Technical filler over epoxy, how soon?

I have always put filler over bare metal, I will NEVER GO BOTH WAYS!

 

If you do a light swipe, a minor correction feathered really thin, you won't see an issue. Of course in over 40 years of this shit I've had filler over some form of primer. But to prime and then do general fill work up to 1/16th thick, it can cause softening of the epoxy. Once that beautiful finish gets heated up at the carshow when it's 85-90 degrees in the hot sun, that soft epoxy will show itself by swelling around your fill. Again, a really light whispy glaze, probably never. Not enough trapped poly solvents working away at the epoxy below. I like epoxy to seal the filler work before final prime. That fill is porous, it sucks up solvents too. An easy coating of epoxy is a great defense against solvent penetration. Solvent penetration. Solvent penetration. I said it 3 times to hammer home the biggest failure point in custom finishing. ALL OF THIS STUFF has it's own solvents in them and they don't all like each other. Every chance you have to reduce, here it comes again, solvent penetration is a good step for longevity and quality. Epoxy is a great barrier but it isn't 100% immune. And also, some may not ever see where that epoxy swells up, or at least not for a few months after. Maybe that 1st re-wax or detail long after it's done generating a huge "WTF IS THAT!?!" No thanks...

 

Running the body shop the only problem I ever had was as you stated HL was a young body guy that would rush painting over the primer after putting the primer on too thick is solvent pop, as what we called it. Luckily he just did a couple small jobs and he learned immediately the error of his ways.

Yeah the pits I'm working with are many but very small, none over 1/16 deep, 90% just surface visual.

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My fenders were a bit rough and pitted on my PU. After welding up the rips and boogers and pounding on them until my arms hurt I had them sandblasted then I applied epoxy primer to the outsides and rhinoliner to the insides. Then I shot them in polyester primer (it is not DTM so the epoxy step was necessary). I had to recoat them in polyester primer after the initial block sand, but the second coat provided good results.

I am not a painter or body guy. If you had seen what I started with you never would have thought they would be this flat.

 

a work of ART !!! the Lake Pipes are 'Bitchen"

 

@Bandit Billy that's beautiful!

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Thanks boys. All I can say is don't be in a hurry or trying to do one of those stupid TV car show paint jobs in a day or two. I could have been faster than 2 years, but the results were good, less expensive and very satisfying.