Know-How Notes: What is Paintless Dent Repair (PDR)?
Paintless Dent Repair, or PDR, has been around for a very long time, but it has not always been considered a mainstream solution for body panel repair. There is a lot of mystery surrounding PDR and how it works, which has kept this process from being a readily accepted repair process until the insurance industry found that it the best and cheapest solution for hail damage. PDR was invented in 1960 during the New York Auto Show as a way to repair dents and dings in new cars from spectators. Over the next 50 years, the process was refined and became the go-to solution for small dent repairs.
Unlike typical body work, PDR does not require paint or body filler. The process uses picks and bumping hammers to slowly work out dents and dings, similar to the metalworking process used to form sheet metal before mass production (which is still used today for custom work and repairs). While it looks easy (it looks so simple), it is actually quite difficult and takes a lot of skill to properly work a dent back into the original form.
Any time metal gets dented, it stretches. In order to remove the dent, it has to be shrunk, this requires a deft hand and lots of training. PDR techs go to school to learn this trade, and they spend years mastering it. To watch a skilled PDR man work is truly entertaining and impressive.
One of the hardest parts of the PDR job is finding all the dents. Long fluorescent lights on adjustable stands are used to highlight the flat surfaces of the body so that the tech can see the dents. Each dent is marked with a grease pencil or piece of tape to they can track it. It is not uncommon for a PDR tech to work over 100 hail dings in a single panel, so you can imagine how important marking each one is.
The tools of the trade are pretty unique. The picks are long hardened rods with different bends and tip shapes to help get into the area to be worked. In most cases, they can work a roof dent without removing the headliner, just taking it loose gives them the access they need. Sometimes a hole may have to be drilled in substructure, but nothing visible. It usually takes a few presses to get the dent pushed out. If pushed too far, the dent will become a raised area, which is just as bad, so the PDR tech will work slowly to get the dent smooth.
Once the dent is out, it may be raised a little. If this happens, the tech uses a bumping hammer and small hand-held pick to lower the raised area. This also recreates the factory orange peel in the paint that it usually present. Often, these tools are homemade or modified by the tech to suit their style or needs.
Some dents are not accessible or reasonable to use a bumping pick. Instead, these dents are pulled with a specialty tool. Using different sized nylon plugs that are glued to the body with paint-sensitive hot glue, small dents and dings can be removed without much effort. This works really well in areas where there is a lot of flex in the main panel or close to sharp body lines or edges where a pick can’t reach.
Using these pullers, there is often a little more paint damage, nothing serious, but scratches certainly occur. Any scratches are lightly sanded out using 1,500 to 3,000 grit sanding blocks, and then the area is buffed with a small buffing wheel to bring back the shine.
PDR is an impressive process, but one that is for the experts like those at your local NAPA AutoCare Collision Center. Attempting this on your own vehicle without any training is not going to turn out like a professional PDR tech, and could actually make things worse, requiring a full paint and body repair. Keep that in mind if you are keen to try it on your own. If you do decide to try this process, it is highly recommended that you practice on scrap metal first.
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