[swamp rat]

Originally Posted by Vic1947

That's what most body shops do these days, although the seam sealer can be applied before or after 2K primer as desired. Some folks use epoxy primer in lieu of self etch, but you need to make sure the manufacturer is good with that approach. Epoxy has the advantage of completely sealing the metal away from the humidity in the air. Most other primers are somewhat porous and without a topcoat will eventually succumb to the elements and allow rust to form.

What you're trying to achieve is a multi-layer barrier that stands up to the environment. Back in the day, body men routinely ground down a damaged panel to bare metal, applied plastic filler and then primed and painted. As long as the underlying metal has no fractures that allow moisture to seep in from behind, this was a perfectly acceptable way to repair a panel. Over the years, the materials and the science have evolved and now most places apply an etching primer or epoxy over the bare metal before applying filler.

However, it's impossible to work the filler without removing the initial coat of primer and exposing the bare metal again. So if you want to add extra insurance against moisture if the surface won't be topcoated for quite a while, you can reapply the epoxy over the bare metal / bodywork and set it aside indefinitely. If you plan to paint in the near future, a quality 2K primer is all you need. It will adhere just fine to the bare spots and the surrounding self etch or epoxy as well as the filler. You'll end up reapplying the 2K as you block the surface down to the point it's ready for the basecoat and clear.

Hope this helps.

Vic everytime you post it helps! LOL!