How Dent Repair with Bondo Works vs. PDR

Bondo is a putty that traditional collision centers and auto body shops sometimes use to fill dents in a car. There are two ways to repair damage to a vehicle; one is with PDR when possible; the second is to use Bondo. Both hail damage and dents can be repaired with PDR or Bondo. 

The following steps are used by a body shop to fix a car with Bondo instead of paintless dent repair. 

  1. You clean the car and remove any residue or dirt from the vehicle. Starting with a clean surface is imperative.  Wax, bugs, tar, and dirt could compromise the adhesion of the Bondo and paint. 
  2. You sand the paint off the dented area. Tools to remove the paint are usually sandpaper and orbital. Ensure that the area that is damaged all the paint is removed. 
  3. Start working with a dent puller to remove part of the dent. This is very different than Paintless Dent Repair. A tab is welded to the panel and pulled from the outside in. The tab is then removed, and the panel sanded again. Mallets, Hammers, Picks, and slide hammers are used to reshape the panel to as close as they can get. 
  4. Bondo and body filler are now applied when the panel is reshaped. This filler is laid firmly, and there are chemicals used to ensure that the filler adheres appropriately. When the first layer dries, another is put on, and this process continues until the filler completely fills the entire remaining portion of the dent. 
  5. After the fillers are completely dry and the dent is full, you start to sand the dent down with a sanding block. This is a meticulous process; you go slow and steady to not over sand and have to start the process over again. If you do go too low, you may have to add more filler/Bondo and begin again. 
  6. The dent is sanded down, and then you sand it down with a finer grit abrasive sandpaper. This will ensure that the area is smooth and that there is a feather edge around the repair. This basically means that the rest of the edge blends in with the panel. 
  7. Next, you use the sanding block to remove the paint around the feather edge. This will ensure that the new paint adheres to this area and that it is smooth and ready for paint prep. All fine lines and scratches should be gone. 
  8. Once the feather edge is sanded out, you apply what is called a glaze and spot putty. This ensures a smooth finish and a smooth paint job. This is allowed to dry, and the sanding process starts again. 
  9. Repeat step 7 with finer grit sandpaper and then fill the panel again with the glaze. This process gets finer and finer until the glaze is perfectly level and ready to go to the paint booth for prep. 
  10. The car should have had all the necessary panels taken apart for paint before the Bondo work. The vehicle is now rolled into the paint booth for paint. When it is in the paint booth, the body shop tapes off any areas that will not be painted and covers your car so that overspray, or fine paint particles, are not covering your vehicle. 
  11. Paint is applied, baked, and then taken out for the final correction and polishing. 

Pros & Cons of Bondo vs. PDR

  1. PRO: Bondo, or acrylic skim, is necessary, sometimes. When you have cracked paint, structural damage, or dent that has no access to repair, the body shop is your answer! 
  2. CON: For hail damage, Bondo isn’t a necessity. You can fix hail by gaining access to the panel’s back or using an involved method called glue pulling to repair the area. 
  3. PRO: Body shops are an excellent repair method for conventional damage, like a car accident.
  4. CON: If large areas is repaired incorrectly, i.e., your roof and Bondo is used, and it is dented again, you will see your car cracked, but this time the Bondo will crack and split. Bondo needs to be used sparingly; the goal is always to use the least possible. 
  5. CON: Bondo has a shelf life; it can shrink and crack and pop out after years of being on your vehicle. 
  6. CON: You lose the original paint on your car, and this may devalue your vehicle. Check out this section on diminished value claims and CARFAX….

If you have questions about our repair process or Bondo or the best solution for your vehicle, because every car is different, you are always welcome to email us with any questions at or call us. Our number is 706-920-6836.

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