Undercarriage question - fluid film/paint?

[socalmtbiker]

My undercarriage looks tired. Some surface rust and black paint is tired. I’m in SoCal and been researching fluid film vs just a rattle can on some parts. If you used FF, is there prep involved other than a clean surface? Is painting recommended prior?

 

[Kabanstva]

Just spray the FF everywhere

As long as it’s not muddy I would not bother prepping anything. That crap literally sticks to everything. Avoid exhaust and brakes

 

[Trunk Monkey]

Fluid film is meant to be a temporary barrier between metal and corrosives. For your area with little rust to worry about I'd just sand if needed to get some of the surface off and go to town with Krylon. But, realize it's going to look that way again in a few months.

 

[Sog]

I used Fluid Film, but as @Trunk Monkey mentioned, it's temporary and does wash off. I like the Project Farm dude. Based on his results, take a look at CRC Heavy Duty Corrosion Inhibitor. Seems to stay on well.

 

[SlowBuild]

Fluid film is meant to be a temporary barrier between metal and corrosives. For your area with little rust to worry about I'd just sand if needed to get some of the surface off and go to town with Krylon. But, realize it's going to look that way again in a few months.

I would agree. I use an oil undercoating here in NH where we’re constantly battling road salt but it’s nasty stuff. I have to reapply it every year and everything I touch under the truck is coated in oily mess. It oozes out through body seems and gas cap cover etc. onto paint. I plan my maintenance to do as much work as I can in the fall before I reapply it cause I don’t want to touch the truck at least until next summer once it’s sprayed. I hate the stuff but I think it’s a necessary evil here where I live to stay ahead of the rust.

Your truck looks pretty clean underneath, I’d try to keep it that way. Remove splash guards and sand/paint. Maybe address parts as you have to handle them periodically for maintenance. Looks like mild surface rust and only cosmetic. I would touch up a bit at a time as you work under there. Stay away from Fluid Film etc unless you really need it. (I use NH Oil Undercoating but I think it’s similar stuff.)