How to find Bondo repair

[Frog76S]

I have an ascot green 76S Targa barn find. Rennbow indicates ascot green is a rare color, a five by their rating method. I prefer coupes, but kept the targa because I like the unique color. I have many receipts with the car and it appears there were a few fender benders.

How can I find bondo on the car? I’ve gone over the car with a magnet thinking it won’t cling to bondo, is that correct? What’s the best way to find bondo without stripping the paint?

Thanks!

[drcoastline]

A magnet will work, there are also other methods such as a digital coating thickness tester.

Obviously a magnet has less attraction as a coating gets thicker. This could be bondo, paint or some other non metalic substance between the magnet and the steel. Digital meters work on a similar principal.

[76dno]

Strip it - that’s the only way to achieve true peace of mind. And if/when you do strip it, document with many many pictures so if/when you sell the car, you can show to prospective buyers.

[pkabush]

You’re on the right track. Bondo or any plastic filler for that matter is of course non ferrous.
Even if it was put on rellhitivly thin you’ll feel the difference with a good magnet.

[Marine Blue]

As noted earlier, a paint meter would be a good way to establish paint thickness as well as bondo and its thickness. Basically a paint meter is measuring the distance between the meter and the base metal so if for example the meter reads 25 mils then you likely have about 5 - 7 mils of paint and another 18-20 mils of bondo/filler.