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Bonding steel to fiberglas

Discussion in 'The Hokey Ass Message Board' started by Koz, Apr 26, 2012.

  1. Koz
    Joined: May 5, 2008
    Posts: 2,343

    Koz
    Member

    This is new to me but I need to bond some steel panels to some fiberglas body panels. Whats the hot set up here? Will regular body bonding agent work or do I need something special?
     
  2. It's a myth. The 2 don't actually bond together. You can only incase the steel between 2 layers of glass. It helps to drill 3/4" holes in the steel but eventually it will come apart.
    The Wizzard
     
  3. boss_hoss
    Joined: Mar 5, 2012
    Posts: 6

    boss_hoss
    Member
    from Oregon

  4. morac41
    Joined: Jul 23, 2011
    Posts: 532

    morac41
    Member

    Hi ... It might bond for a while ...its only temporary... it dont work satifactory....
     

  5. MP&C
    Joined: Jan 11, 2008
    Posts: 2,356

    MP&C
    Member

    Typically steel and fiberglass have differing expansion rates, so any exposure to varying temps will over time cause the delamination of your bonding agent for a separation of the panels. The hot setup is to keep steel with steel and f/g with f/g for a more permanent repair. Mix them together, and it is temporary.
     
  6. Best i found for adhesion was to mix a bit of 'bondo' into the fiberglass but it's best not to use fiberglass on steel. The fiberglass i'm talking about is the kitty hair type in a can.
     
  7. Nads
    Joined: Mar 5, 2001
    Posts: 11,632

    Nads
    Member
    from Hypocrisy

    chalk aND CHEESZE
     
  8. Skeezix
    Joined: Jan 10, 2007
    Posts: 845

    Skeezix
    Member
    from SoCal

  9. olkarz
    Joined: Aug 7, 2010
    Posts: 114

    olkarz
    Member

    I've always had good results drilling several small holes through the steel, so that the resin can seep through, using a couple of layers of chop mat on the backside of the steel panels and finishing the top of a fiberglass panel off with some Dynaglass. Countersinking some sheetmetal screws or pop rivets into the fiberglass panels is a great help also, it'll keep the fiberglass panels from shifting.
     
  10. Elmer Rodger
    Joined: Dec 30, 2010
    Posts: 35

    Elmer Rodger
    Member
    from San Diego

    marine tex epoxy will be your best bet, like olkarz say's some holes drilled in the steel will help
     
  11. hit the metal with 36 grit paper first.something to bite to.fiberglass resin will work fine,and seal your work.
     
  12. Kerrynzl
    Joined: Jun 20, 2010
    Posts: 2,284

    Kerrynzl
    Member

    Use a Urethane Adhesive / Sealant [ not straight urethane sealant it is slightly different ]

    I've used it to glue a front end to the birdcage on my corvette race-car.
    and also trailer fenders onto trailers.

    I have also used it to glue 1/8 diamond plate decking onto a trailer frame , there was no heat warpage [ and it"s stronger than stitch welding because the bonded area is greater ]

    My prefered brand is "SIMSON" ISR 70-03 by Bostik

    I wouldn't hessitate to glue a whole Hotrod together with the stuff [ provided the design was correct ]
     
  13. nachodog
    Joined: Dec 24, 2009
    Posts: 111

    nachodog
    Member
    from socal

    Look into 3M 8115 adhesive. You need a special gun for it but it works really good.
     
  14. Koz
    Joined: May 5, 2008
    Posts: 2,343

    Koz
    Member

    Thanks guys! I'm doing something a little special here. I'll post up shortly.
     
  15. do a search, this has been covered here many times......and the short answer is... IF you know how= it works very well and will last a long time.
    this hood scoop is glass, on a steel 4 peice hood[ welded up into one peice clip]....both things said to not be possible ,and to make last....
    this 40 Pontiac coupe I built has held up very well and is still being shown on the east coast after more than 16 years since bonding the two together......
     

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    Last edited: Apr 27, 2012
  16. Crystal Blue
    Joined: Nov 18, 2008
    Posts: 609

    Crystal Blue
    Member

  17. Gearhead Graphics
    Joined: Oct 4, 2008
    Posts: 3,799

    Gearhead Graphics
    Member
    from Denver Co

    at Zipper's we used "bear shit" that was made in house. Sadly I've forgotten what was in it, but id venture to guess it was along the lines of kitty hair bondo, figerglass resin and hardener. Glopped on between the glass and metal, and then encasing the metal as well.
     
  18. MP&C
    Joined: Jan 11, 2008
    Posts: 2,356

    MP&C
    Member


    Dan? What did you guys use on Sam's hood scoop?

