The usual thing: you need to paint the bumper. Painted. And everything seemed to be done according to the technology: they applied and polished the filler primer, then the base, varnish ... They didn’t forget anything, they even degreased it to the conscience. But despite all the efforts, after a while the paint begins to “slide” off the bumper, like skin after excessive tanning. Who to blame? Paint manufacturer? And here it is not. We forgot that we are dealing with plastic, and it is not so simple with it.
Today you will know
Is plastic easy to paint?
The first requirement for a paint layer applied to a plastic surface is high adhesion to this surface.
But the fact is that initially after casting, the properties of the plastic surface do not at all contribute to strong adhesion to the future paintwork.
Non-polar plastic surfaces create the greatest difficulties in coloring. They have a chemically inert, non-porous surface with low surface tension - and the lower the surface energy of the plastic, the worse its "adhesion" with the applied paintwork materials.
Among all plastics, polypropylene and polyethylene have the lowest surface energy - these plastics and their modifications are considered the most difficult to color.
When painting other types of plastics, problems associated with adhesion are not so pronounced, but this does not make it easier for car repairmen, since it is polypropylene that is the most demanded and used type of plastic in the automotive industry. Almost all bumpers (and these are the main painted plastic body parts) are made from various modifications of polypropylene - usually a dark gray material that can be soldered and is inert to solvents.
Try to take a polypropylene bumper and immediately apply a paint coating on it - what happens? Knowledgeable person will answer right away: nothing good ... And indeed, the adhesive properties of the coating will be very weak. How to be?
In the automotive industry for pre-training Three main methods are most often used before applying paintwork materials: corona treatment, low-temperature plasma or gas flame treatment.
These operations are very different from conventional surface preparation methods. For example, corona discharge treatment is the effect on the treated surface of an electric discharge, which gives rise to plasma "jets". Plasma processing is carried out by exposing the plastic to a plasma flow generated by a plasma torch, and flame processing is carried out by the flame of gas burners.
The purpose of this treatment is to increase the wettability of the plastic surface, thereby improving its ability to bond with paints. For a surface to be well wetted by a liquid, the surface energy of the plastic must be higher than the surface tension of this liquid. If the surface tension of the liquid (paint) is greater, it will collect into drops instead of wetting the surface evenly. Therefore, all processing methods are aimed primarily at increasing the surface energy of the polymer.
wettability. Machined surface on the left, raw surface on the right
As a result of this processing, surface layer plastic undergoes changes: in a previously non-polar polymer, polar molecules are formed that increase the surface energy of the material. The surface at the micro level becomes rough, and its useful area of adhesion to the paint increases.
It is not necessary to explain how complex and expensive equipment is used for these processing methods. Its operation is justified only in large factories, in mass production, but for the conditions of a car service, all this is too expensive and complicated. Because of this, polypropylene has long been considered undyeable.
After brainstorming, chemists have developed alternative, more simple ways preparation of polymer surfaces - the so-called "wet" chemical methods. The most convenient and used of them is the priming of the plastic surface. A special adhesive primer applied to the surface of the plastic serves as an effective intermediary between the polymer and subsequent coatings, and adhesion in some cases may even exceed the factory one!
Now let's leave aside complex chemical formulations and get down to business.
Preparing plastic parts for painting
When starting to repair a plastic part, the first step is to determine which part we had to deal with. It could be:
- new item;
- old defective coating.
New plastic elements, in turn, can be supplied with a factory primer already applied or in a “clean” form.
If you can't figure out if the part is primed or not, rub a small area of the part with some kind of non-rough sandpaper, such as P500. If there is sanding dust, then the part is primed.
With primed details, there are at least problems, but we will talk about this later. Now we are interested in the procedure for working with "clean", unprimed plastic elements.
New unprimed part
Plastic parts are produced by injection molding, and in order to ensure that after casting the part can be correctly separated from the mold, special lubricants are used during the production process. Naturally, remaining on the surface of the plastic, they do not contribute to the adhesion of the paintwork.
There are two types of such lubricants:
- outdoor,
- internal.
External lubricants are used in a diluted form and sprayed into the mold before each new production cycle. They are not always applied, but after 3-4 times, so there is more lubrication on some parts, less on others. All of these greases can be removed in the workshop with a suitable degreaser.
