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Body Filler over SPI Epoxy

I know this has been discussed in the past, but Iwant to lay out how I am fixing to try this, and want to make sure I am following proper procedure. I stripped the panels to bare metal, 80 grit them thoroughly, and the main areas I will have to be spreading filler, I even ground with a 36 grit disc. I will be skimming much of these panels with a light coat of filler also, because this car is just plain rough. That is the only way i can get them straight. Anyway, after 80 grit DA and grinding, I blew tthe panels off and wiped them down with SPI Waterborne grease n wax. and let that sit a day (due to some areas having lead in them). Two coats of epoxy (unreduced and the 30 minute induction period done). I waited half hour at least in between epoxy coats. I understand I have 7 days to get my filler on these panels, or i would need to just 180 them and then apply my filler to them. I was going to wait at least 48 hours to insure the epoxy is dry. My concern is is there enough bite to just spread filler over epoxy now? I am assuming the epoxy down on the clean, properly prepped bare metal took care of that, but I've never filled over epoxy. For the most part I have always done my bodywork on clean prepped bare metal. I am using 3M Platinum Plus filler. Is it then a chemical adhesion going over the epoxy with the filler? I know after all filler work is done, I need to re-epoxy areas that show bare metal and move forward. Does this all sound correct? If I am outside the seven day, just 180 and apply another coat of epoxy? Sorry for the long post, just want to make sure i am following proper procedures.


Paint Fanatic
Staff member
Perfect Prep!!!
Up to 7 days just walk up and spread the filler or glazing putty over the epoxy.
If you go over hand sand spot with 180 before applying.
Sorry to bring this back, but I want to make sure I have got it right. Once I spray 2 coats of SPI epoxy primer onto the bare metal with an 80 grit DA scratch, I can apply body filler over (unscuffed) epoxy primer 24 hours after spraying but not after 7 days without re-sanding. Is that right?