Aggressive road environment, flying from under the wheels of gravel, sand and reagents can turn the appearance of a new car into a depressing sight in just one season. The most vulnerable areas of the body are traditionally considered to be the thresholds, which take the main blow of abrasive influence when driving on the highway or city highways. Ignoring the protection of these zones inevitably leads to the appearance of deep chips, scratches and, ultimately, to a focus of corrosion, the elimination of which will require expensive body repairs.
The most effective and modern solution to the problem is to paste the thresholds. armored (PPF - Paint Protection Film) This material is a high-strength polyurethane coating that not only hides minor defects, but also takes on mechanical damage, keeping the native paint coating (LCP) in perfect condition. Unlike liquid protection or waxes, the film has a thickness sufficient to absorb the energy of the stone impact and the ability to self-heal when heated.
The process of applying protection requires accuracy, cleanliness and compliance with technology, but it can be performed independently in garage conditions. Well-chosen polyurethane And careful surface preparation are key success factors. In this article, we will discuss in detail how to choose the material, what tools you will need and how to properly paste the protection so that it serves for years without peeling off and turning yellow.
Material choice: polyurethane or vinyl?
The first and most important step is to choose the right material. There are many films on the market, but not all are suitable for protecting thresholds from stone strikes. The main division is between vinyl and polyurethane materials. Vinyl films (PVC) were originally designed to change color or mat the body. Their thickness is usually 100-140 microns, which is not enough to provide serious protection against gravel at high speeds. They can protect against sand and small scratches, but when struck with a stone, vinyl is likely to break through, transferring the energy of the impact to the metal.
For thresholds is necessary. polyurethane (TPU). It is a shape memory material that has high elasticity and tensile strength. The thickness of the protective layer of such films often exceeds 180-200 microns. When impacted, polyurethane cushions, and due to the property of "self-healing", small scratches on the surface of the film disappear under the influence of heat from the sun or hot water. The cost of polyurethane is higher, but the savings on future repair of thresholds pay off the investment many times over.
When choosing, you should also pay attention to the presence of an upper protective layer, often called the top coat. It is this layer that is responsible for hydrophobic properties (the lotus effect) and resistance to chemical reagents. Cheap analogues without quality top coat quickly lose gloss, turbidity and turn yellow under the influence of ultraviolet light.
⚠️ Note: Do not use cheap vinyl films for thresholds, intended only for decorative purposes. When crushed, they will not work like armor, but only create the appearance of protection under which the LCP will be destroyed.
A high-quality polyurethane must have a quality certificate from the manufacturer, which indicates the parameters of adhesion, stretching and resistance to UV radiation. Buying material "on weight" without marking from unverified suppliers is a lottery, the result of which can disappoint the owner of the car after six months of operation.
Tools and workplace preparation required
The quality of the pasting is 80% dependent on the preparation and the tools used. Work with armored film "on the knee" or in a dusty room is categorically impossible - any grain of sand caught under the layer will be a noticeable defect. To work, you will need a clean, well-lit room, preferably with an air temperature not lower than +18 ° C, since the cold material becomes hard and does not stretch well.
The basic set of tools includes not only the film itself, but also specialized devices for working with it. Raquel is the main tool of the installer. It should be hard, but with soft edges so as not to scratch the material. Also indispensable is the squeezing for hard-to-reach places and a hair dryer, which will allow you to activate the glue and stretch the film over the complex forms of thresholds.
- 🛠️ Squeakers set: hard plastic rackel for water purification and soft felt rackel (or covered with microfiber) for finish polishing.
- 🌡️ Building hair dryer: It is necessary for heating the material during the formation of edges and activation of the adhesive layer.
- 💧 Pulverizer: for application of the mounting solution (soap solution or special fluid).
- 🧼 Degreasing: isopropyl alcohol or a special silicone cleaner.
- ✂️ Knife with blades: It is new and sharp, for the exact cut of the material.
Special attention should be paid to the liquid for installation. Professionals use special services lotionswhich allow the film to move on the surface until drying. At home, a solution of distilled water and a couple of drops of baby shampoo or dishwashing products are often prepared, but it is important not to overdo it with concentration, otherwise the glue may not catch.
⚠️ Note: It is strictly forbidden to use aggressive solvents (acetone, gasoline) for degreasing immediately before the sticker, unless you are sure of the resistance of the LCP. They can damage the varnish by making it matte.
Preparation of the surface of thresholds for pasting
Surface preparation is the foundation of all work. If dirt, bitumen or polyrene remains on the thresholds, the film simply will not stick or will depart after a few days along with dirt particles. The first stage is a thorough car wash, after which the zones of the thresholds are cleaned of contaminants.
To remove bitumen spots and traces of insects, use special bitumen cleaners. After chemical treatment, the surface must be thoroughly washed with water and dried. The next step is deep cleaning with a clay napkin or clay bar. This procedure allows you to pull metal particles and ingrained dirt from the pores of the varnish, making the surface smooth like glass.
The final stage of preparation is degreasing. A rag of microfiber, abundantly moistened in a degreaser, carefully wipe the entire area of future work. Do not forget about hard-to-reach places where plastic docks with metal - there often accumulates silicone from previous polishing.
☑️ Checklist of preparations
After degreasing, it is no longer possible to touch the surface with your hands, since skin fat will violate the adhesion of the glue. If you accidentally touched the prepared area, the degreasing procedure must be repeated. A perfectly clean surface is the key to the absence of bubbles and detachments in the future.