Internal lubricants are introduced into the composition of the plastic itself, so there is no need for a separate spraying into the mold. Such plastics are more difficult to dye, as they are "fat" themselves. The same polypropylene refers to the representatives of fatty plastics. Internal lubricants do not dissolve and are not removed by water, and they can be removed from plastic as completely as possible only by heating.
But anyway, the first step to remove contaminants from the surface of the plastic should be washing.
Washing
The ideal solution in this case would be a pressure washer, but in the absence of one, a bucket is quite suitable. hot water with any active detergent(liquid soap, car shampoo) and some kind of brush or hard paint brush.
The part must be washed both outside and inside, and then rinsed with plenty of clean, warm water.
Evaporation
In order to be one hundred percent sure that no lubricants and dirt will interfere with the creation of strong adhesion to the future paintwork, according to the technology, an unprimed part must be heated in a chamber at a temperature of +60°C for 30-40 minutes. During this time, the lubricants that are in the pores of the plastic part will rise to the surface, where we will remove them with a cloth moistened with a degreaser. This must be done quickly, while the part has not yet had time to cool.
If the part has a rough structural surface or is heavily soiled (for example, an old bumper), it is advisable to repeat the evaporation process. And then - a second procedure with a napkin and a degreaser. For better cleaning such parts can be degreased with scotch-brite (gray).
In addition to removing grease, heating helps to reduce internal stress in the plastic, which can later cause unexpected cracking of the paintwork material. Also, heat treatment helps to identify shrinkage cavities (air inclusions) and then remove them by puttying.
To save camera time and energy, several plastic parts can be loaded and heated at the same time.
In garages, the warm-up trick can be quite difficult, so in such cases it is better to work with already primed parts.
Degreasing
Before the first grinding operation on plastic elements, whether it is preparation for priming or filling, the surface of the part must be degreased.
In addition to the obvious goals pursued by this operation, degreasing also helps to remove a significant proportion of the static charge from the part. This is important, because when applying the primer, the dust, which usually flies off the surface, will quickly stick to the “charged” plastic, as a result of which the primer will lie not on a dry, cleaned substrate, but on an already dusty one.
For degreasing, it is advisable to use only branded degreasers, preferably special ones - antistatic degreasers for plastics. They are not aggressive to plastic and perfectly remove a static charge.
It is recommended to degrease a new plastic element both from the outside and from the inside.
Matting
To prepare a new undamaged plastic element for priming, it is enough to mat it with scotch-brite or similar material. Recommended for rigid types of plastic red(Veryfine) scotch-brite, and for soft / elastic - grey(Ultrafine).
Matting can be done both dry and with water. If a matting paste is used, after it it is necessary to thoroughly rinse the part with plenty of warm water - paste residues can interfere with normal adhesion with paintwork materials, which we have successfully fought so far.
If there are minor damages on the surface during transportation (for example, shallow scratches), then they are polished with a grinder and abrasive wheels P320-P400-P500, after which the rest of the surface is treated with scotch-brite.
After grinding, the part is degreased again.
Padding
Once and for all get rid of problems with the adhesion of paints and varnishes on plastic surfaces One simple rule will help. As a primary primer on clean (unprimed) plastic, a special adhesive primer for plastic (aka primer, adhesion activator) should be used.
As a rule, such soil is very liquid material, made on the basis of polyolefin resins, often transparent with small additions of metallic particles - to control application. The layer thickness is minimal - only a few microns. Most of these materials are one-component, although 2K primers are also available.
Such primers have been developed primarily for use on plastics of the polypropylene group (PP / EPDM, PPC, PPE, PPO, etc.), but most of them can also be used on other types of plastics: ABS, PA, PC, PVC, PRO, PUR, fiberglass (GFK, BMC, SMC), etc. Modern primers have practically no restrictions on the chemical composition of plastics, with the exception, perhaps, of pure polyethylene (PE).
Plastic body parts (fenders, hoods, bumpers, etc.) are produced in a modified form to improve their properties and guarantee coloring, which means they can be painted, despite the fact that they are sometimes labeled as PP and PE. In fact, unmodified polyethylenes (PE) and polypropylenes (PP) can only be dyed after being activated by a gas flame or corona. Otherwise, adhesion will be very weak! Made from "pure" PP or PE various cisterns and other expansion tanks, disposable tableware etc.
