Getting ready to paint frame and axles next week with por 15 how much would be needed you think. The stuff is little pricey compared to rustoleum so don't want to over order

 

That's because comparing Rustoleum to POR-15 is like comparing chrome spray paint to Chrome plating.

 

I would really like to paint the frame, axles, etc. of my 2001 Excursion with POR-15. However, given that it is not remotely practical to strip it down to the frame and sandblast it, I know that there will be places that are unreachable to be painted. My concern is that this will allow rust to get a start in an uncovered area and work its way under the paint. I figure if that happens I'd eventually need to strip the area and repaint it, but that's probably near impossible with POR.

Am I being paranoid or would it be better off to go with something like Rustoleum's rust preventer that would be easier to scrape down and reapply if needed in the future?

Also, I noticed that there is some rust beginning to form around the body seam where the running boards attach. What is the best way to clean and seal that before it gets out of hand?

 

Rhino skin undercoat works great and works great so I hear.
Good luck

 

Check out this thread. There are some answers for what I used.
https://www.ford-trucks.com/forums/1...oration-5.html

 

I have used Rust Encapsulator and Red Rustoleum. Both work well and prep is similar. Clean/de grease/pressure wash (or steam clean), Remove any loose rust or scale and prime. I just did a '79 F250 frame this way. After cleaning, I used a needle scaler to remove loose rust, red rustoleum primer and SG black rustoleum finish coat. The red rustoleum is less costly than rust encapsulator and takes longer to dry. Both are great products.