Regardless of whether you have a fresh-off-the-lot new car that has suffered an accident, or you have purchased a used car and just want to spruce up the body, removing large dents at home can save you a lot of money in repair and bodywork bills. Removing large, unsightly dents is fairly straightforward and can be accomplished by any home mechanic with a bit of patience and ingenuity.
Begin by determining which dents can be removed with the suction dent puller and which ones will require the screw-in dent puller. The suction dent puller is good for large dents in flat surfaces such as the hood or side panel, whereas the screw-in dent puller should be used for dents with a crease or on concave body panels.
Use the suction dent puller to remove all of the dents that can be pulled by this method. Find the centre of each dent, place the puller on the centre, flip the handle, and then firmly pull outward to pop the dent out. You should not need to use any putty on these dents.
Move on to the dents that require the screw-in dent puller. Use the drill to drill small (3mm (1/8 inch) in diameter) holes at 75mm to 100mm (three- to four-inch) intervals along the crease of the dent. Screw the threaded adaptor into one of the holes you just drilled and then forcefully slide the handle of the dent puller away from the car. Repeat this process for each hole you drilled to pull the dent out of the panel.
Mix up some body putty and then cover the holes and any remaining small dents with it. Try to keep the putty as thin as possible when spreading it so as to make it easier to sand down. Allow the putty to completely cure and then sand smooth with the sandpaper. You can now have the body panels painted or drive the car as it is.
Remove as many dents as you can with the suction dent puller as there is less prep/finish work involved with this method than the screw in method.
Do not pull on the screw in dent puller too forcefully as you could end up stripping out the panel hole and making the panel look worse than it did before.