Plastic sills are one of the most vulnerable places in a car’s exterior. They are constantly exposed to mechanical stress: from accidental kicks when landing to friction with shoes, bicycles or baby strollers. Even careful drivers sooner or later encounter a network of small scratches that spoil the appearance of the car and reduce its market value. In this article we will look at 7 proven methods of protection, which will help keep the thresholds in perfect condition for years to come.

The peculiarity of plastic thresholds is that they are not only susceptible to physical damage, but also fade faster in the sun, lose color and become rough. This makes the problem worse: a porous surface more easily attracts dirt and abrasive particles, which act like sandpaper with each touch. Solutions range from budget (do-it-yourself vinyl) to premium (professional ceramic coating), and we'll go into detail about each of them - with pros, cons and step-by-step instructions.

Why does the plastic on the thresholds scratch faster than other parts?

Car thresholds are made of thermoplastic polymers - usually ABS plastic (acrylonitrile butadiene styrene) or PP (polypropylene). These materials were not chosen by chance: they are lightweight, corrosion-resistant and relatively cheap to produce. However, they have critical disadvantages:

  • 🔹 Low Shore hardness: plastic is softer than metal and body paint, so it gets scratched even from minor loads.
  • 🔹 Porous structure: microscopic pores become clogged with sand and dust, which act as an abrasive during friction.
  • 🔹 Sensitivity to UV rays: Under the sun, plastic becomes brittle and prone to cracking.
  • 🔹 Lack of protective layer: Unlike the body, the sills are rarely coated with varnish or ceramics at the factory.

Interesting fact: according to car service statistics, 80% of scratches on door sills appear in the first 2 years of car operationwhen the owner does not yet have time to take protective measures. Moreover, 60% of damages are caused not in parking lots, but in everyday situations - for example, when a passenger touches the threshold with a bag or a child leans his foot while boarding.

Another reason for accelerated wear is improper care. Many drivers wash their sills with hard brushes or aggressive chemicals (for example, wheel cleaners), which destroys the top layer of plastic. We will return to this in the prevention section.

📊 How often do you notice new scratches on the door sills of your car?
Every week
Once a month
Once every six months
Never paid attention

Method 1: Vinyl film - budget and universal protection

Pasting with vinyl film is the most popular method of protecting thresholds among car owners. Modern vinyls (eg. 3M Scotchprint or Orafol) not only prevent scratches, but also give the thresholds an original look. The film can be matte, glossy, “carbon-look” or even with a metal texture.

Advantages of vinyl:

  • 💰 Low cost: from 500 to 2000 rubles for a set of thresholds (depending on the brand of film).
  • 🛡️ Protection against 90% mechanical damage: a film with a thickness of 100–200 microns can withstand shock and friction.
  • 🎨 Aesthetics: You can match the color to the body or create a contrasting accent.
  • ⏱️ Service life: 3–5 years with proper care.

How to glue vinyl yourself:

Prepare the surface: wash the sills with car shampoo and degrease isopropyl alcohol|Heat the film with a construction hairdryer (temperature 60–80°C) for better elasticity|Glue the film starting from the center of the threshold, smoothing it with a rubber spatula from the middle to the edges|Cut off the excess with a stationery knife, leaving an allowance of 1–2 mm for folding|Warm the edges with a hairdryer and press them to the threshold for reliable fixation-->

Important: if you have never glued vinyl, practice on an unnecessary piece of plastic. It is almost impossible to correct errors during pasting (bubbles, wrinkles) - you will have to re-glue it again.

⚠️ Attention: Do not use cheap Chinese films without UV protection. They turn yellow after 6–12 months and begin to flake off. The best choice is vinyl with UV filter and caste glue (for example, 3M 1080 or Avery Dennison SW900).

Method 2: Liquid rubber - elastic and durable coating

Liquid rubber (for example, Plasti Dip or Rubber Paint) is a polymer coating that is applied by spraying or brushing. After drying, it forms a durable elastic layer that is resistant to scratches and chemical influences. The main advantage over vinyl is possibility of local repair: If a small area is damaged, you can simply touch it up.

Advantages of liquid rubber:

  • 🔧 Easy to apply: does not require professional skills.
  • 🔄 Removability: The coating can be removed without a trace if you get tired of it.
  • 🌡️ Resistance to temperature changes: does not crack in the cold and does not melt in the heat.
  • 🎨 Design variability: You can combine colors or apply stencil designs.

