How to Straighten Metalby Don Kress
The process of straightening metal is one that, while seeming easy, is actually a fairly difficult thing to do correctly. The reason for this is that metal tends to stretch when it is bent. In order to counteract this stretch, you have to be able to shrink the metal back to its original position. With practice, however, you can learn to straighten metal so it is very difficult, if not impossible to tell that the metal was ever dented in the first place.
Remove any plastic trim from the metal that requires straightening. Any paint on the surface of the metal will crack and flake off when it is bent, but plastic trim may make straightening the metal more difficult.
Place the dolly on the concave side of the dent or bend. You will be using the metalworking hammer on the convex side. The dolly is used to prevent the hammer from pushing the metal too far out of place. The ideal situation is to return the metal to exactly its original position. Using a hammer specially designed for straightening metal also helps to shrink the metal back into position.
Strike the convex side of the dent or bend with the face of the metalworking hammer until the dent appears to be straightened.
Wrap the sandpaper around the sanding block, and then use it to sand the surface of the metal. This will show you any high or low spots that may have occurred. When you can clearly see the high and low spots, use the hammer and dolly again to straighten them out.
Sand the surface again and continue straightening the high and low spots with the hammer and dolly until the entire repair area is completely smooth.
- "Collision Repair and Refinishing: A Foundation Course for Technicians"; Alfred Thomas; 2009
- "Automotive Bodywork & Rust Repair"; Matt Joseph; 2009
- "Pro Paint & Body"; Jim Richardson; 2002
- This process also works for straightening out plate metal that has become dented or bent. Unfortunately, metal that has kinked, such as is common on bent metal tubes, cannot be straightened, but must be replaced, as the kinks will significantly weaken the metal.
Things You'll Need
- Metalworking hammers
- Sanding block
Don Kress began writing professionally in 2006, specializing in automotive technology for various websites. An Automotive Service Excellence (ASE) certified technician since 2003, he has worked as a painter and currently owns his own automotive service business in Georgia. Kress attended the University of Akron, Ohio, earning an associate degree in business management in 2000.