As many of us have experienced, I just had a "detour" in my project. Just a brief background: When I started the tear down almost 5 years ago....yes I know....a LONG TIME, I had NO clue as to what process or products to use for all the body work. A local jobber was great help in getting me started; however, I think I got some "dated" advice from him. I started off by stripping the car to bare metal and was going to shoot etch primer over the filler work...per his advice. Somewhere along the line, I found out about epoxy primer, but not about SPI. The jobber sold me a "sort of" epoxy, which was "Corlar mastic" by Dupont. As I found out later, this is actually an industrial coating used on OIL RIGS! I sprayed this stuff OVER the filler work, and although it was a PIA to spray, it covered fairly well. Well fast forward, and I found SPI and have been VERY happy with their products and customer service. After much soul searching, I decided to strip the Dupont stuff, and re-shoot SPI epoxy. With the exception of the BC, all the products on my car will be SPI, and I wanted to keep it consistent. As I was stripping the old epoxy, I realized I had done filler work on the bare metal. I know this is a time-proven way, and many folks still do it that way. However, for me (and per SPI) doing the filler work over two coats of epoxy makes more sense. As I was sanding, I could swear I saw what appeared to be rust under some of the filler that I hit with the DA by mistake. By the time I could look, the DA had hit what might have been slight rust, so I am not 100% sure. This brought a nagging thought into my mind, and I kept second-guessing myself as to what quality of work I did with the filler back then. Don't get me wrong, I don't know squat now (just enough to be dangerous) but a WHOLE LOT more than back then. I hate the thought of stripping all the filler work that I did back then, but this brings me to my question.....which if I am asking....I think I already know the answer. Since I am down to stripping to bare metal anyway, should I just remove all the filler? Shoot 2 coats of epoxy and re-do all the filler work on top of that? Oh, BTW, there is some more filler on both lower quarters still covered by the old epoxy. Any thoughts/advice/insight would be REALLY appreciated!