    Here's a more recent pic....

    [​IMG]
     
  19. TwistedMetal
    Joined: Nov 2, 2006
    Posts: 45

    TwistedMetal
    Member
    from wisconsin

    West systems epoxy mixed with I think it is their 404 powder for dissimiar materials. This forms a paste. This seems to hold very well. You can use the WS with a tight weave cloth too. I use this for a bond/sealer but not a high structure area.
     
  20. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    Already mentioned, encapsulate the steel into the part with fiberglass and resin. Do a course sanding of everything first. Epoxy resin is better stronger(and more expensive) than "regular" polyester resin.
     
  21. I have taken four different courses from Abaris, If they cant bond it, it can`t be done. Who is your friend? first name only.
     
  22. Mike?? is that your name[Sams cousin I presume?], my name is Kenny, Dave Talent's SHOP did the paint work,on The car I did the FABRICATION WELDING AND ALL Initial BODYWORK UP TO FINAL BLOCKING/ PAINTING.....

    I used Bondo glass [3M] from Wal Mart:cool:......

     
  23. firstgear
    Joined: Jun 11, 2011
    Posts: 112

    firstgear
    Member

    I mounted a metal plate that I had mounted my Accel box to the fiberglass body of my '60 Corvette. I drilled a number of holes in it like previously mentioned and sed 3M 8223. That was 5 years ago and it hasn't fallen down yet.

    As a side note, every midyear coupe (1963-1967) has a structural steel frame known as the bird cage and fiberglass bonding panels are bonded to this steel fame (this is what the body panels are bonded to) and have held up for almost 50 years.

    Do a google search and you will get suggestions.
     
  24. Generally speaking this is a recipe for disaster. It may look good for 2, 3, 4, maybe even 5 years but in the long run it's going to be a mess. As already mentioned the differences in the material characteristics is the problem. Steel and composites have widely differing coefficients of thermal expansion. You also have to think about corrosion. If any moisture gets trapped between the steel and fiberglass it's going to get nasty.

    There may be some tricks you can pull...like drilling a lots of holes to let the glass flow through the steel or cutting slots in the steel to allow it to expand with the glass and encasing the steel in glass.... but still this is not a good long term plan.

    If you're ok with this just looking good for a few years and re-doing it later then that is up to you.
     
  25. MP&C
    Joined: Jan 11, 2008
    Posts: 2,356

    MP&C
    Member


    I'm Robert, I used to work for Mike until a couple years back. I did get a chance to meet Sam before his passing, and even gave him a couple rides to the hospital, as volunteer in local rescue squad...
     
  26. Koz
    Joined: May 5, 2008
    Posts: 2,343

    Koz
    Member

    Man! I never expected such a response on this subject. I've come to the conclusion this "ain't gonna work". I,ve never owned a car more than a year or so but I don't want to hang the next guy with my substandard work so I've decided to just make full panels out of 18ga. and skip the bonding entirely.
     
  27. Skeezix
    Joined: Jan 10, 2007
    Posts: 845

    Skeezix
    Member
    from SoCal

    Jay
    With Mikes blessing we used to offer phase 1 courses at my old shop at Sears Point
     
  28. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    I have seen numerous race boats where steel is glassed into the boat's structure. Not an expert on this, but I have seen cases where the glass failed, but not the bond to the steel. I know some of the older Corvettes had steel somehow bonded into the car's fiberglass. Is something different done in those situations, or do those cases eventually end up a "mess"? There are LOTS of cases where wood structure and fiberglass have been combined in boats and car bodies. Wood and fiberglass are dissimilar materials. And like metal, wood is adversely effected my moisture. Do those applications eventually turn into a mess, even if they are done right?

    Some car and truck manufacturers are successfully gluing body panels together with some kind of adhesive(urethane I believe) that tolerates vibration, expansion/contraction, moisture, etc. Whatever that material is, maybe it's a possibility?
     
    Last edited: Apr 28, 2012
  29. 1971BB427
    Joined: Mar 6, 2010
    Posts: 6,689

    1971BB427
    Member
    from Oregon

    I've got 37 yrs. on my glass to steel bonded fenders, and people still tell me it's going to come apart someday. Hope I'm alive to see it.
     
  30. BJR
    Joined: Mar 11, 2005
    Posts: 6,853

    BJR
    Member

    I have done it for years (I'm 62), just body panels, nothing structural. I have never had a problem or even a stress crack. Back in the 70's I put 4 fiberglass fenders on a 56 Bird when no steel ones were available, and 10 years later they were still fine. Just my experience, but what do I know.
     

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