Painting GRP Car - Recommendations?

Discussion in 'Fiberglass and Composite Boat Building' started by Miscbrah, May 26, 2018.

  1. Miscbrah
    Joined: May 2018
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    Location: UK

    Miscbrah New Member

    Hello folks, well I thought I'd come clean before I get started; this is not a boat question really. I've been returned to your forum here a few times from Google etc and thought I might just ask something anyway and see how it landed.

    I'll be restoring a Reliant Scimitar at some point, pictured and some info below:
    [​IMG]
    Reliant Scimitar - Wikipedia https://en.wikipedia.org/wiki/Reliant_Scimitar

    As they're GRP-bodied, I'll be getting (or repairing and arranging for) a galvanised chassis, but the body itself I'd like to renew the finish on. Which is where my quest for information starts, and why I've come asking for info on finishing fiberglass here; there just doesn't seem to be the expertise 'out there' in the automotive world.

    I was thinking I'd be better off just taking the car back to gelcoat and applying a new, black (the 'destination' colour) gelcoat to the body. Perhaps putting on a few layers of gelcoat, sanding it back, re-coating a few times and sanding/polishing back the final coat. Would this be tought and flexible enough to avoid crazing etc? Would anyone recommend going for anything else even? I don't mind taking the prep-time for a longer life free of crazing/cracking, but I've no real experience of finishing fiberglass.

    Thanks anyone who's taken the time to read, hope that's all ok to ask! Any and all replies and suggestions hugely welcome. :)
     
  2. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    Welcome
    Were the Reliants originally finished with gelcoat? Or traditional automotive paint? I thought most fiberglass auto bodies were painted rather than gelcoated.

    Refreshing and polishing tired gelcoat is fairly easy, but laying a new layer of gelcoat is considerably more work than repainting. There are many hoops to jump thru when regeling. Gelcoat is much thicker than paint and is spread to a minimum thickness of 1mm. It's catalyzation ratio is temprano sensitive with potlife measured in minutes. Amazingly, it will not cure hard if it dries, so it must be seperated from immediately after application.

    I would seriously consider auto paint instead od gelcoat.

    Paul
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Agreed, I'd be surprised if the car was gel coat, but just conventionally painted, which is pretty straight forward.
     
  4. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    When the parts are made new they have sanding primer gel coat used in the mold, that primer is painted just like normal primer.

    Your best bet is treat it like a normal automotive paint job.
     
  5. Miscbrah
    Joined: May 2018
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    Location: UK

    Miscbrah New Member

    Folks thanks tons for all that! In that case I'll probably bite the bullet and paint as per 'regular' car. I had pondered brushing/tipping and seeing how far I got with that (marine boat paint sounds temptingly hardy over 2/single-pak paint) and just sanding flat between coats until the final coat. However, if that's not what's recommended then I shan't.

    For ref I think Scimitars were gelcoat in the mould, fiberglass over, then primer and paint. I think.

    Again though, thanks all for the opinions. :)
     
  6. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    You might get good information if you find a Lotus forum and ask there.They are likely to know the brand names of products you can find in the UK and with all the thousands of Lotuses out there,the knowledge base is quite substantial.For long term durability you ought to go with 2K paint and you may have to use a barrier paint over whatever has been applied during the life of the car unless you sand it all off to be sure of eliminating compatibility issues.
     
  7. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    We paint our fiberglass boat with polyurethane and have always primed it with a compatible primer as it is plastic based. Other similar 2 part paint might work as well. Painters advises against painting with acrylic as they say it is brittle when compared to fiberglass. It does not flex as easy hence it cracks.
     

  8. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    My comments were to say you don't need to do anything special, it's a normal paint job, whether you want to spray or roll and tip is your choice.
     
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