How to Use Putty to Fix Dents and Scratches in Your Car

How to Use Putty to Fix Dents and Scratches in Your Car

If you have a small ding or scratch, or if you've hammered a larger dent back into a reasonable approximation of its original shape, it's time to smooth over the affected section with putty. You will end up with a somewhat unsightly patch—see How to Paint Repair a Car, to get your paint job back in tip-top shape.

TOOLS:

• Wire brush, orbital sander, or sanding disk attached to a drill

• Rags

• 2-inch putty knife

• Smooth-grain sandpaper

MATERIALS:

• Rubbing alcohol

• Auto body putty (such as Bondo)

• Scrap cardboard

1 Clean the surface. Start by removing any rust around the ding or scratch with a wire brush, orbital sander, or sanding disk in a drill, then clean the area with alcohol.

How to Use Putty to Fix Dents and Scratches in Your Car

2 Apply putty. The brand name Bondo is synonymous with auto body dent repair, though other kinds of putty exist (and Bondo's parent company, 3M, sells a nice dent-repair kit that includes putty and all other needed supplies). To use Bondo, mix the putty with the bonding catalyst (following package instructions) on a piece of scrap cardboard. Make sure no leaves or dog hair have floated into your clean dent while you weren't looking, and then use a putty knife to spread Bondo over the dent. If you're repairing a rusted-out section of panel, apply the putty to the front and back of the panel until you've built an appropriate base. The more the putty overflows the dimensions of the dent, the more sanding you'll have to do later—but better too much than too little.

How to Use Putty to Fix Dents and Scratches in Your Car

3 Dry the patch. If it's a sunny day, park the car with the repair in the sun to dry. If not, consider pointing a heat lamp or hair dryer at the patch. Dry for at least 30 minutes and run your hand over the patch to check that it's not still tacky. Sand the patch with smooth-grain sandpaper until it's smooth with the body panel, then repaint as needed (see How to Paint Repair a Car).

How to Use Putty to Fix Dents and Scratches in Your Car

SANDING A SCRATCH

If you see a scratch in your car's paint, make sure that it isn't just something stuck to the outside of the panel—run your fingernail over the mark to see if it has depth. If your fingernail doesn't catch on the scratch, that means you have a scratch in your car's clear coat that doesn't extend down through the paint. Instead of filling the scratch, you can simply hide it by sanding down the surrounding finish to the level of the base of the scratch. Start by rubbing something into the scratch that contrasts with the car's paint color—shoe polish or Wite-Out work well. Now you'll gently sand the scratched area with very fine, 2,000-grit wet sandpaper until the shoe polish or other material disappears, at which point you'll know you've reached the base of the scratch. While sanding, pour ample water over the scratched area. Polish with rubbing compound and then finish with wax.

YOU MAY ALSO LIKE