Finished today with the cross beam of the frame beneath the engine. For anyone interested in doing this, you need the following:

POR-15 (silver or gray)
60/150/400 grit sandpaper
Sanding block
Chisel/Screwdriver/something to scrape
Paint brush
Krylon Smoke Gray
Optional but recommended (mask/safety glasses/gloves)

Sand down and chip away loose epoxy from the rusted areas, use something and scrape in around the hardened epoxy as some will chip off and will get you a better surface to prep/paint. Sand down all rusted areas and try to blend epoxy down into bare frame. Follow POR-15 instructions with prepping and cleaning surface, paint. Go over with 400 grit sandpaper and grind down any bubbles or drips. Spray over with Krylon paint.

Here are some pictures of the frame after the POR-15 and before the Krylon paint:






For the hole in the first picture, this is drainage and the whole area is hollow, you can see through it from either side of the car behind the wheel. I had some rust up in here so I scraped whatever I could reach, and as I couldn't see where I was painting in there with POR-15 I bought Rustoleum Smoke Gray paint also and plugged one end while I sprayed lots of paint in from the other end.

Here are some before and after pictures:











Altogether I am happy with how it came out. I am sure you can make it look more stock/flat if you really sand it down flush. For me it was hard as I had the car on jack stands and wanted to touch up and stop the rust that was already there. The Krylon Smoke Gray paint does not match perfectly, its a bit darker gray, but I am sure after it gets dirty again you won't be able to tell the difference.