What type of plastic was used in our cars?

Restoration

  1. Zymurgy

    Zymurgy Senior Member

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    I was looking at various searches and came across an article about making a paste with ABS plastic and acetone to make plastic repairs. What type of plastic is in our 60s cars? I think of ABS plastic are an 80's to the current modern cars. Am I correct in this thought? Didn't think this ABS putty would work on our car or would it?
     
  2. stubs300

    stubs300 Well-Known Member

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    What are trying to fix?
     
  3. Zymurgy

    Zymurgy Senior Member

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    It all started as questionable condition bumper surround for a '69 300, but came across this post on repairing ABS and found it interesting. Still not certain whether the surround is plastic or fiberglass.
     
  4. OneEyed

    OneEyed Active Member

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    Plastic will melt and fiberglass wont. Grab a needle with a visegrips, heat it up and stick it into an unseen area.
     
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  5. Zymurgy

    Zymurgy Senior Member

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    You guys have all the tricks, thanks.
     
  6. cm23uoc

    cm23uoc Old Man with a Hat

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    I suspect some interior parts to be made out of Cookie dough on my 1970 Chrysler.
     
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  7. 67Monaco

    67Monaco Senior Member

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    Because they are yummy?
     
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  8. cm23uoc

    cm23uoc Old Man with a Hat

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    More like crumbly.
     
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  9. bigmoparjeff

    bigmoparjeff Member

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    I'm pretty sure that they were made of fiberglass, which means they are very repairable.

    Jeff
     
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  10. CBODY67

    CBODY67 Well-Known Member

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    IF it was fiberglass, it would require special handing (usually gloves) somewhere in the process. I'm suspecting "plastic" unless it is metal with special paint (as my '70 Monaco is). I believe that "ABS" is a molding process rather than a particular formula for "plastic"? The whole '72 Newport grille is plastic with metal accents, so I suspect your 300 surround is probably plastic, too.

    As with the fiberglass Corvette bodies and repair parts, they are heavier than a similar sheet of plastic by a good bit. Look on the back side for the casting information (part number/casting number) on if it's a particular type of plastic. IF it's "twistable", gently and not much, then it's plastic as fiberglass does not do that, by observation.

    In other words, them "laying up" fiberglass and resin to get to the finished product is a much more labor-intensive (and time consuming) process than doing it in molded plastic. Think "hours" rather than "minutes", for example, all of which increases production cost. There might be some DIY YouTubes on how to do fiberglass repairs on a '60s or '70s Corvette, which will detail that process.

    CBODY67
     
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  11. Zymurgy

    Zymurgy Senior Member

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    Thanks for the great information, I learn something new on this site nearly every day.
     
  12. HWYCRZR

    HWYCRZR Active Member

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    I have had some success welding some of the plastic parts on my 68. I had to make some ears for my heater ducts. I ended up using a heat gun and some body plugs which seems to be close to the parent material. Since they go under the dash I wasn't too concerned about the looks. I had to recreate one of the ears
    image.jpg

    Since then I bought a plastic welder from Harbor freight. It's muchmore precise. The difficulty has been finding the right parent material. I want to practice more before I weld my radiator rock guard.
     
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  13. Zymurgy

    Zymurgy Senior Member

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    Didn't even know they made plastic welders. Based on the reviews I should have the perfect compressor to work with the welder. I have a small one I use with my air brush. Once again thanks for the info.

    This got me thinking of a Christmas gift I got when I was young, and did a little search. Here to find out, I had a plastic welder when I was about 8. :)

    spin welder.jpg
     
    Last edited: Oct 12, 2017
  14. pomonamissel

    pomonamissel Senior Member

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    yes plastic welding is done on all types of plastic todays cars are mostly plastic crap , and most body shop have a plastic welder . but i've seen guys use the acetone and plastic filings to make a paste to make repairs on grille parts before . after finish sanding and repainting the repairs are great looking , as good as new in most cases .
     
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  15. stubs300

    stubs300 Well-Known Member

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    You can even use Testor's model glue, or super glue & a piece of toilet paper. There's many way to work with plastic, ask me how I know.
     
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  16. Samplingman

    Samplingman Senior Member

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    Yep, I plastic welded the lawn mower's gas tank with an old soldering iron. As for additional plastic material, there is usually flashing or thick corners of the piece you are working on that can be harvested and then grafted to the area in need of repair.
     
    Last edited: Oct 13, 2017
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  17. commando1

    commando1 Old Man with a Hat

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    Tell me more...
     
  18. OneEyed

    OneEyed Active Member

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    A bathtub repair man taught me that. Tip- don't buy plastic bathtubs.
     
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  19. commando1

    commando1 Old Man with a Hat

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    Price a cast iron one these days.. :realcrazy:
     
  20. CBODY67

    CBODY67 Well-Known Member

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    "glue" and toilet paper? Same orientation as fiberglass matting fabric and resin/gel coat. Build up to the thickness/strength desired, machine/finish as needed.

    When we got the first flexible bumper fascias, 3M came out with a repair kit. Sand the split, fill it in, sand like a bondo'd body panel, paint, etc.

    There are some plastics that Super Glue won't glue, by experience. Then I later found out that a dusting of baking soda would make it work.

    ONE trick that a guy from another car club demonstrated to us one day . . . at the hobby shops, they usually have some clear or colored plastic and a kit to take a mold of a small item for reproduction with the new material. He used it to do some smaller round tail light lenses with (on a '40s car). Put the basic mold material in the holding fixture, then add the item you're taking the mold of into it, then add more molding fluid on top of it. Let it all "dry" or cure. Remove the "assembly" from the holding fixture, carefully cut and separate the pieces, remove the original part, then use that mold and the new plastic to make a new lens. It worked quite well, including the casting ID and such.

    Plastic welders have been around for about 20 years now, maybe more like 30. I first heard of them from people doing restorations in the 1980s, when repro plastic parts hadn't been done yet. Probably have to hold your mouth right the first few times?

    CBODY67
     
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