Minor dents are perfectly suited for non-intrusive dent repair
. Working from the backside of the dent, a trained technician can gently work the metal outward using plastic-tipped punches. When the process is completed the dent completely disappears without the need for body fillers or paint. Such dent repairs are less expensive than traditional bodywork methods. The technicians often perform these repairs in the car owner's driveway or garage, eliminating the inconvenience of dropping off the vehicle and arranging alternative transportation. If the dent is deeper or has caused permanent distortion of the surrounding metal, the repair will become much more intrusive, time-consuming and expensive. Such dents and damaged areas must be forced back outward by using a hammer and dolly to slowly move the metal back into shape and nearly flush with the surrounding surface. When it is difficult to gain access to the backside of a dent, or when the backside of the dent may be difficult to reach using a dolly, a small hole in the center of a dent is drilled for a bolt to be attached or to a pin welder is used to tack a pin or series of pins to the damaged surface. Using a slide-hammer attached to the bolt or pins, the dent is pulled outward until it is nearly flush with the surrounding surface. After the dent has been pulled outward, the remainder of the dent repair is performed using plastic or resin body fillers applied in thin layers over the remaining dent until the surface is built up to the level of the surrounding surface. The body filler is sanded down using very coarse and fine sandpapers until the profile is correct and the body filler flows perfectly with the surrounding surface. Finally, the area must be primed and painted to match the rest of the vehicle.