Primers are available both in jars and aerosol cans. Spray primer is very handy for minor repairs, for example, when small areas were sanded down to plastic when sanding a bumper. The release form in a can allows you not to waste time preparing the soil for spraying from the spray gun and its subsequent washing. Remember to shake the can vigorously before use.
The primer is applied in one or two thin even layers with a wide jet over the entire surface of the part. Be careful when applying! Since the material is very liquid, one should be wary of the possible excess of the applied layer and soil runoff (it is most possible at the ends and stiffeners, along the perimeter of the part). A significant excess of the layer thickness can cause a deterioration in the adhesion of the entire coating and "compression" of subsequent applied layers.
It should also be taken into account that after application, the primer changes the chemical state of the substrate only for a certain time, during which it should be applied next material. Therefore, to achieve the best adhesion, it is necessary to start applying the subsequent layers of the system after 15-20 minutes.
Most primers can be directly overcoated with the topcoat, but to increase protection against chipping, it is recommended to additionally apply an acrylic leveling primer to the surface, remembering to add the required amount of plasticizer to it, depending on the hardness of the plastic.
Just remember that such thick layers of primer-filler, as in the repair of metal parts, cannot be applied. Plastic is an elastic material, and an excessively thick layer may simply not withstand mechanical stress and the consequences of deformation.
After applying the filler - painting. Either "", if the soil allows it, or with.
By the way, in addition to the classic primers, in many lines there are also universal primers for plastics, combining the properties of both a primer and a filler with a plasticizer. They have good adhesion to plastic and at the same time allow you to even out minor irregularities (for example, small scratches from abrasive grinding). Such primers do not require prior application of an adhesion promoter and thus in some cases save a whole layer and operation.
About epoxy primer
So, drawing an analogy with anti-corrosion primers applied to metal, and acting as an effective mediator between the surface and subsequent coatings, appropriate adhesive primers are used on plastic for this purpose.
Since we mentioned primers for metal, I would like to speculate a little more on this subject and recall about.
Those who have worked with this material know what excellent adhesive properties it has. And despite its direct purpose for applying to metal, an epoxy-based primer could well be used as a primary material on many types of plastics. However, there are still limitations in this not entirely logical action. The fact is that epoxy primer does not have sufficient elasticity, and a plasticizer is not used with it.
However, if you have to deal with the repair of hard plastics such as fiberglass or carbon fiber racing cars (Carbon fibre), the use of epoxy on these types of plastics is not only allowed, but recommended. You can be sure: its adhesion to the surface will be excellent!
New primed part
Practice shows that the quality applied to plastic parts factory primer coat can vary greatly from case to case. There are usually no problems with original parts, but the primer on parts of dubious origin can easily have poor adhesion or increased sensitivity to solvents. It is not difficult to check this: take a napkin or rag soaked in solvent and attach it to the part for a minute or two.
If the coating has softened, it must either be completely removed mechanically (P150-P240-P320), or a layer of insulating primer should be applied, having previously treated the part with gray scotch-brite, and then painted.
If a satisfactory test result is obtained, conventional technology is applied. The part is degreased, matted, degreased again and painted. For matting, you can use:
- gray scotch-bright (ultrafine);
- abrasive material gradation P400-P500 (when working with a dry grinder);
- material gradation P800-P1000 (when working manually "wet");
Before starting any work, the part must be thoroughly washed and dried, and before the matting operation, as well as after it, it must be degreased.
Damaged plastic element
Under the repair of a damaged plastic part, we mean the repair various scratches, dents, chips and similar damage to the paint layer. We will talk about more complex cases of restoring plastic parts, such as cracks or significant deformations, in a separate article.
Before starting work, a standard set of procedures is performed: the part is washed, dried and degreased. The next step is to prepare the damaged areas for puttying.
grinding
Before proceeding with the filling of damages on the plastic part, the paintwork should be removed from the surface of the defective areas - this will avoid such defects as peeling and settling of the putty.
An eccentric sander is suitable for sanding damaged areas and abrasive wheel gradation P180.