Cons:

  • ⏳ Long drying: Full polymerization takes 24–48 hours.
  • 💦 Sensitivity to moisture: Can only be applied in dry weather (humidity < 60%).

Application instructions:

  1. Clean the thresholds degreaser (for example, APP W900).
  2. Apply 3-4 layers of liquid rubber at intervals of 15-20 minutes (each layer should be thin!).
  3. For a glossy effect, add a layer on top Plasti Dip Glossifier.
  4. Do not wash your car for 2-3 days after application.
💡

If you want to save money, buy liquid rubber in aerosol cans (for example, Motip Dupli-Color). For the thresholds of an average car, 2–3 400 ml cylinders are enough.

Method 3: Ceramic coating - premium protection for 5+ years

Ceramics (nano-ceramics) is liquid glass based on silicon dioxide (SiO₂), which after polymerization forms a hard coating with dirt-repellent properties. Ceramic is second only to diamond in hardness, so it reliably protects plastic from scratches, chemical stains and fading.

Comparison of ceramics with other methods:

Parameter Vinyl film Liquid rubber Ceramics
Cost (for thresholds) 500–2000 ₽ 1500–3000 ₽ 5000–12000 ₽
Service life 3–5 years 2–4 years 5–7 years
Scratch resistance High Average Maximum
Difficulty of application Average Low High (requires polishing)
Possibility of repair No (only plywood) Yes (local touch-up) Yes (polishing or recoating)

Ceramics are applied in 2 stages: first preparatory polishing (removing micro-scratches), then the coating itself. The process takes 4–6 hours and requires professional equipment, so it is better to entrust it to certified professionals. For example, in Moscow and St. Petersburg the service costs from 5,000 rubles per threshold, in the regions - from 3,500 rubles.

⚠️ Attention: Cheap ceramics (up to 2000 ₽ per treatment) are often diluted with solvents and last no more than a year. Check with the master the certificate for the composition used (for example, Ceramic Pro, Gyeon or NanoSkin).
💡

Ceramic coating is the only method that not only protects against scratches, but also simplifies maintenance: dirt from the thresholds is washed off with plain water without detergents.

Method 4: Shrink film - an invisible shield for plastic

Shrink film (eg XPEL Ultimate Plus or LLumar) is a transparent polyurethane coating that is applied to thresholds and “shrinks” under the influence of temperature. It completely replicates the texture of plastic, remaining invisible, but at the same time withstands impacts and friction.

Where it is used:

  • 🚗 New cars: to maintain the factory appearance of the sills.
  • 🔄 Car with restored sills: protection after painting.
  • 💎 Premium cars: where aesthetics are important (e.g. Mercedes S-Class or Porsche Panamera).

How to apply:

  1. The thresholds are washed and degreased.
  2. The film is cut out according to patterns (for popular car models, patterns are already in the database).
  3. Stick with slip solution (slip solution).
  4. Dry with an infrared lamp or in a special chamber.

The cost of covering with thermal film starts from 3,000 rubles for thresholds. The main disadvantage is the difficulty of applying it yourself: without experience, it’s easy to leave bubbles or wrinkles.

Method 5: Door sills - mechanical protection

Overlays (or strength) are plastic or aluminum elements that are mounted on top of the factory thresholds. They take on all impacts and scratches, keeping the original part intact. Overlays are:

  • 🔹 Universal: Suitable for most models (eg from Heko or Thule).
  • 🔹 Original: developed by the car manufacturer (for example, Toyota or Volkswagen).
  • 🔹 Tuning: Backlit or aggressive design (brands Mansory, ABT).

Pros of overlays:

  • 🛡️ 100% protection from mechanical damage.
  • 🔧 Easy installation: attached with clips or double-sided tape.
  • 🔄 Replacement without consequences: Can be removed at any time.

Cons:

  • 💰 Cost: original linings cost from 8,000 rubles, tuning ones - up to 30,000 rubles.
  • 📏 Increase in size: the thresholds become wider by 2–5 cm, which can interfere with parking.

Example: overlays Heko Winddeflector for Skoda Octavia cost ~4000 rubles per set and are installed in 20 minutes without drilling.

How to choose pads by size?

If you are purchasing universal trims, measure the length and width of your thresholds. The optimal length of the lining should be 1–2 cm shorter than the threshold (so as not to stick out), and the width should be 0.5–1 cm wider (for reliable overlap). For accuracy, use masking tape: stick it along the edge of the threshold and outline the outline with chalk.