Application technology: wet and dry methods
There are two main ways of pasting: wet and dry. For beginners and for working with polyurethane film in large areas such as rapids, it is highly recommended. wet-method. It allows you to adjust the position of the film, remove dust from under the material and avoid premature grasping of the glue.
With the wet method, an mounting solution is abundantly applied to the defatted surface and on the adhesive layer of the film. The film is laid on the threshold and moves freely on the surface until you align it exactly at the edges. After positioning, the process of liquid discharge begins. The movement of the rakel should go from center to edges, gradually squeezing the water out.
The dry method is only suitable for experienced craftsmen and small elements. The film is glued immediately to a dry surface, which requires jewelry accuracy the first time, since it will not be possible to unstick and reglue the material without losing the adhesive properties. For rapids, this method is risky due to their complex geometry and length.
| Comparison parameter | Wet method | Dry method |
|---|---|---|
| Speed of operation | Slower (takes time to dry) | Hurry up (right away) |
| Possibility of correction | Tall. | Absent. |
| Risk of clutter | Minimum | High-pitched |
| Skills requirement | Low/Mediocre | High. |
During this period, it is not recommended to wet the car or use high-pressure washers.
Step-by-step instructions for putting up thresholds
The process of pasting begins with cutting the material. You can buy ready-made kits for a specific model of the car (see below).pre-cut kits), which perfectly repeat the contours, or cut the film yourself with a margin of 1-2 cm at the edges. Self-cutting requires caution not to damage the LCP with a knife.
We apply abundantly the mounting solution on the threshold and on the glue side of the film. Carefully place the film on the surface, combining the edges. Start the water distillation from the center to the edges with a hard racket. The movements must be confident, but not excessively strong, so as not to damage the structure of the material.
We pay special attention to the edges and curves. Polyurethane requires heating to stretch. Carefully warming the material with a hairdryer (temperature about 60-70 ° C), stretch it and wrap it over the edge of the threshold. This will prevent film bullies in the future. After the formation of the edges, we once again pass over the entire surface, strengthening the pressing.
⚠️ Warning: Do not overheat the polyurethane! At temperatures above 90-100°C, the material can be permanently deformed or change color. Keep the hair dryer in constant motion.
After the main water is ejected, let the film "grab" a little (5-10 minutes), then walk along the entire surface with a soft felt rakel with effort. This will remove the microbubbles and provide final adhesion. The excess film at the edges is carefully cut with a sharp knife if you have not made a twist.
Drying, polishing and coating care
The final stage is drying and quality control. Although the film may appear dry visually, moisture remains underneath. To speed up the process, you can use a hair dryer, gently walking along the entire surface, but without fanaticism. Residual moisture will escape through the micropores of the material during the day.
If there are small bubbles of air or water left after drying, do not panic. Most of them will disappear on their own within 24 to 48 hours in the sun. Large bubbles can be gently punctured with a thin needle (only in extreme cases!) and rolled.
What to do if the film is darkened?
Sometimes after pasting the film may look cloudy or have an “orange peel”. This is normal for some types of polyurethane immediately after installation. The clouding is caused by the microporousness of the material and moisture residues. As a rule, after 1-2 weeks of operation in the sun, the film gains gloss and becomes completely transparent. If the turbidity does not pass a month, it is possible that the material is of poor quality or the technology is broken.
Caring for armored film is simple: wash the car as usual, avoiding aggressive chemicals in the first 2-3 days. Periodically (every 3-4 months) it is recommended to apply special sealants or sprays for PPF, which restore the hydrophobic layer and facilitate cleaning of dirt.
To extend the life of the film, avoid washing the body with high pressure devices (Karcher) from a distance of closer than 30 cm to the edges of the pasting, so as not to pick up the material.
Regular inspection of the state of the thresholds will allow you to notice the damage to the film itself in time. If the impact was too strong and the film broke, it can be replaced locally, retaining the rest of the protection.
Frequently Asked Questions (FAQ)
How long does the film dry after pasting?
Primary grasping takes 1-2 hours, but complete glue polymerization and moisture evaporation take 24 to 48 hours. At this time, it is advisable not to wet the car and not to put it in heavy rain. The final transparency and gloss appear after 1-2 weeks.
Can I use the film in winter or in a cold garage?
Glued at a temperature below +15 ° C is not recommended. Polyurethane becomes stiff, stretches poorly and can break on the folds. In addition, the adhesive layer is not activated properly. If the work is unavoidable, the room should be heated.
Will the film protect against heavy stones?
The 200 micron thick armor film protects against chipping, sand, small stones and branches. However, from a direct impact of a large sharp stone at high speed or from a serious accident, it will not save - in such cases, it works as an additional layer, taking some of the energy, but can be pierced.
Do I need to remove the thresholds for pasting?
In 95% of cases, the thresholds are not removed. Professional installers glue protection with a neat turn of the edges or a joint, using special patterns. Removing the elements increases the risk of damage to the fasteners and takes longer.
How to remove the old film if it turns yellow?
High-quality polyurethane lasts 5-7 years and does not turn yellow. If the film needs to be removed, the edge is gently slapped, and the material is removed at an angle of 45 degrees, preferably with a heated hairdryer. The glue from a quality film leaves no trace on the LCP.