Help Needed: Identifying White Spots on Frame

Hello - I've been traveling this past year so I parked my truck in a family member's garage for storage. Garage is in good shape but in a very humid area overall. There is definitely some existing rust but I have been quick with the fluid film and wire brushes to keep the frame in generally good shape. Truck is near and dear to my heart - been on countless adventures with bulletproof reliability.

Recently inspected the truck and found these white spots around the underside of the front portion of the frame. Barely any spots on the frame past the front wheels. Can someone help identify what these spots are? Rust, etc?

I took my finger to the white spots and they rubbed off easily - they appear to be above the actual fluid film coating. I'm a bit nervous and am prepared to pull the truck out of the garage asap if this is a sign of degradation.

Thanks in advance.

 

I’d guess mold. Spray a little bleach in a few spots to test

 

Does it feel gritty, like maybe dried up salt? In an area that salts the roads?

 

Looks like road salt that’s dried.

 

mold growing on the lanolin that's an ingredient in fluid film.

 

I agree, looks like mold. The bleach test will tell you for certain.