Otherwise, (if its volume is 100 liters), the performance indicator can be ignored, since this will not cause pressure fluctuations.

For priming a car, you should purchase hoses: rubber and plastic hose-spring. This will allow you to carry the spray gun on your shoulder, which will provide convenient work. The next detail is a filter, it is permissible to use fuel from a VAZ car.

Security measures and preparatory stage

Mask with carbon filters. Click on the photo to enlarge.

After the technical component of the priming operation is ready, take care of protective equipment. Such work should be carried out in a mask with carbon filters. This will prevent inhalation of toxic primer fumes. Replacement filters are available for free sale. Saving on your own safety can end badly! In addition, it is advisable to use a respirator in which carbon filters combined with paper. Moreover, it is desirable to change the latter as often as possible - this will protect health and extend the life of the coal components.

Before you start priming, be sure to take a rag, dip it in solvent (marking 650) and place it on some inconspicuous area of ​​​​the car. After 20 seconds have passed, check if there are any "wrinkles" in this place. If they are not, then everything is in order. If they are found, be prepared that when the primer ends, and then the painting of the car, the same defects form on its surface.

Removing the old coating

To avoid such troubles, before the priming of the cars begins before the next painting, it is necessary to remove all rust and peeling paint. To remove paint, you can take sandpaper P180. The metal is cleaned with an emery cloth with a grit of 240. If this operation is not performed well enough, then the new paint will simply swell after drying.

Then wipe the car and degrease its surface, and then proceed to puttying. The choice of mixture depends on the size and depth of the dents. If it reaches 1 cm, then fiberglass putty is suitable, in extreme cases - finishing. If you buy different putty there is no possibility, then you can use the universal.

It is better to use spring spatulas. Putty is applied along the transverse lines, and leveled - along the longitudinal ones. It should dry until the surface in this area becomes hard. Then it is overwritten using P60-240 sandpaper and a special planer. In addition, after stripping, you can go through the same areas with P 400 emery (preferably with water), which levels out scratches. You also need to clean the entire surface that is supposed to be primed - you can’t do this for gloss!

Before applying the primer, the surface must be degreased, and then wiped with an antistatic cloth.

How to breed and apply soil?

The main stage, from which the primer of the car begins before body painting, consists in preparing the solution and applying it to the body. However, it does not hurt to first make sure that there are no scratches or bumps.

Soil cultivation. Click on the photo to enlarge.

It is forbidden to carry out a primer before painting in a room where there is a lot of dust and debris. In order for these works to be completed successfully, free access to each side of the car should be provided.

Prepare the composition in accordance with the proportions indicated on the package. The mixture includes primer, solvent and hardener. All components are thoroughly mixed. Do not prepare large portions, otherwise the solution will dry too quickly.

Sometimes the question arises: “Do I need to match the color of the mixture to the tone of the paint in order to prime before painting?”. The paint should be applied in an even layer, but if a chip forms, then a primer of a similar color will make such a defect invisible.

It will be easier to cover a primer of the same color with a layer of paint. Most often, a primer is used before painting. gray color. This is an excellent basis for subsequent painting activities. In certain cases, it is advisable to use white and black shades. The main condition: you need a primer of one marking.

Ground application is an operation that cannot be ignored. Why prime a part before final painting? Such preparatory operations increase the anti-corrosion resistance of the body and make it possible to obtain an ideal paintwork. The primer is a special layer on which the paint rests, for which it clings.

When the paint sprayer is filled with the composition, you should be sure of your own painting abilities. The sample needs some kind of hard surface. You can use plywood, bar. Also, do not forget to set the optimal torch power. A high-quality primer can be obtained by means of a pressure of 3-4 atmospheres.

When " practical course» on the auxiliary planes is passed, the primer of the car begins. How long this operation takes depends on the skill of the performer and the performance of the equipment. It is imperative to start work from the edge, moving towards the raw surfaces, regardless of whether a manual or electric compressor is used to primer.

The scheme for applying a primer to a car before painting is as follows: first, the composition must be laid in parallel, one strip should be halfway on the other. After the initial treatment, a 15-minute break is taken to allow the primer to dry naturally.

Experts are unanimous in the question: "Do I need a two-layer high-quality primer before painting?". This is a guarantee of a complete pre-painting treatment. Only the second layer is applied in the perpendicular direction. If you want to get a 100% flawless painting, then the primer is applied even in three layers.

It is impossible to say exactly how long the primer, which was completed before painting, dries, since it depends on the consistency of the composition, weather, humidity, and also on the thickness of the layer.

However, the instructions usually indicate how long the primer should dry under standard conditions before painting. This takes 4 to 6 hours.

The second pre-painting operation - grinding

You need to wait as long as indicated on the package in which the primer composition was located. While the primer dries for painting, prepare for the next necessary procedure for the exterior of the car. It is grinding.

The main "tool" with which the primer is sanded before the final automotive painting, - "sandery". If grinding will be done dry, then the P400 blade grade will do. When wet, it is better to use the P800 brand. To process places that are difficult to reach, it is rational to resort to the help of Scotch Brite.

