My 15 Silverado had all kinds of rust. It is normal

 

Ford has had a better anti-corrosion process than GM for the frames since 2000. Ford e-coats the frames and GM still uses the old wax that wears off. I have Fords here in the North that are 10 years old and the frames are still like new. My spare plow truck 2008 2500 Chevy is almost ready to crack in half by comparison, it’s rusty and crusty. The Ford of same age paint hasn’t worn off yet.

 

In Colorado our lack of humidity may leave your skin dry and your lips chapped but at least we see very little undercarriage rust.

 

I painted my rear end of my truck when it was brand new, before it even rusted. Now almost a year old and not a spot of rust on the rear.

 

Normal...

I painted everything under my truck with Rustoleum Bed Liner, after first hitting all the rusty things with Rust Converter. No problems since.

 

POR 15 is amazing. I have an old DeSoto I sandblasted the frame and painted it with POR 15 in 1992. I can’t find or see the slightest bit of surface rust on anything. I painted my 2016 F150 all over the frame in very salty conditions and not one bit of rust anywhere. Bill Hirsch who started selling this paint used to salt spray frames and leave them out to rust and they never even began to rust. Two caveats, the paint will degrade some in direct sunlight and if you get it on you there is only one solvent and if it dries on you it Is on you for weeks no matter what you try to get it off.
Great stuff!