Help with Grinding wheel for angle grinder....what kind?

gdizzle said
I have a 4in wheel grinder that I am getting ready to put to work on a few rust areas on my 66 dart. Mainly the rear quarter panel near the bottom, and also the roof seam.

The rear quarter panel has developed a bunch or pimple/blisters and i believe they have already been bondo'd, painted and now it is breaking out again. I want to be careful that my grinder doesnt just eat through the fender like butter.

The roof seam looks to be just rusted at the seam, old seam sealer is all breaking apart.
What type of grinder disc do I use for this type of body work?? Keep in mind I have never done grinding on a car before, so this is my Maiden Voyage.
I also have an orbital sander if that is safer? Thanks for any help you guys.
My current plan is to prep the car best I can, then take it to a MAACO and just have them spray it with their best 2 stage paint.

I have to agree on the flap disc, and really have to agree about the heat they generate.
Just take your time and don't stay on one spot very long at a time.

Sometimes I do use a wire wheel, since it rips old bondo and garbage right off without doing more damage to the underlying metal.
Here's an example of what can be done in the back yard with a small compressor and no paint booth.
This is Acrylic Enamel single stage with "wet look" hardener.