Automotive painting after a preliminary two-layer primer will not be ideal if the sanding operation is neglected. The dry method is more appropriate, since water interacts negatively with the metal.

It is forbidden to sand certain types of primer with water. Then why use the wet method? To simplify the procedure and reduce the amount of dust. The choice of technology is at the discretion of the performer, but if a dry method is used, then a dust mask should be used.

Most craftsmen prefer wet sanding, as it saves material and eliminates the need for re-sanding, because it is impossible to cover scratches from P 400 sanding with paint. To remove possible defects and sagging (especially important for a puttied surface), it is required to clean it with a special planer.

The actual painting itself begins after the priming and sanding process is completed.

The final result depends on how well the master knows how to prepare the car for painting. will last long enough for a long time if everything is done correctly. However, if the rules are not followed, all the work can go down the drain. How to prepare the car for this operation so that you do not have to redo it? We will talk about this in our today's article.

Many car owners believe that the preparation process is not so important, but only a minor oversight is enough to completely and hopelessly spoil the result. Painting a car on your own or in a specialized workshop takes only 10% of the time - the rest is spent on preparatory work. All its stages can be completed in 1-2 days in garage conditions. The main thing is that everything is done strictly according to technology.

Work space preparation

Before you start preparing the car for painting, it is important to properly prepare the room where the car will then be painted. The main requirement is that it should be dry and warm. And of course, there should be no dust inside the room. It is worth remembering that any paint and varnish liquids are flammable. That is why in the room where you plan to paint the car on your own, there should not be any sources that can lead to a fire.

Necessary tools and equipment

To prepare the car for painting, you will need a certain set of equipment. machine or grinder. Also, pneumatic guns will be used in the process - with their help, liquid putty and a primer composition will be applied to the body.

To thoroughly and completely dry the body after processing, it is recommended to use infrared emitters - this equipment will not only allow you to evenly dry the car completely, but also help to significantly speed up this process.

Preparing a car for painting necessarily requires the use of putty, which means that you need to purchase all the necessary putty and primer compositions. It will be useful to have abrasive wheels for grinder. Many recommend the use of masking tapes, films and plasticine. And, of course, you need a set of tools - spatulas, planers, paint knives and whetstones.

Body Surface Cleaning

Any parts that may interfere with the painting process (and these are various moldings and other decorative parts, locks, any seals) must be dismantled. If this is not done, during the washing process, under these elements will accumulate a large number of moisture, as a result of which corrosion will begin, and the car will rot immediately after painting.

Many neglect this and consider this action optional. But experts who know how to properly prepare a car for painting recommend doing just that - to completely dismantle all unnecessary elements.

Before driving the machine into the working room, it should be thoroughly washed and wiped with a cloth. Use a rag that does not leave lint. The dirt itself will be removed only under the influence of a strong and powerful jet.

How to inspect a car

Experts willingly share with beginners the secrets of how to prepare the car for painting yourself. If you follow all the rules exactly, you can get good result. On next step the car must be carefully inspected.

The body is carefully inspected. During this process, you need to decide which parts will subsequently be repainted. Also, during the inspection, the owner will understand which elements should be leveled with putty. Next, you should decide what kind of painting will be performed - partial or full.

Paint selection

Choose suitable paint for the whole body is simple, but in the case of partial staining, everything is much more complicated. If the repainted part is even slightly different, then it looks very rough. Therefore, many workshops have computer systems that allow you to choose the right color.

At home, using one computer, the color issue cannot be solved, and therefore you need to follow a different scheme. How to prepare the car for painting and choose the right color? To do this, you need to know exactly the number of the color applied to the body in this moment(located under the hood) metal plate with shade code). What else do you need to know about how to properly prepare a car for painting? Of course, the amount of materials required for this.

To fully 4-door sedan, you need 4 kg of primers and 6 kg of enamel. If partial tinting is carried out, then for each square meter you will need 110 grams of enamel and 150 grams of primer.

And most importantly, what novice motorists should know about how to prepare a car for painting - both enamels and primers must be from the same manufacturer. Otherwise, there is a risk of rejection of the coatings.

How to protect non-paintable body parts

All elements that are not planned to be painted are carefully closed. For these purposes, professionals recommend using special stencils. They are attached to the right areas on masking tape. For places where there will be even lines, you can use a medical plaster - this is perfect solution. But often in matters of how to prepare a car for painting with your own hands, other options are also practiced - a special composition is used.

Mix 20% dextrin, 30% glycerin, add 40% chalk and 10% water. After the painting procedure, this mixture is very easily washed off with plain water. The most important thing is that this drug does not get on the stained areas.

Degreasing and grinding

Most the best remedy for this operation it is white spirit. After treatment of the body, all surfaces to be painted must be wiped dry. The next step in the task of preparing the car for painting is called abrasive processing. This is the most difficult process. There are several methods of sanding before staining. The most common are mechanical way and thermal.

Grinding Features

The mechanical method is ordinary grinding using a grit of 100. Also used special tool grit 240 for the final result.

