Technician sanding a repaired dent

Deep Dent Repair

Explore precise repair methods for deep dent repair on state of the art substrates with 3M™ FC Epoxy Metal Filler.

Common methods for deep dent repair can lead to defects and pinholes in modern steel substrates.

Levelling a dent by pulling it often leads to micro pin holes or overstretching of the thin steel. To seal any surface defects, a non-hygroscopic filler should be used to prevent moisture penerating into the metall and causing corrosion.

  • Technician using equipment to pull dent
    • Precise grinding tools such as Festool Automotive Systems Geared Eccentric Sander ROTEX in combination with 3M™ Cubitron™ II Abrasives allow less standing steps with a better finish due to finer grids being used.

      Using 3M™ FC Epoxy Metall Filler provides you with a non-hygroscopic filler with great adhesion to aluminium, steel and galvanised steel, which is able to seal any micro defects.

      Click the play button in the image to watch the video

      Download Deep Dent Repair Process Brochure (PDF, 500KB)

      Contact a 3M expert

Products to repair a deep dent

Discover our range of damaged panel removal products to help achieve high quality, efficient repairs in your bodyshop.


How to remove a deep dent from a car panel

Step-by-step process guide to repair a deep dent in a car body panel

  • Pre sanding a deep dent

    Step 1 - Pre sanding of the damaged area

  • Technician preparing surface for dent pulling

    Step 2 - Surface preparation

  • Technician is spot welding in preparation for dent pulling

    Step 3 - Spot application

      • Spot weld onto the repair area using your preferred and recommended method and/or equipment

      Note: Always ensure that the equipment properly calibrated depending on the materials being repaired.

  • Technician using equipment to pull dent

    Step 4 - Dent pulling

      • Pull the spots of dent using preferred dent pulling method and equipment

      Tip: To avoid surface imperfections or pinholes in the substrate, aim to distribute the load across the repair area.

  • Technician using spot removal method

    Step 5 - Spot removal

      • Spot removal by rotate the welded spot manually

      Note: This modern method will reduce the likelihood of causing holes in the substrate and avoid the thin out of the substrate due to a coarse sanding step for the removal.

  • Technician is sanding down the area to the bare metal

    Step 6 - Sanding down the job area

  • 3M™ General Purpose Adhesive Cleaner

    Step 7 - Cleaning of the surface

  • Technician is applying 3M™ FC Epoxy Metal Filler for dent filling

    Step 8 - Application

      • Apply enough 3M™ FC Epoxy Metal Filler for dent filling
      • Recomended settings for applicators: pneumatic max. inlet pressure 5.5 bar / battery driven 3kN, max speed 180mm/min

      Note: A new cartridge needs to be equalised before the first application to ensure thorough mixing of the product. After the first use, no futher equalisation is necessary.

      Recommended products:

      3M™ FC Epoxy Metal Filler

      3M™ Static Mixing Nozzle

      3M™ Plastic Spreader

  • Technician is using IR drying to increase speed of drying

    Step 9 - Drying

      • The curing of 3M™ FC Epoxy Metal Filler can be accelerated using IR drying after the initial gelling period. Wait 10 minutes before using an IR dryer to heat for 10-20 minutes with a panel temperature of 70°C
      • Airdying: sandable ~ 4 h @ 22°C ambient temperatures

      Tip for use: warming up the material & surface to ~30°C before material application will help to accelerate curing, particularly at cold ambient temperatures.

  • Technician is sanding the filler area

    Step 10 - Sanding of the filler area

  • Technician is cleaning the surface to ensure no dust or grease is apparent

    Step 11 - Cleaning of the surface

  • Technician is applying a second layer of 3M™ FC Epoxy Metal Filler for dent filling

    Optional - Second layer application

      • Apply a further layer of 3M™ FC Epoxy Metal Filler if nessessary and repeat drying and sanding steps as recomended in the previous steps
      • Maximum finished thickness should not exceed 4-6 mm, maximum layer thickness should not exceed 2-3 mm
      • Follow OEM and paint company recommendations for subsequent steps

      Recommended products:

      3M™ FC Epoxy Metal Filler

      3M™ Static Mixing Nozzle


Technical tips for removing a deep dent from a car panel

Here are some valuable insights into specific challenges surrounding repairing deep dents on car panels, including quick tips on preventing common issues such as....

  • Customer Challenge:
    Common methods for deep dent repairs can lead to defects and pinholes in modern steels and substrates, which are made these days from thinner sheet panels.


    Technical Tip:
    Welding equipment must be properly calibrated to avoid too much heat entrapment. Distribute the energy load across the whole repair area during pulling, to avoid any holes and overstretching of the substrate.

  • Customer Challenge:
    The repair of damaged sheets of modern steels and high-strength steels in the outer skin of a vehicle can be problematic, because of their very special properties. Those types of steel are sensitive to thermal stress, which can negatively impact on the hardening properties of the steel.


    Technical Tip:
    Avoid introducing heat into the grinding process by using precise grinding tools such as Festool Automotive Systems Geared Eccentric Sander ROTEX in combination with 3M™ Cubitron™ II Abrasives Disc. This generates a better finish due to changed grain recommendation, reduced repair size and a better quality of the dent repair "from the start" with the goal of maintaining structural rigidity.

  • Customer Challenge:
    Polyester resin fillers usually have less adhesion and worse mechanical properties than epoxy resin based products. Polyester fillers have hygroscopic properties and absorb water, which can lead to long term corrosion and delamination.


    Technical Tip:
    Using 3M™ FC Epoxy Metal Filler provides you with a non-hygroscopic filler with great adhesion to aluminium, steel and galvanised steel, which is able to seal any micro defects.


Discover more from 3M

  • Haven't found what you're looking for? Or perhaps you would like to arrange a demonstration? Click here to get in touch!

  • Remember to always select appropriate Personal Protective Equipment - Eyewear, gloves, hearing and respiratory protection for your job and workplace!

  • We don't just have solutions for removing dents from a car panel. See our extensive range of solutions for all your car repair needs!


Ask a Collision Repair Expert
  • Thank you for your request to 3M. The information you provide on this form will be used to respond to your request through email or telephone by a 3M representative or by one of our authorised business partners with whom we might share your personal information consistent with the 3M privacy policy

  • All fields are required unless indicated optional

  •  
  •  
  •  

  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  • 3M takes your privacy seriously. 3M and its authorized third parties will use the information you provided in accordance with our Privacy Policy to send you communications which may include promotions, product information and service offers. Please be aware that this information may be stored on a server located in the U.S. If you do not consent to this use of your personal information, please do not use this system.

  • Submit Submit

Thank you very much for your request.

A Collision Repair Expert will contact you as soon as possible.

Our Apologies...

An error has occurred while submitting. Please try again later...