When grinding, try to avoid excessive pressure and high speeds. Remember that thermoplastics begin to melt when heated.
Puttying
Hard-to-reach places are treated with an abrasive sponge (P600-P800) and / or gray scotch brite (Ultrafine).
Painting of plastic parts
It makes no sense to dwell on this stage in detail, since the primed surfaces of plastic and metal are absolutely identical. Just don't forget about adding paint or clear varnish to 2K required amount plasticizer.
But on plasticizers and some other additives it is worth dwelling in more detail.
plasticizers
Adding a plasticizer to standard 2K acrylic primers, enamels, and varnishes is necessary for two reasons. Firstly, the additive makes the material elastic, which means that the coating will not crack when the plastic is deformed.
Secondly, when the temperature of the plastic surface changes, the paintwork will expand and contract in the same way as it.
Have you often seen microcracks on the paint surface of bumpers in places that seem to be completely unaffected by deformation? This is a consequence of the thermal expansion of the material and the absence of repair materials plasticizer.
The coefficient of thermal expansion of plastics is much higher than that of metal. Covering enamels and especially primers, whose coefficient of expansion is extremely low, simply cannot withstand large temperature changes without a plasticizer and crack.
An important role is played by the amount of added plasticizer, which is always indicated in the technical documentation for the product. This amount depends on the stiffness of the plastic - the stiffer the plastic, the less plasticizer is added. Conversely, the softer/flexible the plastic, the more.
For example, for painting an elastic bumper, this amount can be 30%, for a soft polyurethane lining - 50%. When coloring fiberglass, the addition of a plasticizer is usually not required.
No plasticizer is added to base enamels!
Mixing sequence
When adding a plasticizer, it is recommended to prepare the material in a certain sequence: first, a plasticizer is added to the base material, whether it be primer, enamel or varnish, and then a standard amount of hardener and, if necessary, thinner are added to the total volume of the resulting mixture.
This sequence is due to the fact that the plasticizer also contains a binder that requires polymerization. And if a hardener is first added to the material, and then a plasticizer, this can adversely affect the drying, strength and performance characteristics of the coating.
Matting and structural additives
Well-polished lacquer or topcoat has smooth surface and great gloss. This is very good.
However, these qualities are not always in demand. The fact is that on some cars, plastic elements may not look as shiny as the rest of the body. Moreover, they may have some texture. Often colored like this plastic bumpers SUVs, many Mercedes plastic linings have such a grainy, as it were, “rough” surface.
Such a surface can be imitated by special structural additives to 2K top coats and clear varnishes. As a rule, they are produced in two types: rough(grob) and thin(fein). As a result of the application of a structural additive, the paint surface becomes matte and acquires the desired degree of roughness.
When adding structural additives, additional addition of a plasticizer is usually not required.
There are also additives that do not change the structure of the surface, but are intended solely to lower the gloss level of the coating. Depending on the amount added, the degree of gloss can be varied over a very wide range, allowing you to achieve a different matte effect - from silky to completely matt.
Drying
For drying painted plastic, it is often recommended to use natural drying or a temperature not exceeding 40-45 ° C. It is worth recognizing that such "reinsurance" is not without meaning. Plastic is better to dry longer than metal, but at a lower temperature. It should also be taken into account that the introduced plasticizers and other additives increase the drying time.
But still, with the right approach to repair, which we discussed in such detail above, more intense heating at 60 ° C will not cause any problems. And the quality of the coating will only benefit from this.
Be careful with IR drying as you can't control the surface temperature of the plastic parts.
About adhesion after painting
Another feature of plastic is that adhesion on it does not reach its normal parameters immediately, but after a certain time. So don't be surprised if an accidental scratch on a freshly painted bumper leads to further "peeling off" of the coating. It will take a few days and adhesion will return to normal.
For the same reasons, try not to wash a freshly painted plastic element under high pressure within 3-4 weeks after repair.
utility
Full-size versions of images will open in a new window when you click on the image!
How to repair plastic parts
Designations of the most common plastics
Classification of plastics depending on hardness
The main modifications of polypropylene and their areas of application in the car
There are situations when motorists and owners of houses or apartments decide to change the usual interior and color of a room or car, as a result of which they face interest Ask: how to paint plastic and what materials can be used for this?
