Crack in the plastic radiator grille Toyota Corolla 2018 or bent slats on a metal grill BMW X5 E70 - not always a reason to completely replace a part. In 80% of cases, damage is eliminated by soldering, cold welding or epoxy glue, if the material and technology are chosen correctly. For example, longitudinal cracks up to 15 cm long on plastic are successfully repaired with reinforced fiberglass, and deformations of metal gratings are corrected without traces using a gas torch and a wooden hammer. The main thing is not to use hot glue for plastic (it melts at +80°C) and not to cook aluminum gratings with a regular inverter without argon.

Before starting repairs, inspect the grille for hidden damage: cracks often extend deep into mounting holes or under decorative trims. Do a flex test - if the plastic crumbles when bent, a complete replacement will be required. For metal grilles, corrosive wear is critical: if rust has eaten through the lamellas, the welding seam will last no more than a season. This article provides step-by-step instructions for all types of grilles, including repair of chrome elements and restoration of the factory plastic texture.

1. Diagnosis of damage: when repair is possible and when not

The first step is to determine grating material and the nature of the defect. Plastic grilles are divided into three types:

  • 🔹 ABS plastic (matte, slightly flexible) - repairable by soldering or epoxy glue with reinforcement.
  • 🔹 Polypropylene (PP) (smooth, slippery) - requires special PP glue or hot air welding.
  • 🔹 Polyurethane (rubber-like) - can only be restored with liquid rubber or two-component glue.

Metal gratings can be aluminum (easily bent, not magnetic) or steel (heavier, magnetic). Critical damage, in which repair is pointless:

  • 🚫 Cracks in places where it is attached to the bumper (the load during movement will tear the seam).
  • 🚫 Through corrosion on steel gratings (the welding seam will quickly rust).
  • 🚫 Chipped fragments with an area of more than 30% (restoration of shape is impossible without loss of strength).
⚠️ Attention: If the grille is attached to the radiator frame, check the integrity of the connecting latches. Their failure leads to vibrations and repeated cracks after repair.
Type of damage Plastic Aluminum Steel
Cracks up to 10 cm Soldering + reinforcement Argon welding Cold welding
Lamella deformation Impossible Leveling with a torch Straightening with a hammer
Broken elements Epoxy glue + putty Welding with filler rod Semi-automatic welding
Scratches/abrasions Polishing + painting Polishing with GOI paste Anticorrosive + painting

2. Repairing plastic grilles: soldering vs glue

For plastic soldering You will need a soldering iron with a power of 60–100 W with a flat tip, solder for plastic (ABS or PP rod) and metal mesh for reinforcement. Technology:

  1. Sand the crack with sandpaper P120 and degrease with acetone.
  2. Heat the edges of the crack with a soldering iron until the plastic melts (do not overheat - ABS begins to bubble at +250°C).
  3. Inject solder into the crack while pressing the edges. For reinforcement, drown a piece of metal mesh into the molten mass.
  4. After cooling, sand the seam P400→P800 and paint it.

Glue method Suitable for infusible plastics (eg polypropylene). Use two-component formulations:

  • 🧪 3M Scotch-Weld DP8005 — for ABS and polyurethane, can withstand +120°C.
  • 🧪 Loctite Plastics Bonding System — with primer for PP, setting time 5 minutes.
  • 🧪 Epoxy + fiberglass — for large cracks (apply in layers with a layer of fabric).

Degrease the surface with acetone or white spirit | Remove the paint coating in the repair area using P180 sandpaper | Heat the crack with a hairdryer (to remove moisture) | Apply a primer (for adhesive methods)

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⚠️ Attention: Do not use superglue (cyanoacrylate) - it creates a brittle seam that will crumble from vibrations. For chrome-plated plastic grilles, sand the plating off first, otherwise the adhesive will not bond to the base.

3. Restoration of metal grating: welding and straightening

Aluminum grates are cooked argon arc welding (TIG) with rod ER4043 (for silumin) or ER5356 (for pure aluminum). Mode:

  • 🔥 Current: 60–80 A (depending on the thickness of the metal).
  • 🔥 Polarity: Alternating Current (AC).
  • 🔥 Gas: argon 100%, flow rate 8–10 l/min.

After welding, the seam is cleaned with a stainless steel brush and passivated with phosphoric acid to protect against corrosion.

Steel gratings are repaired semi-automatically (CO2) or cold welding (for small cracks). Popular formulations:

  • 🛠️ ABRO Steel — withstands up to +260°C, hardening time 1 hour.
  • 🛠️ Poxipol — for thin-walled gratings (seam thickness up to 5 mm).
  • 🛠️ Devcon Plastic Steel — with metal filler, suitable for straightening.

For straightening bent slats use:

  • 🔨 Wooden hammer (for aluminum).
  • 🔨 Metal hammer with a bronze striker (for steel).
  • 🔨 A set of straightening spoons (for hard-to-reach places).

Plastic Soldering Iron|Welding Machine|Cold Welding Kit|None of the above-->

4. Restoration of chrome plating

If the grille had electroplating (chrome, nickel), after repair it needs to be restored. To do this:

  1. Sand the repaired area until smooth (P1000→P1500).
  2. Apply acid soil (for example, Reoflex Acid Primer) for adhesion.
  3. Paint chrome imitator (aerosol Spray Max 2K Chrome or Alsa Chrom Effect).
  4. Protect with varnish 2K MS (two-component, UV resistant).

For local repairs chromium use:

  • 🎨 Liquid chrome (for example, Caswell Chrome Plating Kit) - applied with a brush, requires preliminary nickel plating.
  • 🎨 Chrome film (vinyl 3M DI-NOC) - sticks to a smooth surface, lasts 2-3 years.
How to distinguish real chrome plating from paint?