What is the most important thing in this process? Compliance with the rules of gradation of abrasive ratings. The rule of thumb is that the grain level between the initial and next paper must be at least 100. Otherwise, there is a risk of ink sagging.

Thermal cleaning

For this processing option, a blowtorch is used. Areas that are repainted are burned out.

The paintwork will soften as a result of the heat and is very easy to remove with a brush. However this method has a drawback - if the heating is not uniform, then there is a risk of significantly violating the integrity of the metal and decorative elements. But this way you can very quickly prepare the car for painting.

Other ways to clean the body

Specialists also identify other cleaning methods - this is the use of sandblasting technology and the use of chemical substances. more often used to remove corrosion - cleaning takes place as quickly and efficiently as possible. Way chemical cleaning suitable, rather, for removing varnish on all surfaces of the body in its perfect condition. Solvents will perfectly cope with any paint and varnish coverings.

Actions after cleaning

After grinding or any other processing, another degreasing is performed. Then the body is again wiped with lint-free fabrics. After that, you can move on to the next step.

Putty

Application technology depends on the vehicle and the required task. Sometimes fiberglass or aluminum powder is additionally added to the composition. According to the task, the number of layers is also determined. Putty composition is applied to the surface strictly across the dent, while leveling it.

As soon as lumps appear in the putty mass, it is better to stop work. If the mass began to dry out, it makes no sense to touch it. The putty dries on average in 15-20 minutes.

Padding

At the final stage, primer is applied to the body. These compositions will significantly improve the quality of adhesion of the paintwork and painted parts. In addition, primers protect the metal from corrosion.

Priming is done in three stages. The first is phosphating. Then, with the help of leveling primers, small defects are removed. On last step primer gives the surface an ideal appearance.

Experts who know how to prepare a car for painting advise applying the first coat of primer in a horizontal line. In addition, each of them should overlap the previous one by 50%. The second is applied vertically and more thin layer. Each of them should dry for 10 minutes. It is not necessary to apply more than three layers. Next, the surface should dry for 2-3 hours. Then it is polished and degreased.

So, we figured out how to prepare a car for painting with our own hands in a garage.

Let's finally look at all the methods of grinding, as well as their pros and obvious cons.

To begin with, you need to decide what is wet and dry grinding.

Wet is sanding with water with special "wet" sandpapers (abrasive paper designed to be used with water).
The abrasive grain of this paper does not crumble when in contact with water, and it does not get wet. When using this sanding paper without water, it leads to a rapid clogging of its abrasive with particles of the treated surface (paint, putty, etc.).

Dry is grinding without the use of water, or, as they say, “dry” ... They use, as you might have guessed, special abrasive paper for dry grinding. When used with water, abrasive grains crumble, it soaks and becomes unsuitable for further use.

So, we already know that for each type of sanding, whether dry or wet way appropriate abrasive paper (sandpaper) must be used. And it means that it is not acceptable to use an inappropriate method of grinding (you simply will not achieve the desired effect and throw money away).

What is the difference between dry and wet sanding when preparing a car for painting?

Of course, they differ in addition to the use of special paper, and also in some nuances. For example, the grain size of the abrasive, which is marked with an alphanumeric code on modern papers.
For example:

P80 - very coarse abrasive.

P500 - smaller.

P1500 - very fine abrasive.

Despite this, the range of abrasives used for polishing car paintwork is much wider.

As far as I know, abrasives from P60 before Р4000 .

So, the dependence of the grain size of the abrasive for wet and dry grinding differs by about two times.

Let me explain with an example:

If you are sanding primer wet, you should use wet sanding paper with a grit size of approximately R800-R1000.

If you work dry, then the number of sanding paper decreases by about half, that is, you should use paper with abrasive R320-R500

Now, you should consider all the pros and cons of these grinding methods.

Wet- well, there is actually only one plus - the absence of dust. But there will be a whole garland of minuses!

1. If you grind putty and there is “bare” iron under it, then metal corrosion is guaranteed to you in the future. Since, putty has a bad property of hygroscopicity and absorbs, and also, accordingly, passes moisture through itself like a sponge.
2. It is not possible to use an orbital sander.
3. As a result, not very high-quality surface treatment.

Dry - this method is used by almost all advanced masters of the paint shop.

Despite his one main disadvantage- a large amount of dust from the workpiece, it can be successfully dealt with using vacuum cleaners, as well as dust masks on the face.

The most significant plus is the possibility of using an orbital sander, providing excellent quality treated surface.

In advanced car services have long been used combined designs vacuum cleaners and grinders, but of course it’s a little expensive for our brother, so best solution this problem is work or fresh air blown by winds or the use of protective dust masks.

Now we can sum up.

It is not recommended to use wet grinding on putty when there is “bare” (not primed) iron under it. Wet grinding is very appropriate when erasing "snot" (streaks) and other defects on varnish and paint, as well as in some cases when polishing varnish for polishing.

In other cases, I personally prefer dry sanding.

But it is up to you to decide what to apply.

Good luck in hard work!