Under tray repair | FerrariChat

Under tray repair

Discussion in '360/430' started by 78bonanza, Oct 27, 2020.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. 78bonanza

    78bonanza Formula Junior

    Apr 1, 2018
    331
    Full Name:
    Jim Cear
  2. fotostars

    fotostars Formula Junior

    Feb 6, 2015
    341
    Bay Area
    I fixed mine using a fiber glass repair kit available at your Auto Parts store... Then matte black rattle can paint if you're really anal about it.
    Just make sure you rough the surface with 80grit and thoroughly clean before laying out the composite and the mesh...
     
  3. AandSC

    AandSC Formula Junior
    Silver Subscribed

    Dec 12, 2016
    757
    Jax, FL
    Full Name:
    Allen
    colorfull and armedferret like this.
  4. armedferret

    armedferret Formula 3

    Mar 24, 2018
    1,120
    Maryland
    Full Name:
    Mark
    nice work!!
     
  5. AandSC

    AandSC Formula Junior
    Silver Subscribed

    Dec 12, 2016
    757
    Jax, FL
    Full Name:
    Allen
    Thanks! I could have done a little better job cleaning up and painting the area but I wanted to make sure it would hold up first. Has worked well so when I pull off the bumper next time I’ll make it look nicer.
     
    armedferret likes this.
  6. armedferret

    armedferret Formula 3

    Mar 24, 2018
    1,120
    Maryland
    Full Name:
    Mark
    Eh, aesthetics are easy to correct, function and robustness always takes shotgun. Once those are resolved, like you said, easy to address the rest.
     
    one4torque, TheCook and AandSC like this.
  7. rotaryrocket7

    rotaryrocket7 Formula Junior

    Dec 7, 2011
    580
    Eden Prairie, MN
    Full Name:
    Matt
    a lot of times that's intentionally broken because two post lifts are unable to take off the under tray without first raising the car, undoing all of the screws, then lowering and removing the post arms to remove the tray and re-lifting (reinstall is also a PITA).
     
    AHudson and TheCook like this.
  8. TheCook

    TheCook Formula Junior

    Oct 16, 2015
    304
    Buckinghamshire
    Full Name:
    Ian
    Love it. I need to repair the rear undertray and this thread has decided the method for me. Thanks. I had to replace the front as it was beyond repair but found one for around £200 so not too bad.


    Sent from my iPhone using Tapatalk
     
  9. FiatAbarth850

    FiatAbarth850 Karting

    Aug 2, 2020
    100
    Winnipeg, Manitoba, Canada
    Full Name:
    Bill H.
    The undertray is made of plastic isn't it? I'd use the plastic welding and metal stitching method shown in this video. I've used these methods successfully on the plastic bodywork on my Honda ATV. With a light hand the repair comes out very strong and hardly visible.

     
    armedferret likes this.
  10. sparetireless

    sparetireless Formula 3

    Nov 2, 2003
    1,529
    easy fix, any boat shop can do it, its just fiberglas
     
  11. Sj_engr

    Sj_engr Formula 3

    Sep 15, 2020
    1,280
    San Jose
    Full Name:
    dc
    Cheaper than the fiberglass kit is buying a mat of the fiberglass from the auto store & 15min JB Weld plastic epoxy for $5 from Amazon.

    Busy with building new bumper tabs and repairs to the under tray this week. 80 grit scuff and the jb weld is easy to work with as it dries.

    You could even lay a rod or stiff wire perpendicular and just use the epoxy
     
  12. Sj_engr

    Sj_engr Formula 3

    Sep 15, 2020
    1,280
    San Jose
    Full Name:
    dc
    Just snapped a pic after shaping excess w a dremel. Looked like someone tried a fiberglass reinforcement before or from the factory?

    View attachment 318687

    Just need to wait for the sill nut to arrive and drill a hole and press on.
     

    Attached Files:

    sparetireless and armedferret like this.
  13. JM280z

    JM280z Formula Junior

    Aug 22, 2020
    685
    Full Name:
    Jake
    I used plastic welding and metal mesh. The under tray flexes too much and it started peeling off. I cleaned it all off then used fiberglass repair kit and that worked perfect.


    Sent from my iPhone using FerrariChat.com mobile app
     
  14. one4torque

    one4torque F1 Veteran
    Silver Subscribed

    May 20, 2018
    5,088
    Houston
    Full Name:
    One4torque
    Fiberglass mesh weave and 2 part resin …. Easy job.

    sand and paint to your level of ocd.
     
  15. colorfull

    colorfull Formula 3
    Silver Subscribed

    Sep 12, 2020
    1,905
    Franklin Park, New Jersey
    Full Name:
    John Napoli
    I had a fiberglass kit ready to go, but was told the undertray is some sort of ABS plastic, not fiberglass (though I expect it would work fine)

    Additionally, I had to repair the corner tabs and didn't think repairing the cracks alone would be sufficient, they are very weak considering they hold the undertray to the car.

    So I purchased a sheet of ABS plastic, cut it to shape, and used JB weld

    It is now a solid joint that is significantly stronger than the initial, flimsy tabs

    Apologies for the poor pic, I'll upload more info if anyone is interested Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
     
    van22 likes this.
  16. Sj_engr

    Sj_engr Formula 3

    Sep 15, 2020
    1,280
    San Jose
    Full Name:
    dc
    Nice work. The JB weld stuff adheres amazingly well. I even cut was able to a shape with a dremel for the fiber/jb.
     
    colorfull likes this.
  17. colorfull

    colorfull Formula 3
    Silver Subscribed

    Sep 12, 2020
    1,905
    Franklin Park, New Jersey
    Full Name:
    John Napoli
    Thank you

    Agreed, like plastic concrete but better, and pretty easy to use as far as epoxy goes
     
  18. Sj_engr

    Sj_engr Formula 3

    Sep 15, 2020
    1,280
    San Jose
    Full Name:
    dc
    Glad you found it. I wasted a lot of tine delicately filling hairline cracks with model airplane glue. That glue peeled off right away after waiting a long time to dry.

    Redid it in epoxy and I bet in an impact the JB weld would be survive vs original plastic.
     
    colorfull likes this.
  19. clean512

    clean512 Formula 3
    Silver Subscribed

    Feb 4, 2010
    2,017
    Full Name:
    Josh @jtcarprojects
    In my body shop field we will use Wurth or 3m panel bond. It looks like jb but definitely better. Can glue qtr panels back on with this stuff.
     
    kes7u likes this.
  20. colorfull

    colorfull Formula 3
    Silver Subscribed

    Sep 12, 2020
    1,905
    Franklin Park, New Jersey
    Full Name:
    John Napoli
    @clean512 thanks for the tip. I have to epoxy a side piece in place on sport seats and the person who did the initial repair recommended using Wurth, good to know its 'worth' the price! not that it's that expensive...
     
    clean512 likes this.
  21. Danedingerson

    Danedingerson Karting
    Silver Subscribed

    Dec 26, 2011
    218
    Maui
    Full Name:
    Dane
    Use a layer of peel ply that looks like white cloth on top and peel it off after. It looks nicely sanded with little effort.
     

Share This Page