We paint plastic
As a rule, the technology for performing painting work for any surface remains the same. But apart from general requirements, there are also some subtleties, without which it is simply impossible to perform a high-quality finish. That is why it is worth taking such additional information into service.
Varieties of paints for pvc products
We paint plastic
Today, a huge variety of paints is presented on the market of paints and varnishes, which can be used to cover PVC structures with high quality. They can be either in the form of an aerosol and spray, or in the form of a familiar paint for application with a brush or roller, which can be either matte or glossy or mother-of-pearl.
Specifications for paints suitable for plastics are shown in the table.
- Maraplan is a great example for pvc construction work.
Finishing work with such paint is performed using a roller, sponge, brush or sprayer. If such paint on plastic is applied at a temperature of 20 ° C, then after 20 minutes you can start applying a second layer, and after another 4-5 hours the product will be absolutely ready for use. Maraplan paint is very resistant to ultraviolet rays, and is also resistant to mechanical damage. But, it is better not to subject the film to mechanical overload until the coating is completely dry.
- Rainbow-180 is an absolutely white glossy coating for pvc sheets.
This plastic paint is used to decorate windows, window sills, skirting boards and other hard plastics, which can be used both for exterior and for interior finishes. Except pvc, aerosol is suitable and various surfaces, as well as putty and wood. You can work with such paint at 15-75 ° C, and the next layer can be applied after 1-2 hours. This paint is great for outdoor decorations.
- Snezhka is an acrylic-based enamel for decorative framing of hard PVC and other materials.
According to the advice experienced craftsmen, it is better to apply such a coating in 2 layers. After applying the paint, the surface of the plastic will be matte after 5-15 hours, and this coating can be used for both exterior and interior work.
- Acmelight is a coating that can glow blue or green in a dark room.
We paint plastic with our own hands
This paint is widely used for PVC, ABS, polystyrene and polypropylene. It has a high level of strength and weather resistance. Such paint has proven itself in the restoration of pots, furniture, souvenirs, window and door blocks using a spray or dipping method from 1 to 3 layers, as indicated in the instructions for use of the material. Before starting painting work, as well as in the process of their implementation, the paint must be thoroughly mixed all the time, because the additives are prone to settling, and the time for drying the finish varies within 2-4 hours.
- Gamma - acrylic paint presented as an aerosol.
In a palette like this finishing material There are about 25 shades that are applied to plastic, wood and steel, and it is also great as a graffiti spray. Obtained in this way decorative coating will be weather resistant, have a deep color and a muted sheen. For achievement best result it is better to choose a white base (if we are talking about a fluorescent version, this requirement is mandatory). Sometimes it is necessary to adjust the material in 2 layers to increase the contrast and enhance the color, but it is allowed to reapply the material only after 30 minutes, so that the bottom coating has time to dry properly.
It is also worth highlighting a separate category of paints, which include chromium. Chrome is also referred to as " mirror paint» is most appropriate in mechanical engineering. To apply chromium to the surface of the product, both an aerosol and a galvanic method are used, the difference will be almost imperceptible.
Today, finishes such as chrome (especially in the form of an aerosol) are gaining more and more popularity. Chrome, due to its mirror-like features, fascinates the eye of passers-by, which is why mottos and motorists love to use it.
In addition to high strength, chrome withstands high temperature changes, and it does not matter at all what is used for applying an aerosol or painting was done at the factory.
Chrome can have a gold or silver color, which can also be an interesting detail when decorating the interior of your apartment. In addition, chromium has excellent physical and chemical properties and an affordable price.
How is painting done?
Before starting painting work, the plastic must be pre-cleaned and dried, because it is allowed to paint it only when good level adhesion that can only be achieved on a degreased and cleaned base.
To prepare the surface and clean it, in no case do not use the usual solvents or the familiar white spirit for a long time. Today, the market offers specialized formulations for cleaning plastic in a wide range.
Please note that not every plastic needs a primer, and sometimes it happens with accuracy, yes, on the contrary, it is impossible to do without it. To understand how to act in a particular situation, there are 2 simple test methods:
- Buoyancy
For such a test, it is worth taking a piece of plastic and lowering it into water. If it starts to sink, then you won't need a primer. If, on the contrary, the material lies on the surface of the water, there is nowhere without a primer.