Real chrome has a mirror shine without yellowing, is not erased with acetone and is magnetic (if the substrate is steel). The imitation paint fades over time, is scratched by a coin and does not conduct electricity.

5. Painting the grille after repair

To paint a repaired grille, use automotive enamels in cans or spray gun. Step by step process:

  1. Degrease the surface antisilicon (for example, APP Anti-Silicone).
  2. Apply adhesive primer (for plastic - Plastic Primer, for metal - Wash Primer).
  3. Paint in 2-3 layers, drying for 10-15 minutes between layers. Suitable for plastic Motip Plastik Lack, for metal - R-M Onyx HD.
  4. Cover matte or glossy varnish (depending on the original coating).

Select the color according to the manufacturer's code (for example, Toyota 1G3 for silver metallic). If the code is unknown, use tinting card or color matching service by VIN.

Grille type Soil Paint Varnish
ABS plastic Plastic Primer Motip Plastik Lack 2K MS Clear
Polypropylene PP Adhesion Promoter Spray Max 2K U-Pol Clear
Aluminum Wash Primer R-M Onyx HD Sikkens Autoclear
Steel Epoxy Primer PPG Deltacron PPG Global Refinish
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To paint chrome parts, use a stencil of masking tape to avoid touching adjacent elements. Apply paint in thin layers from a distance of 20–25 cm to avoid smudges.

6. Installation of the grille after repair

Before installation, check:

  • 🔧 Aligning the mounting holes with the bumper (if necessary, expand them with a drill).
  • 🔧 Gaps between the grille and the body (must be uniform, 2–3 mm).
  • 🔧 The functionality of the hood locks (the grille should not block access).

For fastening use:

  • 🔩 Piston clips (for example, Hella 8XH 355 343-121 for plastic gratings).
  • 🔩 Bolts with rubber seals (for metal grilles, tightening torque 8–10 Nm).
  • 🔩 Double-sided tape 3M VHB (for temporary fixation during fitting).
⚠️ Attention: If the grille is attached to the radiator frame, make sure that there is at least a 10mm gap between it and the radiator for air circulation. Otherwise, the engine may overheat.

7. Prevention of re-injury

To make the repaired grill last longer:

  • 🛡️ Install safety net (for example, AVS Insect Screen) from stones and insects.
  • 🛡️Apply anti-gravel film (3M Scotchgard) to vulnerable areas.
  • 🛡️ Wash the grill regularly in a contactless way (Kärcher high-pressure cleaners with 25° nozzle).
  • 🛡️ Treat metal grilles in winter anticorrosive (for example, Tectyl ML).

Avoid:

  • ❌ Washings with alkaline shampoos (eat away paintwork).
  • ❌ Parking with your nose to the side of the road (sand and gravel hit the grille when overtaking).
  • ❌Uses abrasive polishes (for example, 3M Rubbing Compound) on chrome surfaces.
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Even a well-repaired grill will last no more than 2–3 years with active use. If the damage continues, consider installing a protective body kit or replacing the grille with an aluminum one (for example, from AliExpress for popular models).

Frequently asked questions

Is it possible to restore a lattice with large missing pieces?

If more than 30% of the area is missing, repair is impractical - the seams will not withstand the load. In this case, it is better to buy a used grille for disassembly (for example, at Avito or eBay) or order a replica from Chinese manufacturers (AliExpress, Taobao). For rare models (for example, Lexus LFA) you can make a fragment on a 3D printer from ABS plastic and glue it with epoxy.

What adhesive is best for repairing a Mercedes plastic grille?

For gratings Mercedes (usually made of polypropylene) optimal Loctite Plastics Bonding System or 3M DP8005. Be sure to prime the surface before gluing. 3M Plastic & Paint Prep - this will increase adhesion by 3 times. For grilles with carbon fiber (for example, on AMG models) use epoxy glue J-B Weld PlasticWeld with fiberglass reinforcement.

How much does professional grill repair cost?

Prices at car services depend on the type of damage:

  • 💰 Soldering a plastic grill: 1,500–3,000 ₽.
  • 💰 Argon welding of aluminum: 3,000–6,000 ₽.
  • 💰 Straightening + painting: 4,000–8,000 ₽.
  • 💰 Chrome restoration: 5,000–10,000 ₽ (depending on the area).

For comparison: the new grille on Toyota Camry costs 8,000–15,000 ₽, for BMW 5 Series — 15 000–30 000 ₽.

Is it possible to paint the grille without removing it from the car?

Technically it is possible, but the quality will be lower: it is difficult to ensure uniform coverage and protect adjacent parts. If you decide to paint on site:

  1. Tape the bumper and hood masking tape and film.
  2. Use aerosol cans with a narrow nozzle (for example, Motip Spray Gun).
  3. Apply paint to 3 thin layers with an interval of 5 minutes.
  4. For drying use construction hair dryer (temperature not higher than +60°C).

Disadvantages of this approach: the risk of smudges on vertical surfaces and incomplete coverage of hard-to-reach places.

How to protect the grating from corrosion after welding?

After welding steel or aluminum grating:

  1. Clean the seam metal brush and degrease.
  2. Apply acid soil (for example, Reoflex Wash Primer) for passivation.
  3. Paint epoxy primer (2 layers) and acrylic enamel.
  4. For aluminum use anodic coating (for example, Alodine 1200) before painting.

For added protection, apply anti-gravel coating (for example, 3M Scotchgard) to the back of the grille.