Hi, I'm boxing in the under side of my panel truck from the floor to the bottom of the fenders on the rear section. I've got all the panels made and I'm going to paint them before I weld them in but was wondering if I should use a rust encapsulator paint or epoxy primer, I have both but don't have the best of ventilation and it is definitely too cold, -35f to open the doors of my shop. This is fresh clean metal that I will be painting.

John

 

I would use a weld-through primer for that application on the to-be-hidden side. Then, after welding I would coat the underside with an undercoating or herculiner.

 

Herculiner is an interesting idea. You mentioned that your painting, I would use a metal wash followed by a self etching primer for bare metal. If you arent going to paint it soon, then shoot an additional epoxy primer coat on top.

 

This is my third attempt to reply and thank you for your input,the web browser keeps losing this site. I decided this morning to go with the epoxy primer, I won't be in the shop for a few days so I hope that most of the fumes will be gone by then. Thanks again and I'll try and keep you all informed of my progress, I received shipment of my front fenders,gravel pan and air deflectors yesterday, so all I need now is a set of running boards to complete all the body parts which will only leave me about a light year to complete my panel. John