Prime & Paint underside questions

Hi,

My first choice would be epoxy primer on any clean, bare metal. The EDP you have on replacement panels is a real crap shoot depending on the conditions it was applied under. Almost all the reproduction panels are coming out of China and the EDP ranges from good to applied over rust, grease and dirt. Striping it off and applying a good epoxy primer is always a safe move.

For the other areas , I like the idea of media blasting sections at a time and putting it in epoxy primer. Epoxy primer covered with a urethane based truck bed liner material as an undercoating is a very good system.

Some people get good results with POR 15 others don't. I'll leave it to people who have experience with it to add they're opinions.

Etching primers are used where speed of the repair is a factor, epoxy primers are better for restoration projects. Epoxy primers are the only primers that are truly water proof. All the major paint suppliers like PPG make decent epoxy primers. Southern Polyurethane Inc. (SPI) makes a very good epoxy primer for a little less money than the majors and the tech. support is excellent. SPI is what I use.