Old timer at a shop in Denver told me to never use body filler over bare metal

Back when I was first starting out around 15 years ago, an older guy named Hank at the shop I worked at in Denver said to always use epoxy primer first before any filler. I got in a hurry on a quarter panel last week, skipped it, and the filler is already starting to bubble up in the humidity. He was right. Anyone else learn that lesson the hard way?

3 comments

3 Comments

caleb_stone1mo ago

@terry_lewis21 nailed it about moisture getting trapped. The epoxy primer is basically a moisture barrier that lets the filler bond right, and skipping it is like paving over mud. Old Hank knew that metal needs that seal or humidity finds its way in every time.

hayes.jake1mo ago

Reminds me of the time I painted a shed in July and forgot to check the humidity once.

terry_lewis211mo ago

Used to think the old guys were just set in their ways but Hank was right about everything. I did a fender patch on my own truck without epoxy primer once and had rust starting through the filler within a year. The moisture gets trapped between the metal and the filler and there's nowhere for it to go. Now I never skip that step even on quick jobs.