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Rust on underbody paint

Discussion in '3rd Gen. Tacomas (2016+)' started by Tacowin1013, Sep 23, 2022 at 5:58 AM.

  1. Sep 23, 2022 at 5:58 AM
    #1
    Tacowin1013

    Tacowin1013 [OP] Well-Known Member

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    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.

    20220922_165520.jpg
     
  2. Sep 23, 2022 at 7:06 AM
    #2
    zoo truck

    zoo truck Well-Known Member

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    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.
     
  3. Sep 23, 2022 at 7:09 AM
    #3
    Tacowin1013

    Tacowin1013 [OP] Well-Known Member

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    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
     
  4. Sep 23, 2022 at 7:10 AM
    #4
    zoo truck

    zoo truck Well-Known Member

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    Never mix fluid flim with cosmoline.
     
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  5. Sep 23, 2022 at 7:11 AM
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    Tacowin1013

    Tacowin1013 [OP] Well-Known Member

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    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
     
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  6. Sep 23, 2022 at 8:55 AM
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    zoo truck

    zoo truck Well-Known Member

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    I had no issues using rp-342 cosmoline. That stuff creeps into everything having a solvent to thin it down.
     
  7. Sep 23, 2022 at 8:58 AM
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    Tacowin1013

    Tacowin1013 [OP] Well-Known Member

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    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
     
  8. Sep 23, 2022 at 8:58 AM
    #8
    cryptolime

    cryptolime Here to Help

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    the underside of the rocker panels are always covered in road tar. free rust protection i guess courtesy of the county...:rolleyes:
     
  9. Sep 23, 2022 at 8:59 AM
    #9
    5nahalf

    5nahalf I build dumb things

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    RustyGreen likes this.
  10. Sep 23, 2022 at 9:05 AM
    #10
    Tacowin1013

    Tacowin1013 [OP] Well-Known Member

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    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.
     
  11. Sep 23, 2022 at 9:07 AM
    #11
    5nahalf

    5nahalf I build dumb things

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    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.
     
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  12. Sep 23, 2022 at 10:08 AM
    #12
    zoo truck

    zoo truck Well-Known Member

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    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.
     
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