Auto Hobby:
How to fill a dent – Part 1
Cut repair costs by doing body work on small dents and gouges yourself. Be
patient, take your time, and you’ll be able to get results that will rival the work of a
professional body shop.
Gather:
Sandpaper (150 grit, 220 grit and wet/dry 400 grit)
Body filler (with hardener included in the kit)
Glazing (or spot) putty
Rigid plastic spreader
Flexible plastic spreader
Masking tape and large sheets of paper
Automotive primer
Spray water bottle
Step 1: Prepare the surface
Because body filler doesn’t stick well to paint, you’ll have to sand down to bare
metal before you fill your dent. Use a heavy grit sandpaper (150-grit) to remove
the paint fast. Don’t be concerned about the rough texture; you’ll be smoothing
everything out later. Remove the paint from at least 3” around the dent to do the
job right.
Step 2: Mix the filler
The most common brand of filler is Bondo, but other brands work similarly. You’ll
be mixing up a two-part epoxy by adding a cream hardener to a base filler.
Follow the package directions to mix the filler using a rigid plastic spreader. Mix it
up on a clean surface like cardboard. Since the filler won’t stick to plastic, many
people use an old plastic plate or Frisbee as a mixing tray. NOTE: The filler
hardens fast once you add the cream, so be ready to move onto the next step of
applying the filler once you mix. You’ll have up to about 5 minutes to work once
it’s mixed.
Step 3: Apply the filler
Working quickly but carefully, use the flexible plastic spreader to spread the filler
into the damaged area and 3 inches around it. It’s OK to be a bit uneven because
you’ll be sanding everything once the filler hardens.
Now, let the filler dry. Check the package directions for drying times and signs
that you’re ready for the next steps, outlined in Part 2 of this story.
How to fill a dent – Part 2
In Part 1 of this story, you learned how to prepare and fill your automobile’s dent
or gouge. Now that the filler is in place and dry, it’s time to finish the job.
Step 4: Sand the filler
Wrap the 150-grit sandpaper around a rubber sanding block (or other block of
your choice). Sand the entire surface of the repair lightly, using broad, circular
strokes, going past the edge of the filler for a smother transition to the
surrounding undamaged area. If you see gaps or pits in the filled spot, mix more
filler and add it until you’re certain the area is filled. Of course, you’ll have to wait
for the new filler to dry again. That’s why this process requires patience. Once
you’re sure the filler is nearly smooth, use 220-grit sandpaper on the entire area,
continuing to sand until the area feels even and smooth. Remember, you’ll
eventually sand away most of the filler and will be left with a filled dent and a
smooth area.
Step 5: Glaze the area
Apply glaze (or spot) putty directly from the tube to the repair. This product will fill
in any tiny impressions remaining in the already sanded filler. Use a flexible
plastic spreader to smooth the glaze over the repair. Even though it dries faster
than the first putty you used, be sure it’s truly dry before you move to the next
step.
Step 6: More sanding
Lightly and evenly sand away the spot putty using 400-grit sandpaper until it’s
completely flat.
Step 7: Primer time
Before you use spray primer to seal and protect your repair, protect the rest of
your vehicle by masking off the repair area. Apply a spray primer in light, even
coats, avoiding all other areas (including tires). Remember, use light even coats,
not one heavy coat of primer.
Step 8: Primer’s last sand
After the coat of primer has completely dried, remove the masking tape and
paper from around the repair. Spray the repair area and the 400 grit wet/dry
sandpaper with water and sand the primer using a back and forth (not circular)
motion. Be sure to keep the area and the sandpaper wet as you work. If you see
metal, you’ve probably sanded away too much primer and you’ll have to prime
and sand again. Be thorough but be careful.
Step 9: Paint
Retail spray touchup paint rarely looks good on spot repairs. Use the money you
saved on the repair to get a professional paint job. It’s worth every penny.