I’ve been very interested in this argument for some time now and have done it both ways in the past. Conventional accident repair tends to be bare metal fill then prime.. resto is epoxy first. I’m looking to take on the novol for classic cars system when I do my next restoration which is epoxy first.
One point that I keep seeing.. when filler is applied it’s chemical reaction creates heat .. and also moisture.. this is one of the reasons I like the idea of filling to an epoxyed surface. I have ground off filler in the past to find surface rust caused by this and I doubt highly the moisture has travelled all the way through the filler from a damp environment .. that tends to cause micro blisters more than anything.
My advice would be to use a pre protection (novol) it’s over paintable .. get the panels as close as possible with pin pullers/ hammer and Dollie so only fine skims are necessary after epoxy. If you are going to fill to bare metal wear gloves and also make sure workshop is a good temperature / humidity and red pad panel after its finished to remove any corrosion before primer..
Good debate I’m still torn.. it depends on car and budget a lot of the time for me.
One point that I keep seeing.. when filler is applied it’s chemical reaction creates heat .. and also moisture.. this is one of the reasons I like the idea of filling to an epoxyed surface. I have ground off filler in the past to find surface rust caused by this and I doubt highly the moisture has travelled all the way through the filler from a damp environment .. that tends to cause micro blisters more than anything.
My advice would be to use a pre protection (novol) it’s over paintable .. get the panels as close as possible with pin pullers/ hammer and Dollie so only fine skims are necessary after epoxy. If you are going to fill to bare metal wear gloves and also make sure workshop is a good temperature / humidity and red pad panel after its finished to remove any corrosion before primer..
Good debate I’m still torn.. it depends on car and budget a lot of the time for me.