Floor Pan Rust Holes

Discussion in 'Chassis restoration' started by Rich Skylark, Oct 19, 2018.

  1. Rich Skylark

    Rich Skylark Gold Level Contributor

    After removing carpet,padding, and underlay I found some minor surface rust and a few pinholes in the driver side front pan. After reading a few posts on this issue I'm thinking wire wheel t surface flake rust, clean entire pan w/a solvent, and seal rust with POR-15. Anybody have any thoughts or if I'm missing anything please chime in . A few Picts of what I'm dealing with,

    Attached Files:

  2. telriv

    telriv Well-Known Member

    Make sure you cover the ENTIRE interior & seal the bottom of the dash. Wire brushing with power tools MAKES A MESS ALL OVER.
    Since the rust is marginal & NOT BAD I would cover the holes with some little pieces of paper & mix up some epoxy & pore it on. Will take the shape of the floor ( if the mix isn't too thin) & ALSO add support.
    Just a thought rather than replacing floor pans which can get to be an involved process.

    Tom T.
  3. Rich Skylark

    Rich Skylark Gold Level Contributor

    I was leaning in that direction Tom, the underside was recently POR-15 ed so with the top sealed up w/ the same the rust should be taken care of hopefully permanently
  4. Golden Oldie 65

    Golden Oldie 65 Well-Known Member

    If you take a wire wheels to the pinholes they will cease to be simply pinholes. POR-15 doesn't work well on bare metal, it is designed to be painted over the rust, hence the name. I would just scrape the loose stuff, maybe take a hand held wire brush and clean it, then use the POR-15.
    TorqueMonster1 likes this.
  5. BuickV8Mike

    BuickV8Mike SD Buick Fan

    Muriatic acid solution on towels for the rust it works magic!!!!!!!!. You have a lot of rust. I like JB weld for the pinholes up to a dime in diameter. ;)
  6. Rich Skylark

    Rich Skylark Gold Level Contributor

    Good idea with JB weld used it many times but never thought about using as a filler for rust holes
  7. 12lives

    12lives Engage! - Jean-Luc Picard

  8. wunquik86'

    wunquik86' Well-Known Member

    I used a fine mesh fiber glass matting with the POR 15. Use as directed when applying, when to re-coat, etc. Hardens like the steel it is sitting on. POR 15 also makes a Silver Paint that has metal filings in it for pitted areas that are not all the way thru. Will harden smooth as the rest of the metal. POR makes a complete kit with the POR 15 that you use to prep the area to be fixed. Cleaner and metal etcher to make the area ready for a professional job. Good luck!
    WQ59B and woody1640 like this.
  9. woody1640

    woody1640 Well-Known Member

    One thing I have learned about POR15 is that prep is very crucial to get great results. POR15 will NOT adhere to painted or just plain bare steel. The steel must be prepped by either acid washing the metal, which etches it or sandblasting it. So far I have only used the sandblasting prep method, but have had excellent results. I did suspension and steering components. I am getting ready to do my floors, trunk bottom, underside of roof, inside doors, underneath entire car, back side of quarters etc.. My floor pan has an area rusted worse than yours and I plan on using the fiber mesh that POR sells to fix it. This time I have stripped (sanded, grinding, little sandblasting etc..) now I am going to use the acid wash method.

  10. dynaflow

    dynaflow shiftless...

    TorqueMonster1 likes this.
  11. copperheadgs1

    copperheadgs1 copperheadgs1

    TorqueMonster1 likes this.
  12. dynaflow

    dynaflow shiftless...

    ...rust radiates from cowl/pillar area...
  13. copperheadgs1

    copperheadgs1 copperheadgs1

    I have seen many many cars with holes in floor and no rust at all on area that curves up to meet firewall.
  14. dynaflow

    dynaflow shiftless...

    Agree...but with amount of topside pan rust and harness channel appearing to act as dam, this one looked like cowl leak soaking jute...
    bostoncat68 likes this.
  15. Rich Skylark

    Rich Skylark Gold Level Contributor

    image.jpg image.jpg image.jpg image.jpg image.jpg image.jpg Looks like water was entering by way of drivers side kick panel. Applied POR-15 rust remover yesterday and lightly wirebrushed the loose scale. Looks like a previous attempt at recaulking the seams see Picts. Most of the caulk crumbled by the door sills will be doing that over. Is this thin black coating in the rear wells original from factory ? Also what is the purpose of these 1" holes in the rear wells and what should be in there ? Thanks for the info
  16. gsgnnut

    gsgnnut Well-Known Member

    Your missing Tue small circular metal plugs for thowe holes
  17. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Looks like you need to bite the bullet and put half a floor pan in. You're past pin holes. You need the proper repair.
  18. Rich Skylark

    Rich Skylark Gold Level Contributor

    Was kinda hoping to avoid changing the pan; car never will see rain but don't want to come back to the problem in a few years with it spreading ; what are the plugs called that I'm missing in the rear pan. Ironically no evidence of rust anywhere around them
  19. dynaflow

    dynaflow shiftless...

    Agree...after reviewing all pics, white residue adds road salt to diagnosis...
  20. Rich Skylark

    Rich Skylark Gold Level Contributor

    The white residue is a byproduct of the POR-15 Metal Prep. This car originated in the south so it probably never salt/snow. Since I've owned it, I doubt it will ever see rain

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