Rust on underbody paint

Was underneath this week removing my frame sliders to sand and repaint them due to rust and noticed a spot on the underbody that is starting to rust a bit. Pretty mild for a 2017 but I'd rather treat it now before it eats away at it. What would you guys do? I'm thinking sand away the rust slightly, apply phosphoric acid, clean, use touch up paint and clear coat, then just apply Cosmoline this fall to the areas.

 

I'd wire brush off the rust, apply a rust converter, and then paint it. Cosmoline to finish it off. Its one of the areas i hit good with cosmoline on my new tacoma seeing the same what happened on my old tundra in that area when i only fluid flimed it once a year. They use a tremendous amount of salt and brine on our roads 4-5 months out of the year.

 

I FF and cosmoline the shit out of my frame and areas, but for some dumb reason i left that area alone every fall. Stupid me. I'll be sure to pay closer attention to that area when i treat the underside in the upcoming weeks

 

Never mix fluid flim with cosmoline.

 

nope, i use cosmoline for the main areas of the underbody,frame since its more durable, But for the harder to reach areas and those that require creeping, i use ff

 

I had no issues using rp-342 cosmoline. That stuff creeps into everything having a solvent to thin it down.

 

Good to know, i bought a box of 12- CRC corrosion inhibitor on a sale a few years ago and i've been going thru those. I find it coats really well, but doesn't run all that much, which is great for limiting the mess it makes. On the other hand, FF is a fucking mess haha

 

the underside of the rocker panels are always covered in road tar. free rust protection i guess courtesy of the county...

 

Now is a good chance to black out the pinch welds. It makes them pretty much vanish when looking at the side of the truck and will fix your little bit of rust.

https://www.tacomaworld.com/threads/diy-pinch-weld-paint-mod-walkthough.507696/

 

Oh dang that looks good. I have a can of POR-15 i used to paint on my rusted frame sliders that i just recently re-did. I was thinking of painting that on the bottom of the rockers, but im afraid it might "trap" moisture in That POR stuff is freaking incredible in how strong it is.

 

Also while you are down there (after you paint the rocker) pull all those black rubber plugs out, spray the hell out of the inside of the rocker with fluid film, then put the plugs back in.

 

I sprayed that rp-342 in mine...stuff was dripping everywhere after i was done. It was just as bad of worse than fluid flim. Those cosmoline rp-342 droplets are like jennite for coating an asphalt driveway.