Method 6: Polishing and waxing - temporary protection

If you are not ready to spend money on long-term solutions, you can use polishing with protective wax. This method will not save you from deep scratches, but will reduce the risk of minor damage and give the thresholds a shine.

What you will need:

  • 🧴 Abrasive paste (for example, 3M Rubbing Compound).
  • 🧼 Non-abrasive polish (for example, Meguiar’s Ultimate Polish).
  • 🕯️ Wax or sealant (for example, Collinite 845 or Turtle Wax Ice Seal N Shine).
  • 🔧 Polishing machine (or a soft sponge for hand polishing).

Step by step instructions:

  1. Wash the thresholds with car shampoo and dry.
  2. Apply abrasive paste to the foam nozzle and polish the thresholds at medium speed (1500–2000 rpm).
  3. Remove any remaining paste with microfiber.
  4. Apply a non-abrasive polish to restore shine.
  5. Cover the thresholds with wax or sealant (lasts 2-4 months).

This method requires repetition every 3–6 months, but it costs 300–500 rubles per procedure.

Method 7: Anti-gravel coating - for extreme conditions

Anti-gravel compounds (for example, Body 950 or Raptor U-Pol) were originally developed to protect the underbody and wheel arches, but are also suitable for sills. They create a thick (up to 1 mm) elastic layer that is resistant to impacts from stones and sand.

When relevant:

  • 🏔️ Off-road travel (for example, on UAZ Patriot or Toyota LC Prado).
  • 🚧 Operation in construction or quarry conditions.
  • ❄️ Winter riding (protection from reagents and ice).

How to apply:

  1. Sand the sills with sandpaper P800–P1000 for better adhesion.
  2. Degrease the surface antisilicon.
  3. Apply 2-3 layers of anti-gravel at intervals of 15 minutes (use a spray gun or spray can).
  4. Dry for 24 hours at +20°C.

The downside of anti-gravel is its rough texture, which can be dissonant with the overall appearance of the car. But this is the most durable coating of all listed.

Prevention of scratches: 5 rules for caring for thresholds

Even with protection, thresholds require careful handling. Follow these rules to extend the life of your coating:

  • 🧹 Wash the thresholds with a separate sponge: Do not use the same as for wheels (it leaves dirt and sand particles on it).
  • 🧴 Avoid harsh chemicals: Do not use disc or brake cleaner on the sills.
  • 👟 Watch your passengers' shoes: Metal heels on shoes or heels leave deep scratches.
  • 🅿️ Park carefully: Press against the curb so that the sills do not rub against it.
  • 🌞 Use UV protection: once every 2-3 months, apply a spray with UV filter (for example, Sonax Plastic Care).

An interesting life hack: if there are already small scratches on the thresholds, you can disguise them pencil for plastic (for example, Renault Touch-Up Stick). It fills microcracks and restores color.

💡

Regular care of thresholds increases the service life of the protection by 2-3 times. For example, vinyl film will last 2 years without maintenance, and up to 5 years with proper washing and waxing.

Frequently Asked Questions

Is it possible to paint the thresholds instead of protection?

Paint (even with varnish) does not protect against scratches - it only masks them. Moreover, chips on painted plastic are more noticeable than on the original. If you decide to paint, be sure to coat the sills on top transparent film or ceramics.

Which method of protection is the most durable?

Leading in service life ceramic coating (5–7 years), followed by shrink film (4–6 years old). Vinyl and liquid rubber last 2–4 years, anti-gravel - up to 5 years (but requires updating).

Is it possible to combine protection methods?

Yes! For example, many owners of premium cars first paste over the door sills thermal film, and applied on top ceramics for added strength. Another option: pads + liquid rubber at the joints.

How to care for thresholds in winter?

In winter, plastic becomes brittle, so:

  1. Wash the thresholds only warm water (don't ice!).
  2. Treat after washing silicone grease (for example, WD-40 Specialist) to prevent ice from freezing.
  3. Avoid metal scrapers to remove snow - use plastic or silicone.
How much does threshold protection cost at a car service?

The cost depends on the method and region:

  • Vinyl film: 1500–3000 ₽.
  • Liquid rubber: 2000–4000 ₽.
  • Ceramics: 5000–12000 ₽.
  • Thermal film: 3000–6000 ₽.
  • Overlays: 4000–20000 ₽ (including parts).

Self-protection will cost 2–3 times less.