How to degrease a car body before polishing, painting and washing
Content
The basis of the durability of a painted body or its individual sections is careful surface preparation. Painters know that the painting process itself takes only a few percent of the total time spent on the machine. One of the important procedures carried out repeatedly is degreasing.
Why degrease a car body
Coloring contains several stages:
- washing and preparation of metal;
- application of primary soil;
- surface leveling - puttying;
- primer for paint;
- staining;
- applying varnish.
Fat, that is, organic compounds, and not only them, can get to the surface between any of the operations. In this case, the adhesion of the next layer will be significantly worsened, the adhesion of substances at the molecular level will no longer work, most likely such coatings will very quickly begin to rise with the formation of blisters and bubbles. All work will be irreparably damaged.
To avoid such an outcome, surfaces are always degreased and dried between procedures. An exception may be the application of the next composition “wet”, that is, the previous layer not only did not have time to get dirty, but also to dry or polymerize.
What is the best way to degrease
Organic contaminants dissolve in many substances. The problem is that some of them, in turn, will require removal, and this may turn out to be even more difficult than the neutralization of primary pollution.
Therefore, the choice of a degreaser must be taken seriously, it is best to entrust such work to professionals who are well acquainted with the properties, work and consequences of using various organic solvents.
Before painting
Before each operation of applying a multi-layer paint and varnish coating (LPC), you can use different compositions.
- The bare metal of the body is subjected to primary cleaning. It undergoes mechanical cleaning to remove traces of corrosion and all kinds of organic and inorganic contaminants.
You might think that with such a removal of even the upper metal layer, there is no need for a separate degreasing. This is not true.
Machining can not only leave greasy traces, but also aggravate the situation by deeply introducing them into the surface of a pure metal that has received the required degree of graininess.
Such material needs high-quality washing. It is usually carried out in three stages - treatment with water-based detergents with surfactants and low alkalinity, treatment with simple but effective solvents, such as white spirit and the like, and then high-quality cleaning of their traces with more noble professional-type substances or antisilicone.
- Painters have a habit of going through the work area with degreasers and solvents after each procedure.
This is not always justified, but such is the experience, no one wants to ruin the work. But definitely degreasing will be required after the final preparation of the primed surface for painting.
Only a special high-quality anti-silicone flushing degreaser is used, otherwise you can ruin everything by reacting with already used consumables.
- Do not confuse washing with degreasing, although in the first case, fats are also removed, and along with all other types of pollution. But other substances are used.
For example, car shampoo cannot be considered suitable for degreasing. As well as petroleum products such as white spirit, kerosene or gasoline. After them, an even more thorough removal of organic matter will be required.
Now for coloring, complexes of materials from one manufacturer are used. They include solvents and anti-silicones, technologies are thought out to the smallest detail.
Before polishing
Polishing can be aimed at refreshing the coating by abrasive removal of its top layer or preserving a well-preserved paintwork with filling with a composition such as wax or polymers of fine pore structures and microcracks.
In both cases, degreasing will be useful, since during abrasive processing it will ensure uniform surface treatment, eliminating the formation of lumps of the processed and consumable material. The risk of additional scratches is reduced.
If the coating is protected by a decorative and preservative composition, then it should not be mixed with substances of unknown origin that accidentally got on the body, and if they adhere strongly to the paintwork, stains and craters may form, even if the body was washed with car shampoo.
A degreaser or anti-silicone will work much more effectively, and the polish will deal with the varnish or paint that it was designed to work with.
Before washing
If you consider a washing solution containing alkali, surfactants and dispersants, and this is how shampoos are arranged, as a means of removing fat, then in most cases this will be enough. But there are severe cases when no shampoo can cope.
For example, a popular case is the removal of bituminous stains, for which a special compound is sold, usually referred to as such.
In fact, this is a classic anti-silicone degreaser. An antistatic agent can also be used, which is also capable of dissolving organic matter.
Before sticking tape
Some elements of external tuning, body kits, etc., are attached to the body directly on the paint using double-sided tape.
He will be able to hold these fairly massive decorations well only if he first cleans all the places to be pasted with the same means or at least carefully wipes the surfaces with alcohol, preferably isopropyl alcohol, it does not evaporate so quickly.
How to properly degrease the surface
It all depends on the amount of pollution and the required quality of work. Sometimes the surface only needs to be refreshed, and in other cases it needs to be completely washed and cleaned.
Using a Sprayer
If degreasing is carried out more likely just in case to remove the smallest imperceptible impurities between the layers of the painting technology, which is already being worked out in clean rooms with filtered air and without touching the working area with hands, then it is enough to blow the surface with a finely sprayed composition from a spray gun or even just a manual trigger sprayer. type.
This method, with external primitiveness, works well, especially on surfaces with already created rough and rough relief, prepared for adhesion of putty or filler.
Use of napkins
Better work on a contaminated surface is carried out with special microfiber cloths that do not give the slightest lint. One of them is wetted with a solvent, the main mass of the removed substances is collected on it, and the second is dry, it completely cleans after the first.
The procedure is repeated several times with the change of napkins, the surface is blown with filtered and dried air from the paint compressor.
What to choose instead of a degreaser
It is better not to use acetone, it is an unpredictable and aggressive solvent. Like other universal solutions under different numbers, they are only suitable for rough cleaning of metals, after which additional processing will still be required.
The same can be said about white spirit, kerosene, diesel fuel and gasoline. They leave stubborn stains. So you can wash only parts heavily contaminated with oil products.
Alcohol (ethyl or isopropyl) may be a good choice. The first one does not leave stains, washes cleanly, is harmless to the paintwork, at least you can first make sure of this. But it is inconvenient for them to work, it quickly evaporates, not having time to dissolve strong and persistent pollution.
Acid, alkaline and other water-based detergents can only be used at the initial stage, this is a wash, not a grease removal.
Even if the surface looks perfectly washed, the meaning of degreasing is to completely remove even its invisible traces, which only specialized substances can handle.
