This will work right? i just bought two cans of it for tomorrow.

Does it matter what grit sandpaper I use to sand the metal and bondo to for this primer to stick the best? im guessing i'll sand the metal and bondo to about 120, then spray the primer, then sand it all down with 400 for paint??

THanks for the help, this should be the last of the questions. I am doing all the painting through next week. I'll post pictures when done!