- Combustion
If the material begins to smoke during arson, the primer does not need to be applied, and if it burns “clearly”, the application of a primer layer is inevitable.
If you need to paint a non-new part, then it may need to be sanded, which will require sandpaper number 320-400 and water to remove cracks and cracks.
We paint plastic parts ourselves
When painting, the paint is applied to the surface with brushes, paint rollers on a woolen or mohair basis. Aerosols and sprays for small-scale production can also be used.
Even on premium cars, plastic elements are not particularly reliable, so repair and painting cases are much more common here than with metal elements. Who is already familiar with the procedure , he may not worry - the technology is almost the same, with the exception of some features related to chemical composition plastics. In general, the appearance of both interior components and plastic exterior elements is easily restored at home, without visiting specialized car services.
Choosing materials or how to paint plastic on your car and not regret
If it is decided to restore the appearance of plastic products, it is important to first find out the type of material. There are two types of plastics used in the automotive industry. We will not consider their chemical components here, we are only interested in the features of pre-treatment and subsequent application of paintwork.
Any do-it-yourself car plastic painting in the video looks like a simple operation. In practice, the type of plastic is first determined by the following two criteria:
- Combustion- take a small piece from the repaired component and set it on fire, while it should not have paint residues or dirt on it. If the flame is accompanied by black smoke and soot, then there is no need for preliminary priming (only processing with fine abrasive sandpaper). If the plastic burns with a pure flame, then a primer for the plastic is necessary.
- Buoyancy- the complete immersion of the plastic part indicates that there is no need for priming, if the part remains on the surface of the water, then it is impossible to do without applying the primer.
Basic materials
Before you paint plastic on a car, you need to take care of purchasing Supplies, which include:
- Acetone or white spirit.
- Primer for plastic (if necessary).
- Moisture-resistant sandpaper (P300 - P800).
- Paint for plastic products.
- Transparent acrylic lacquer.
Practice has already shown that when restoring the paintwork in certain areas of the body, it is rational to do with spray paint. This approach is also rational in our case, because the cultivated areas are small, and the purchase of an airbrush and a compressor is expensive. In addition, it is impossible to exclude options when you can not do without a regular paint brush.
How to dismantle plastic parts?
One of the important preliminary procedures is the careful dismantling of the necessary components from the passenger compartment and the outer plane of the body. The difficulty lies in the fact that their mounting options for each model are individual, and in some cases a special tool may be required. For example, to remove the dashboard on some cars, you cannot do without a pin of a special configuration.
Availability of a set universal tools greatly simplifies the painting process. It is important to prevent damage to the latches and loss of small parts. For this, steel forks are used, as well as polyurethane spatulas and keys for dismantling car radios and climate systems. In order not to forget the location of all the elements in the future, it is recommended to take intermediate photos of the disassembly process.
Do-it-yourself car plastic painting technology at home and video workflows
The consistency and thorough implementation of the technology for painting plastic elements guarantees the quality and durability of the paintwork. If you wish, you can familiarize yourself with the methodology using the available video materials provided by the masters. Briefly, the list of works consists of the following items:
- Degreasing the surface with a solvent or white spirit.
- Treat the plastic part with an antistatic agent (for example, Plak or Liqui Moly) so that dust does not attract to the plane when painted.
- Before you paint old plastic on a car, you need to eliminate defects with a special putty, which is more elastic than standard polyester.
- After drying, remove all irregularities with sandpaper P300 - P400, while the process must be carried out using water.
- Dry the part thoroughly and degrease its surface again.
- Prime the surface in 2-3 layers, avoiding streaks.
- The dried primer should be cleaned for painting with an abrasive sandpaper. P400 - P500.
- 2-3 layers of acrylic paint with plasticizing additives are applied to the cleaned surface, each layer needs to be dried for 15-25 minutes.
- After the final drying, a layer of varnish is applied.
- Polish the finished surface of the paintwork with polishing pastes.
Methodology has long been worked out, for its implementation it is desirable to have a grinder and appropriate accessories. But if necessary small areas can be processed manually.
