Warning: Stop using filler on deep dents without checking the backside first

I keep seeing guys at my shop in Detroit slathering filler on dents that clearly need pulling from the back. Last month I had a 2018 F-150 come in where someone already packed an inch of filler onto a quarter panel. It cracked after three months of Michigan road salt. How is that supposed to hold up when you skip the metal straightening? I spend an extra 20 minutes per panel getting it straight before filler touches it. Has anyone else dealt with come backs from this shortcut?

3 comments

3 Comments

blair_butler4713d ago

Whoa, hold on. I gotta push back on this pretty hard. Checking the backside before you start pulling dents is the difference between a job that lasts 10 years and a job that comes back in the spring. Yeah, the F-150 has seam sealer back there, but that's exactly the point - if you don't dig it out and see if the metal is stretched or cracked underneath, you're basically painting over a ticking time bomb. I've seen guys skip this step, slap on a thick coat of filler, and then watch it pop right off when the car flexes over a pothole. It doesn't matter how good your primer is if the metal underneath is still oil canned or has a hidden stress crack. You might save 20 minutes now, but you'll eat two hours fixing your own work if that filler decides to let go.

jade61813d ago

Did you check the backside before adding that filler on the F-150?

josephb3513d ago

Check the backside before welding filler? Nah, I think you're overthinking it a bit. On these newer F-150s the backside is usually covered in seam sealer or already has a coating from the factory. I've repaired a few of these and never had an issue just working from the front if you clean the area good and use a quality filler. The key is getting the metal 100% clean and using a self etching primer first. Seems like a waste of time to flip the panel around unless you're doing something major back there.