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Crack in a carbon fiber seat

Discussion in 'Technical Q&A' started by Jim Riggs, Apr 8, 2004.

  1. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    #1 Jim Riggs, Apr 8, 2004
    Last edited by a moderator: Sep 7, 2017
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  3. Bertocchi

    Bertocchi Formula 3
    Consultant

    Jan 28, 2004
    1,882
    New Orleans, LA
    Full Name:
    David Castelhano
    This is similar to the repairs needed on the F40s. First 348 I have seen with carbon fiber seats! The upholstrey should be removed and reinforcing added to the inside of the seat shell. I would get after it before it gets worse. Cools seats!
     
  4. Noelrp

    Noelrp Formula Junior

    Aug 30, 2001
    630
    SSF
    Full Name:
    Noel
    My SS seats(in black leather) have similar damages. I pulled them out & replaced them with standard 348 seats. They are more comfortable & can take more abuse.

    A set of standard seats can be purchased around $1500.
     
  5. JPF

    JPF Formula Junior

    Sep 11, 2003
    525
    NY
    Full Name:
    Joshua
    Is it true they are called the "Frau" seats?
     
  6. Auraraptor

    Auraraptor F1 World Champ
    Lifetime Rossa Owner

    Sep 25, 2002
    11,556
    MO
    Ask Valence, our sponsor, as they are experts on CF.

    Ask for Chris.

    Highly recommended.
     
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  8. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,662
    In general, if the carbon fiber is/was used in a structural application and has cracked you cannot make it whole again in a structural sense.

    You can patch it alal fiberglass, but be aware that you never regain the origianl strength.

    I don't know if the lumbar portion of that seat is structural or not.
     
  9. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    Mitch-

    I would expect that the lumbar portion of the seat has little stress on it when someone is setting in the seat. I think that the primary stress and probably cause of the crack is when contact is made with the lumbar entering or exiting the seat. That is, if someone hits the outside edge of the lumbar section, I would expect that it would create some large stresses.

    Thanks, Jim




     
  10. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
    2,956
    Suggest you drill a hole at the end of the crack to distribute the load and minimize further cracking. The round hole minimizes the stress riser. Do that now. Repair the interior with FB at the earliest opportunity.
    Rgds,
    Vince
     
  11. 4re gt4

    4re gt4 Formula 3

    Apr 23, 2002
    2,279
    Roseburg, OR
    Full Name:
    Hans E. Hansen
    Concur on drilling the hole. This is commonly done with just about anything - plaster, metal, plastic, etc. Especially glass. Stops the crack.
     
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  13. tifosi69

    tifosi69 Formula 3

    Dec 23, 2003
    1,671
    Atlanta, Ga.
    Full Name:
    Al-Al Cool J
    Jim, can't offer any advice but I would like to ask you how you like the 348? I am considering a '94 and would like your comments, awesome seats by the way, I heard the Series Speciale is an awesome car, the best "unloved" Ferrari ever made, read a cool article in Forza about it.
     
  14. RAYMAN

    RAYMAN Formula Junior
    BANNED

    Mar 10, 2004
    315
    Oklahoma
    Full Name:
    Raymond Santilli
    The 348 gets bashed pretty good in the Forza Buying Guide, never the less I love my 92' SS, hard shifter, crappy interior finish and all.
     
  15. Ricambi America

    Ricambi America F1 World Champ
    Sponsor Owner

    I love my 90 348ts. Maybe because it's my "first". They say you never forget your first love. ;-)

    Screw the pundits. They can take their V12 garage queens to the concours. I'm going driving.
     
  16. rexrcr

    rexrcr Formula 3

    Nov 27, 2002
    1,572
    Kalamazoo, MI
    Full Name:
    Rob Schermerhorn
    Jim,

    The crack you see is caused by the driver entering/exiting and slightly bending/flexing the "wing" of the seat laterally as viewed from above the seat. CF doesn't like stress in bending, it's actually quite brittle, which is why many composite seats are CF/Kevlar blend, attempting to get the best of both worlds.

    From what I can see, it's the clear coat/ gel coat that's cracked, hard to tell if actual fibers are broken. This can be repaired, both structurally and cosmetically, but you need someone with tons of experience. They'll probably do a wet lay-up of additional CF both inside and out.

    Here's my suggestion:

    The passenger and driver upper/ torso portion of the seats are most likely interchangeable. Remove both seats from the car, very carefully disassemble the seat uppers, pay attention to each fastener's location, they may be different lengths. Use an Allen head socket place squarely in the fastener, it's easy to round-off the hex on these screws. Careful on reinstallation to avoid cross-threading, it's easy to do on these composite seats.

    Manually reclining the seat may ease dis- or re-assembly.

    You should be able to determine if this will work before tearing them apart.


