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What is the Plasticy Stuff on the Rear Wheel Well Flanges?

Discussion in 'Gen 2 Prius Technical Discussion' started by Rokeby, Oct 2, 2008.

  1. Rokeby

    Rokeby Member

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    If you run your fingers along the metal flange where the rear fenders
    form the outer lip of the wheel wells, you can feel a bead of some stuff
    that is clearly not metal. From its slightly irregular surface, it would
    appear to be some highly viscous plastic/polymer applied from
    something like a caulk gun. After it dried/cured/polymerized, it was
    painted over when the panel/body was finished.

    What does it do? Why is it there?

    Can anyone positively identify it by name and manufacturer?
     
    #1 Rokeby, Oct 2, 2008
  2. dogfriend

    dogfriend Human - Animal Hybrid

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    In the Body Repair manual, it is identified as body sealer. There is no brand or spec given as far as I can see. The purpose is given as an anti rust treatment. The body repair manual gives the location(s) and whether a bead is used or a flat finish.
     

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    #2 dogfriend, Oct 3, 2008
  3. David Beale

    David Beale Senior Member

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    In the "old days" body panels were soldered together after spot welding to seal the gap that would always result from joining two panels together. This takes a lot of time, even on a production line.
    So they came up with the elastomeric caulk. It's probably a 3M one, as they seem to come up with all the cool glue stuff first. The soldering is still done, but on a very limited number of spots.

    This treatment keeps salt water from seeping into areas that would result in the body falling apart after two or three years. That -used- to be the norm. Now cars tend to last longer with some of the new techniques used. The new glues are so good that in some cases they don't even spot weld them any more.

    Another change that occurred in the eighties was the rocker panel flange we now see under the panel. That used to be folded over and soldered.
     
    #3 David Beale, Oct 3, 2008
  4. Rokeby

    Rokeby Member

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    David Beale, dogfriend,

    Fellow Brothers in the Order of the Celestial Prius,

    Thank you very much. This is exactly the info I was hoping I could find.
    Item 4 (b) (1) is the application in the wheel well; and it is to protect
    the thin metal flange from rock damage and subsequent corrosion. It is
    comforting to know that Toyota thinks about something like this.

    I see that its removal, say to mount wheel skirts, wouldn't necessarily
    cause a problem as the skirts would cover and protect the flange.

    My first job in high school -- Bedrock High, Go Dinos! -- was at a car
    wash. The workforce consisted mostly of 30 to 50 year old reprobates and
    ne'er-do-wells. As the FNG, my job was to wash the tires/wheels with a brush.
    To do the job well, I had to reach up into the wheel well. Often times the
    edge of the flange had rusted to a serrated knife edge rhat would take
    the skin off the back of my hand in a heartbeat -- I was truely desperate
    for some spending money. The strong soap kept a true scab from forming,
    but overnight the wound would seal over with a transparent dried serum
    film. Not a pretty sight.

    After two weeks, on the day before payday, the owner locked the
    doors and walked away. !@#$% SOB. I lost a hot date to go to Hershey
    Park because I had no dough-ray-me. Life right and truely sucked.
     
    #4 Rokeby, Oct 3, 2008
  5. jelloslug

    jelloslug It buffed right out!

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    There 3 different materials used in the undercarriage of the Prius:
    1) Seam sealer. It's usually packaged in caulk tubes or in quart cans (I prefer the caulk tubes). It like a very thick caulk and never dries hard. It's used all over the car inside and out anywhere there is a seam between metal surfaces. Want to see more of it? Take you spare tire out; you will see more if it there.
    2) Foam sealer. This stuff is a very sticky thick foam that seem to only be in the wheel well areas. This is is used to fill larger gaps that the seam sealer will not do as good of a job.
    3) Undercoating. This stuff is a thick, black, rubbery coating sprayed in the wheel well areas after the seam and foam sealers are applied. It helps prevent debris from the tires damaging the sealers, prevents water intrusion, and dampens noise.
     
    #5 jelloslug, Oct 6, 2008
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