The use of a brush when painting plastic parts of a car
It happens that painting with a brush looks more convenient and more profitable than with a can of spray paint. You will not see such a way of painting the regular plastic of a car with your own hands in the video. However, this does not mean that you should not pay attention to it, on the contrary, it guarantees high-quality adhesion and good coverage small fragments. However, when working, a number of features should be taken into account:
- Paint applied with a brush dries longer, so the drying time should be increased by 15-20 minutes.
- When painting, try to ensure the minimum thickness of the layer. To do this, in the process, the brush should be pressed well against the surface and work quickly.
- Carefully remove excess paint from the edge of the can.
- When working, you should maintain the same staining angle.
On a note
Do not forget that nitro enamel from cans contains an aggressive solvent in its composition. If you apply a thick layer of such paint, then the plastic may dissolve, not the whole part, of course, but the surface is very likely.
To prevent such a result, it is better to use a special primer. In addition, it is impossible to allow the application of a subsequent layer of paint without the previous one completely drying.
What do you need to paint plastic at home?
How to paint plastic at home?
Step by step instructions for painting plastic
Step_1 Clean the plastic surface from dirt with a sponge (brush) and soapy water. If dust and dirt remain on the product, the paint will lie unevenly and the product will have to be repainted. Heavy soiling, mold and erosion can be washed off with bleach. Dry the plastic product well before starting work.
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Step_2 To degrease the surface, wipe it with a solvent or white spirit, then wash off the applied composition and dry the product thoroughly. Step_3 To create a porous structure, sand the surface with fine sandpaper or special grinder. Grinding will allow the paint to lie perfectly evenly, due to the bonding of the paint and the porosity of the surface. After sanding, the surface will become matte. Properly selected sandpaper will not give the product unwanted roughness, therefore sandpaper it is better to choose with a grit of no more than 180. Be sure to remove the dust from grinding. |
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Step_4 Before painting the plastic at home, glue the places that are not subject to painting with construction tape and remove it immediately after the work is completed.
Step_5 Now you can start painting the plastic with spray paint. Shake the spray in the can for at least 30 seconds, spray the spray paint from a distance of 20-30 cm from the surface. You need to put the paint in smooth uniform movements. After the first layer has dried, which will take 15-20 minutes, apply subsequent layers of paint. When painting plastic, it is recommended to apply at least 2 - 3 layers of paint.
Step_6 After the spray paint dries, apply varnish in the same way and wait for it to dry. Complete (final) drying takes at least 2 - 2.5 hours. The product is ready to use!
What to pay attention to when painting plastic?
As we have already said, there are different types of plastic, so it is recommended to carefully consider the choice of paint. Ideally, you need to use a special paint for plastic.
5 In addition, please note that for aerosol paints in cans there are special tips for convenient regulation of the amount of sprayed paint and its uniform distribution.
We talked about the most simple and efficient way painting plastic at home using spray paints, however, this procedure can also be carried out with a regular brush with a brush using canned paint.
How to paint plastic at home with a brush?
Painting plastic items using a brush is somewhat different from the method described above and has its advantages and disadvantages. One of the features is long term drying, which means that the product must be completely isolated from dust on the freshly painted surface, which is not so easy at home. That is why the brush painting method is used for painting objects that do not require special attention. The technology for painting plastic with a brush at home is quite simple and essentially repeats the process of working with spray paint:
Step_5 This is an additional step. If you want to further protect the painted surface, you can apply acrylic varnish. Apply varnish ONLY to completely dry paint. In the case of aerosols, we know that the paint takes 15-20 minutes to dry, but here everything will depend on what kind of paint you use. Lacquer drying time 2 - 2.5 hours
What should I pay attention to when applying paint on plastic with a brush?
1 Apply the paint in a thin layer, constantly pressing the brush against the surface
2 When taking the paint on the brush, do not dip the brush into the paint completely
3 Take into account the coloring angle - it should be the same.
4 For even coverage, apply the paint in wide swathes to fill the pores, and then carefully blend the applied layer.
So, we talked in detail about how and how to paint plastic at home. Feel free to start painting and make sure from experience that it is not at all difficult, and the result is worth the time and effort spent!
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Most home crafters think that painting plastic parts with their own hands is a fairly simple task. However, not all types this material are equally suitable for this. Of course, it is possible to paint these surfaces, and the material will fall on them quite evenly, but the life of the coating will be short.