    Best regards,

    Rob Schermerhorn
     
  17. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    Rob-
    Super idea! I had not thought about interchanging the upper portions of the seats. If I am able, it would place the lumbar support that has the crack in a location where it would be unlikely to receive much stress in the future. It would allow me to continue drive my F-car albeit without a passenger seat while I have the lumbar area repaired. Thanks, Jim
     
  18. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    20,548
    socal
    This is a problem with all CF seats. Some race sanction bodies require back braces because of this.. The ss seats are cosmetically desireable but in a street car should not be done imo since they get zero care.. The wing is very important because it holds you in with side impacts. The "whole" seat is a safety device...don't screw with it unless you know what you are doing. See Rexrcr's post and head his advice.
     
  19. Valence

    Valence Formula Junior

    Jan 20, 2004
    875
    Charlottesville, VA
    Full Name:
    Chris& Brian Coffing
    DO NOT drill holes in the seat. Composite materials are fundamentally different from homogeneous materials like metal and plastic. Cracks propagate differently in composite materials, and composites react differently to stress-raisers like holes and sharp inside corners. Actually, these differences typically work out in favor of composites, which, as a general rule, have excellent fatigue lives compared to metals. By drilling a hole, you would simply remove good material, and further weaken the part.


    Regarding the repairability of composites, it is also incorrect to assume that carbon fiber composites, even in srtessed situations, cannot be repaired to meet or, as is more commonly the case, exceed the original strength of the part. Repair is a major sector of the high-performance composites industry. Composite military and civilian aircraft are repaired with tremendous sucess many times every day, all over the world.

    Automotive applications really aren't that exotic, and there's no reason why any well-equipped and knowledgeable composites shop can't fix your seat, and quite literally make it better than it ever was.

    Fiberglass patches certainly won't do the trick, but a well-placed carbon fiber/epoxy repair will.

    It will, of course, be an ounce or two heavier, but I suppose you could just skip the fries with lunch and it will all work out.

    -Chris
    Valence USA
     
  20. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    I pulled the uppers of my seats this afternoon. Rob was right that the driver and passenger uppers are interchangeable. I'm going to send the damaged upper to Chris at Valance on Monday. Cheers, Jim
     
  21. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    Just a note to reach closure on this thread. I just received my upper carbon fiber seat, which was reparied by Valence (FerrariChat Sponsor). I cannot tell that it was ever damaged and it is stronger than original. Chris at Valence is suppose to post some before and after pictures of the seat. These guys know their carbon fiber materials. Cheers, Jim
     
  22. 348 Turbo

    348 Turbo Formula 3

    Jul 17, 2002
    1,837

    Good post. I read, and learned.
     
  23. Noelrp

    Noelrp Formula Junior

    Aug 30, 2001
    630
    SSF
    Full Name:
    Noel
    That is great that Valence was able to fix your seats. I love to see the before & after pictures.
     
  24. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    #21 Jim Riggs, May 3, 2004
    Last edited by a moderator: Sep 7, 2017
    Attached is a photo of the carbon fiber seat that was repaired by Valence. By comparing it to the previous photos you can see the improvement in appearance. In fact, although the attached photos shows a crack line, it is much more apparent in the photo than to the naked eye. But I must emphasis that due to the reinforcing on the inside, this wing is much stronger than original.

    So much for the good new. After I installed the upper portion of the seat in my 348SS, I noticed a hairline crack on the same upper but in the wing opposite the one that was fixed. It is also structurally weaker than it should be, but not as much as the one that I had fixed. I think that these wings are the "hangnail" of these carbon fiber seats. I am going to have to send the upper back to Chris at Valence so I think that I'll send both uppers to have the all reinforced. That way I don't have to get nervous everytime someone gets into a seat.

    Cheers, Jim
    Image Unavailable, Please Login
     
  25. Jim Riggs

    Jim Riggs Karting

    Jan 25, 2004
    85
    I just wanted to wrap up this thread. After I got the upper portion of the driver's seat back from Valence, I noticed a thin crack on the opposite wing that I had not noticed before. After checking the wings on the other seat upper, I found that they were rather weak and susceptible to damage if someone were to improperly enter the seat. So I decided to send both uppers to Chris at Valence to have the three remaining wings reinforced. When Chris did this he found that only one of the four wings were without failure cracks and the one without cracks appeared to be near failure. It is clear to me that the lack of adequate reinforcement on the wings is a "design flaw" for the 348 Series Speciale carbon fiber seats. Chris said that he will post some photos showing the condition of the wings and the result of the reinforcing process. Cheers, Jim
     
  26. kirill

    kirill Formula Junior

    Jul 8, 2004
    579
    Illinois
    Full Name:
    Kirill
    Guys, I am not a F owner - just browsing.
    Can't this be reported to NTHSA as a safety issue ? F should be forced to do a recall on this.
     
  27. sherpa23

    sherpa23 F1 Veteran
    Silver Subscribed Owner

    May 28, 2003
    9,511
    Colorado
    Full Name:
    Bastuna

    A recall? Ferrari? Especially with sport seats? Wow, you really are a newbie.

    Keep browsing the threads. You'll see a lot more things that should be recalled long before sport seats but won't ever be.
     
  28. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
    27,422
    Austin TX
    Full Name:
    Brian Crall
    Recall- Recall, Fred Sanford says grasping his chest
     

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