I've got an 87 GT that I'm looking to restore. It's factory red, but I want to change the color to a dark blue (Impluse Blue from the mid 2000s GTOs). I started sanding today. Below the red was a black layer, below the black was smooth white. I'm not sure if the white is thick primer or fiberglass. How deep should I be going for this sanding job? There were some pretty deep scratches that got into the white, hence why I went so deep. I've never really done any serious paint/body work, so I would appreciate some advice.
[This message has been edited by Napoleon_Tanerite (edited 09-11-2015).]