After drying, the paint will begin to peel, crack and flake off.
Below we will try to give advice on:
- what plastic is to be dyed at home;
- how to do it right;
- how to paint plastic.
What you need to know about plastic
This product happens different types, and each of them has its own unique properties. Therefore, the process of staining for each is different, sometimes radically different. By the way, in the work you may encounter such plastics that cannot be painted.
An example would be products made of polyethylene (PE) or polypropylene or polyethylene, from the surfaces of which the paint will peel off in layers. Therefore, it is almost impossible to paint metal-plastic pipes made from polyethylene. So it is better to immediately select the desired shade.
Automotive plastics can be divided into two types:
- require;
- do not require.
Tip: before you completely wipe the paint off the plastic, test with the solvent on a small area of the surface.
Before staining, it is necessary to determine the type of material as follows:
- Dip a small piece of the product or its entirety into water:
- if it goes under water, then the part does not need to be primed;
- if it will remain on the surface, therefore, the material requires the application of a special primer mixture for plastic.
- The next option is to set fire to a piece of plastic part cleaned of dirt and paint:
- will burn with black smoke and soot, which means that you can do without applying a primer;
- the flame is even and clean, therefore, its surface must be primed.
How to paint plastic
Suggested below detailed instructions which will help you understand this process. Try not to deviate from it to get the desired final coverage.
Coloring plastic consists of several stages:
- Degreasing surfaces with special compounds.
- Soil application.
- Applying an acrylic primer.
- Sanding acrylic primer.
- Surface coloring.
Features of coloring plastic products
- PVC or ABS plastics can be painted, but they must first be treated with primers to increase adhesion (adhesion). You can buy them in car dealerships, where they are sold under the name “plastic primer”, or in stores selling paints and varnishes, for example, Otex primers from the Tikkurila company. These compounds can be applied by wiping or spraying on the surface, after which you need to wait until they dry, usually 1-2 minutes.
- Make sure that the surface of the prepared under is free of dirt and oil, and also that they are dry..
Tip: you can not conduct additional preparation of surfaces for painting if you work with ABS plastics or polystyrene, which will be coated with acrylic paint on water based.
- It is desirable that the temperature of plastic products, paint and painting equipment be the same. Ideal conditions can be considered such when the room temperature is from 18˚С, and the humidity does not exceed 80%.
- Paint in one layer, the thickness of which should be about 60 microns.. With a smaller parameter top coat may seem fragile and the paint will not be able to stay on the surface of the product for a long time. At the same time, with a thick layer (more than 120 microns), the drying time will increase, which often has a bad effect on appearance coatings.
- Dry the plastic after painting at a temperature of 18-60˚С, it depends mainly on the thickness of the applied layer. For example, with a thickness of 90-120 microns, drying at a temperature of 50 ° C and a humidity of 65% can last about 3 hours. Polypropylenes and polyamides can be dried at 100°C and in 20 minutes.
- The paint completely dries (polymerizes) on plastic surfaces in 5-7 days, but when temperature regime low, high humidity and a thick layer of paint, this time period can increase several times.
spray paint
This is one of the most comfortable. The capacity of the spray can is 400 mm, which is enough for painting windows, slopes and small parts. Due to the wide variety of ready-made shades, this method is most often used in home repairs, although their price is more expensive than similar compositions in banks.
Tip: no need to think about how to remove paint from water-based plastic - treat it with plain water, but you need to hurry, otherwise the process will become much more complicated after drying.
Most often, an acrylic universal composition is used, which dries quickly, thanks to which it is possible to transform the interior of the room in a short time. Lifetime spray paint exceeds three years.
An important role is played by its convenience when applied to the selected surface. You do not need any additional tools for this, and you do not need to have special professional skills. Layer under pressure to lie down on the plastic evenly.
Tip: before you start work, you need to make sure that the room is well ventilated, it is best to open windows for this. In addition, it is necessary to adhere to elementary safety precautions - protect your eyes with special glasses, and the respiratory organs with a paint respirator.
Conclusion
Applying paint to plastic products has its own feature associated with the property of the surface. Before starting work, it is necessary to determine its characteristics and select the appropriate materials for the implementation of the process. The video in this article will help you find additional information on this topic.
